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M5100 SFRA Instrument User’s Guide Doble Engineering Company 85 Walnut Street Watertown, Massachusetts 02472-4037 (USA) www.doble.com PN 500-0295 72A-1849-01 Rev. B 06/02

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Page 1: SFRA User Guide

M5100 SFRA Instrument User’s Guide

Doble Engineering Company

85 Walnut Street

Watertown, Massachusetts 02472-4037

(USA)

www.doble.com

PN 500-0295 72A-1849-01 Rev. B 06/02

Page 2: SFRA User Guide

This Manual is solely the property of the Doble Engineering Company (Doble) and, along with the M5100 SFRA software to which it applies, is provided for the exclusive use of Doble Clients under contractual agreement for Doble Test equipment and services, or have purchased the product and are registered with Doble as end users.

In no event does the Doble Engineering Company assume the liability for any technical or editorial errors of commission or omission; nor is Doble liable for direct, indirect, incidental, or consequential damages arising out of or the inability to use this Manual.

Government Restricted Rights Legend: Use, Duplication, or Disclosure by the U.S. Government is subject to restrictions as set forth in subparagraphs (c)(1) and (c) (2) of the Commercial Computer Software - Restricted Rights Clause at FAR 52.227-19.

This manual is protected by copyright, all rights reserved. No part of this book shall be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise without written permission from the Doble Engineering Company.

Doble, the Doble logo, and the M5100 SFRA Instrument are trademarks of Doble Engineering Company.

Microsoft, Windows, Windows95, Windows98 and Windows NT are registered trademarks of Microsoft Corporation in the United States and/or other countries.

LabVIEW is a trademark of the National Instruments Corporation.

Copyright 2002

By Doble Engineering Company

All Rights Reserved

Page 3: SFRA User Guide

WarrantyEquipment Limited Warranty

Doble Engineering Company (DOBLE) warrants the products that it manufactures to be free from defects in material and workmanship for a period of one year from the date shipped from the factory.

During the one year warranty period, DOBLE will repair or replace, at its option, any defective products or components thereof at no additional charge, provided that the product or component is returned, shipping prepaid, to DOBLE. The Purchaser is responsible for insuring any product or component so returned and assumes the risk of loss during shipment. All replaced products and components become the property of DOBLE.

THIS LIMITED WARRANTY DOES NOT EXTEND TO ANY PRODUCTS WHICH HAVE BEEN DAMAGED AS A RESULT OF ACCIDENT, MISUSE, ABUSE, OR AS A RESULT OF MODIFICATION BY ANYONE OTHER THAN DOBLE OR AN AUTHORIZED DOBLE REPRESENTATIVE.

EXCEPT AS EXPRESSLY SET FORTH ABOVE, NO OTHER WARRANTIES, EXPRESSED OR IMPLIED, ARE MADE WITH RESPECT TO THE PRODUCT INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. DOBLE EXPRESSLY DISCLAIMS ALL WARRANTIES NOT STATED HEREIN. IN THE EVENT THE PRODUCT IS NOT FREE FROM DEFECTS AS WARRANTED ABOVE, THE PURCHASER’S SOLE REMEDY SHALL BE REPAIR OR REPLACEMENT AS PROVIDED ABOVE. UNDER NO CIRCUMSTANCES WILL DOBLE BE LIABLE TO THE PURCHASER OR ANY USER FOR ANY DAMAGES, INCLUDING WITHOUT LIMITATION, PERSONAL INJURY OR PROPERTY DAMAGE CAUSED BY THE PRODUCT, ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES, EXPENSES, LOST PROFITS, LOST SAVINGS, OR OTHER DAMAGES ARISING OUT OF THE USE OF OR INABILITY TO USE THIS PRODUCT.

Software Limited Warranty

THIS SOFTWARE PRODUCT IS PROVIDED “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THIS SOFTWARE PRODUCT IS WITH THE PURCHASER SHOULD THE PRODUCT PROVE DEFECTIVE. PURCHASER (AND NOT DOBLE OR AN AUTHORIZED DEALER) ASSUMES THE ENTIRE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.

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Some states do not allow the exclusion of implied warranties, so the above exclusion may not apply. This warranty gives the purchaser specific legal rights and you may also have other rights which vary from state to state.

DOBLE warrants the disks on which the software product is furnished to be free from defects in materials and workmanship under normal use for a period of one hundred and twenty (120) days from the date of shipment from DOBLE.

Limitations of Remedies

DOBLE’s entire liability and Purchaser’s exclusive remedy shall be:

1. The replacement of any disks not meeting DOBLE’S "limited warranty" which are returned to DOBLE.

2. If DOBLE is unable to deliver replacement disks which are free from defects in materials and workmanship, Purchaser may terminate this agreement. By returning the software product and all copies thereof in any form and affirming compliance with this requirement in writing, DOBLE will refund the purchase price.

IN NO EVENT WILL DOBLE BE LIABLE TO PURCHASER FOR ANY DAMAGES, INCLUDING ANY LOST PROFITS, LOST SAVINGS OR OTHER INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE SUCH SOFTWARE PRODUCT, EVEN IF DOBLE OR AN AUTHORIZED DEALER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, OR FOR ANY CLAIM BY ANY OTHER PARTY.

Some states do not allow the limitation or exclusion of liability for incidental or consequential damages, so the above limitation or exclusion may not apply.

For Equipment Maintenance, contact:

Customer Service Manager 617-293-2921Doble Engineering Company85 Walnut StreetWatertown, MA 02472 (USA)

Telephone: 617-926-4900FAX: 617-926-0528Email: [email protected]

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Contents

Preface ............................................................................................................ ixStructure of This Guide........................................................................................................... ixDocument Conventions........................................................................................................... x

1. SFRA Introduction and Theory ..................................................................1-1Introduction ......................................................................................................................... 1-1SFRA Theory ........................................................................................................................ 1-2

2. Getting Started with the M5100 SFRA Instrument ....................................2-1M5100 SFRA Instrument Hardware ...................................................................................... 2-1

Controller ....................................................................................................................... 2-2M5100 SFRA Instrument Accessories .............................................................................. 2-3

3. M5100 SFRA Software ...............................................................................3-1M5100 SFRA Instrument Operating System .......................................................................... 3-1M5100 SFRA Instrument Software ........................................................................................ 3-1

Menu Choices ................................................................................................................ 3-3Test Initiation and Control .............................................................................................. 3-9Test Status .................................................................................................................... 3-10Data Display ................................................................................................................ 3-12

M5100 SFRA Office View Software .................................................................................... 3-18PC Requirements .......................................................................................................... 3-18Installation.................................................................................................................... 3-19

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Contents

4. Setup and Operation ................................................................................. 4-1Safety................................................................................................................................... 4-1

Safety Practices – General Rules..................................................................................... 4-1Grounding...................................................................................................................... 4-2Personnel Safety ............................................................................................................. 4-2

SFRA Test Preparations ........................................................................................................ 4-3Preparing the Transformer .............................................................................................. 4-3Preparing the M5100 SFRA Instrument ........................................................................... 4-3Calibrating ..................................................................................................................... 4-4Creating the Test File...................................................................................................... 4-4Connecting the Apparatus .............................................................................................. 4-6Connection Diagrams..................................................................................................... 4-8

Perform a Test.................................................................................................................... 4-18Initializing the Test ....................................................................................................... 4-18Monitoring Test Status .................................................................................................. 4-20Aborting a Test ............................................................................................................. 4-20

Data Management ............................................................................................................. 4-20Saving Data.................................................................................................................. 4-21Recalling Data.............................................................................................................. 4-22Overlaying Plots........................................................................................................... 4-23Printing ........................................................................................................................ 4-23Powering Down ........................................................................................................... 4-23

5. Data Interpretation ................................................................................... 5-1Frequency-dependant Transformer Equivalent Circuit .......................................................... 5-1Diagnostic Significance of Frequency Ranges ...................................................................... 5-2

Per-phase Measurement ................................................................................................. 5-2Inter-winding Measurement............................................................................................ 5-5

Analysis of Test Data............................................................................................................ 5-8Initial Measurement........................................................................................................ 5-8Subsequent Measurement............................................................................................... 5-8Other Diagnostic Measurements .................................................................................... 5-9

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M5100 SFRA Instrument User’s Guide

Appendix A. Application Tips ....................................................................... A-1Summary of Verifying Functional Operation.........................................................................A-1Cables ..................................................................................................................................A-2

Instrument Setup.............................................................................................................A-4Calibration Test ..............................................................................................................A-4Continuity Test ...............................................................................................................A-5Open Circuit Test ...........................................................................................................A-6

Grounding............................................................................................................................A-7Noise ...................................................................................................................................A-7

Appendix B. M5100 SFRA Instrument Specifications ....................................B-1

Index ..............................................................................................................I-1

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Figures

Figure 1.1 Two-port Network ........................................................................................... 1-3Figure 2.1 M5100 SFRA Instrument Front View................................................................ 2-1Figure 2.2 M5100 SFRA Instrument Controller ................................................................. 2-2Figure 2.3 M5100 SFRA Instrument Specimen Cable and Clamps .................................... 2-4Figure 3.1 M5100 SFRA Instrument Main Screen ............................................................. 3-2Figure 3.2 File Menu ........................................................................................................ 3-4Figure 3.3 Open File Dialog Box...................................................................................... 3-4Figure 3.4 Save File Dialog Box ....................................................................................... 3-5Figure 3.5 Select Bands Choice Box ................................................................................. 3-6Figure 3.6 Clear Graph Dialog Box .................................................................................. 3-7Figure 3.7 Start and Abort Controls .................................................................................. 3-9Figure 3.8 Start Test Dialog Box ....................................................................................... 3-9Figure 3.9 Trigger Status Measurement OK..................................................................... 3-10Figure 3.10 Trigger Status No Trigger ............................................................................... 3-10Figure 3.11 Nameplate Screen ......................................................................................... 3-13Figure 3.12 Display Band Selection Box........................................................................... 3-15Figure 3.13 Graph Palette ................................................................................................ 3-15Figure 3.14 Plot Legend with Plot Names......................................................................... 3-17Figure 3.15 Plot Legend Right-click Menu Bar.................................................................. 3-17Figure 3.16 Select Installation Type.................................................................................. 3-19Figure 3.17 Choose SFRA Directory ................................................................................. 3-20Figure 3.18 M5100 SFRA Software Installation Complete................................................. 3-20Figure 4.1 M5100 SFRA Initial Screen .............................................................................. 4-4Figure 4.2 Nameplate Screen ........................................................................................... 4-5Figure 4.3 Chassis Ground Cable Wiring.......................................................................... 4-6Figure 4.4 Cable Connections .......................................................................................... 4-7Figure 4.5 M5100 SFRA Instrument Run Screen ............................................................. 4-18Figure 4.6 M5100 SFRA Instrument Run Dialog Box ...................................................... 4-19Figure 4.7 Save Dialog Box ............................................................................................ 4-21Figure 4.8 Open File Dialog Box.................................................................................... 4-22Figure 5.1 Per-Phase Measurement – Magnitude of the Transfer Function ........................ 5-3

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Figures

Figure 5.2 Per-Phase Measurement – Phase of the Transfer Function ............................... 5-4Figure 5.3 Inter-Winding Measurement – Magnitude of the Transfer Function ................. 5-6Figure 5.4 Inter-Winding Measurement – Phase of the Transfer Function ......................... 5-7Figure A.1 High Frequency Effects on Cables ................................................................... A-3Figure A.2 High Frequency Effects on Noise..................................................................... A-8

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Tables

Table 5.1 Power Transformer Failure Modes and Diagnostic Measurements ................... 5-9Table B.1 Controller ........................................................................................................B-1Table B.2 Analog Source .................................................................................................B-1Table B.3 Analog Inputs ..................................................................................................B-2Table B.4 M5100 SFRA Software .....................................................................................B-2Table B.5 Data Collection ...............................................................................................B-2Table B.6 Data Display ...................................................................................................B-3Table B.7 Physical ...........................................................................................................B-3Table B.8 Environmental .................................................................................................B-4

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viii 72A-1849-01 Rev. B 6/02

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Preface

Structure of This GuideThis guide consists of five chapters, two appendices and an index.

Chapter 1 ”SFRA Introduction and Theory”

Describes the method of Sweep Frequency Response testing.

Chapter 2 ”Getting Started with the M5100 SFRA Instrument”

Gives an overview of the M5100 SFRA Instrument and its associated accessories.

Chapter 3 ”M5100 SFRA Software”

Explains the features and functions of the M5100 SFRA software, as well as describing the requirements and installation for use on a PC.

Chapter 4 ”Setup and Operation”

Provides a detailed description on setting up the test set, preparing the transformer for tests, test connections, and obtaining results. Basically a start-to-finish list of instructions for a crew planning to do SFRA testing.

Chapter 5 ”Data Interpretation”

Explains how to analyze the data once the testing is complete.

Appendix A ”Application Tips”

Discusses the role of cable impedance, grounding and noise in instrument operation.

Appendix B ”M5100 SFRA Instrument Specifications”

Lists the physical and environmental specifications for the instrument.

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Document Conventions

Document ConventionsButtons, Picklist Items, Menu Items, etc.

Items that are selected by the user – buttons, menu items, etc. – are shown in this text.

Windows Windows referenced in the text are shown in this text.

User-entered text Text entered into M5100 fields is shown in this text.

Field Names/Displayed text

Messages displayed on windows and field names are shown in this text.

NOTE The Note icon signifies information that is important to the user.

WARNING The WARNING icon signifies information that is necessary in order to properly perform a function. Failure to follow information contained in warnings could cause a hazardous condition.

x 72A-1849-01 Rev. B 06/02

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1. SFRA Introduction and Theory

IntroductionSweep Frequency Response Analysis (SFRA) testing has become a valuable tool for verifying the geometric integrity of electrical apparatus, especially transformers. The SFRA technique provides internal diagnostic information using non-intrusive procedures. Over the last ten years, the SFRA test method has been proven to provide accurate and repeatable measurements.

Power transformers are specified to withstand the mechanical forces arising from both shipping and subsequent in-service events, such as faults and lightning. Transportation damage can occur if the clamping and restraints are inadequate; such damage may lead to core and winding movement. The most severe in-service forces arise from system faults, and are axial and radial in nature. If the forces are excessive, radial buckling or axial deformation can occur. With a core form design the principal forces are radially directed, whereas in a shell form unit they are axially directed, and this difference is likely to influence the types of damage found.

Once a transformer has been damaged, even if only slightly, the ability to withstand further short circuits is reduced. Utility personnel need to effectively identify such damage. A visual inspection is costly and does not always produce the desired results or the correct conclusion. During a field inspection, the oil has to be drained and confined entry rules apply. Since so little of the winding is visible, little damage is seen other than displaced support blocks. Often, a complete tear down is required to identify the problem. An alternative method is to implement field-diagnostic techniques capable of detecting damage.

There is a direct relationship between the geometric configuration and the distributed electrical elements, otherwise known as RLC networks, of a winding and core assembly. This RLC network can be identified by its frequency-dependent transfer function. Frequency Response Analysis testing can be accomplished by the sweep frequency method (SFRA). Changes in the geometric configuration alter the impedance network, and in turn alter the transfer function. Changes in the transfer function will reveal a wide range of failure modes.

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SFRA Theory

SFRA TheoryThe primary objective of SFRA is to determine how the impedance of a test specimen behaves over a specified range of frequencies. The impedance is a distributive network of real and reactive electrical components. The components are passive in nature, and can be modeled by resistors, inductors, and capacitors. The reactive properties of a given test specimen are dependent upon and sensitive to changes in frequency. The change in impedance versus frequency can be dramatic in many cases. This behavior becomes apparent when we model the impedance as a function of frequency. The result is a transfer function representation of the RLC network in the frequency domain.

Frequency response analysis is generally applied to a complex network of passive elements. For practical purposes, we will only consider resistors, inductors, and capacitors as passive circuit elements, and they are assumed to be ideal. These three fundamental elements are the building blocks for various physical devices, such as transformers, motors, generators, and other electrical apparatus.

It is important to understand the difference between the physical device and the mathematical model we intend to use. When large and complex systems are electrically analyzed, we are often faced with a poorly defined distributed network. A distributed network contains an infinite amount of infinitely small RLC elements. For example, transmission lines are generally distributed in nature. It is practical to model such distributed systems by lumping the basic RLC components together, resulting in a lumped network. Lumping elements together for a single frequency is a trivial task, however, when system modeling requires spanning over a significant frequency interval, then producing a suitable lumped model becomes difficult.

When a transformer is subjected to SFRA testing, the leads are configured in such a manner that four terminals are used. These four terminals can be divided into two unique pairs, one pair each for the input and the output. These terminals can be modeled in a two-terminal pair or a two-port network configuration. Figure 1.1 illustrates a two-port network.

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M5100 SFRA Instrument User’s Guide

Figure 1.1 Two-port Network

The impedances, Z11, Z22, Z12, and Z21, are formed by solving for the open-circuit impedance for each lumped element. It should be noted that the negative terminals are short-circuited when transformers are tested. The transformer tank is common for both negative or lower terminals. The transformer tank and lead ground shields must be connected together to achieve a common-mode measurement. This assures that no external impedance is measured. Applying the connection in this manner helps reduce the effects of noise. It is very important to obtain a zero impedance between the lower or negative terminals to assure a repeatable measurement.

The transfer function of an RLC network is the ratio of the output and input frequency responses when the initial conditions of the network are zero. Both magnitude and the phase relationships can be extracted from the transfer function. The transfer function helps us better understand the input/output relationship of a linear network. The transfer function also represents the fundamental characteristics of a network, and is a useful tool in modeling such a system. The transfer function is represented in the frequency domain and is denoted by the Fourier variable H(jω), where (jω) denotes the presence of a frequency dependent function, and ω = 2πf. The Fourier relationship for the input/output transfer function is given by:

When a transfer function is reduced to its simplest form, it generates a ratio of two polynomials. The main characteristics, such as half-power and resonance, of a transfer function occur at the roots of the polynomials.

( ) ( )( )ω

ωω

jVjV

jHinput

output=

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SFRA Theory

The goal of SFRA is to measure the impedance model of the test specimen. When we measure the transfer function H(jω), it does not isolate the true specimen impedance Z(jω). The true specimen impedance Z(jω) is the RLC network, which is positioned between the instrument leads, and it does not include any impedance supplied by the test instrument. It must be noted that when using the voltage relationship, H(jω) is not always directly related to Z(jω). For Z(jω) to be directly related to H(jω), a current must be substituted for the output voltage and then Ohms Law can be realized. However, SFRA uses the voltage ratio relationship for determining H(jω). Since the SFRA test method uses a 50 Ohm impedance match measuring system, the 50 Ohm impedance must be incorporated into H(jω). The next equation shows the relationship of Z(jω) to H(jω):

Often it is useful to plot the magnitude and phase relationship of the transfer function in logarithmic format. The units of magnitude and phase are in the decibels (dB) and degrees, respectively. The magnitude and phase is represented as follows:

This format takes advantage of the asymptotic symmetry by using a logarithmic scale for frequency. Plotting the phase relationship with the magnitude data will help determine whether the system is resistive, inductive, or capacitive. It is often useful to compare resonance in the magnitude plots with the zero crossings in the phase relationship.

( ) ( ) 5050

+==

ωω

jZVV

jHinput

output

( )( ))(tan)(

)(log20)(1

10

ωθω

jHAjHdBA

−=

=

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2. Getting Started with the M5100 SFRA Instrument

The M5100 SFRA Instrument comes complete with packaged hardware, software, and cables. This chapter provides an introduction to the various parts and accessories that comprise the M5100 SFRA Instrument.

M5100 SFRA Instrument HardwareThe M5100 SFRA Instrument measures and records the frequency response characteristics of transformer windings. It accomplishes this using the various hardware components packaged in a rugged field instrument. The primary hardware components are a CPU controller, an excitation source, and a measurement module. The M5100 SFRA Instrument is also outfitted with an integrated keyboard and color screen (Figure 2.1).

Figure 2.1 M5100 SFRA Instrument Front View

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Controller

ControllerThe M5100 SFRA Instrument is outfitted with various indicators, ports and connections (Figure 2.2).

Figure 2.2 M5100 SFRA Instrument Controller

External

Network Port

Power On

CPU Status LEDS

Printer Port

Test Lead

Ground

Power On

USB Ports

Intensity Control

Power Indicator

Keyboardand Mouse

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M5100 SFRA Instrument User’s Guide

M5100 SFRA Instrument Accessories

Cables The test leads are made from low loss RG-58 RF coaxial cable with the shields grounded to the instrument chassis through a standard connector. The M5100 SFRA Instrument requires a matched impedance signal cable, and performs a single end measurement, that is, the signal is measured with respect to the instrument ground. The shield of the signal cable must be connected to the chassis using a 50 Ohm impedance-matched RF BCN connector. Practical field experience dictates the lead be 60 ft. in length. This length is the shortest length useful to test the largest transformers from a location on the ground, adjacent to the unit. Nevertheless, it is the lead length that determines the maximum effective frequency.

NOTE The cables and connectors supplied with the instrument should not be modified in any manner.

Test lead connectors are large enough to clamp directly onto the bushing terminals and will form a good connection.

Grounds Grounding of signal cable shields, specimen, and instrument chassis is important to achieving a reproducible result. Two grounding components are provided with the M5100 SFRA Instrument:

• Cable Shield Grounds - used to connect cable shield to the transformer ground. These ground connections are located 12 ft. back from the terminal connection on the measurement ends of the cables.

• Instrument Chassis Ground - used to connect the instrument chassis to the ground plate of the transformer (Figure 2.3).

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M5100 SFRA Instrument Accessories

Figure 2.3 M5100 SFRA Instrument Specimen Cable and Clamps

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3. M5100 SFRA Software

This chapter discusses the installation and operation of the M5100 SFRA software including:

• M5100 SFRA Operating System• M5100 SFRA Instrument Software• M5100 SFRA Office View Software

M5100 SFRA Instrument Operating SystemThe M5100 SFRA Instrument comes with Microsoft Windows 2000® installed.

M5100 SFRA Instrument SoftwareThis section discusses the various components of the M5100 SFRA software including the:

• Menu Choices• Test Initiation and Control• Test Status• Data Display

The M5100 SFRA software operates from the main instrument screen and automatically starts when the instrument is started. This screen is shown in Figure 3.1 with call outs to its components.

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M5100 SFRA Instrument Software

Figure 3.1 M5100 SFRA Instrument Main Screen

The M5100 SFRA Instrument main screen has four primary functions:

1. The menu bar contains the following:

• File• Select Bands• Clear Graph• Analysis Mode• Frequency Scale• Calibrate• Help (not available through this function)

These items provide access to data management and instrument configuration.

2. Test Initiation and Control consists of START and ABORT. These buttons start and stop the collection of data.

PlotLegend

Test Status

Test Initiationand Control

Main Menu

GraphPalette

CursorLocations

Lock to PlotBring to Center

CursorSelection

GraphicalView Tabs

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M5100 SFRA Instrument User’s Guide

3. Test Status displays several operational parameters while the instrument is running including:

• Current Frequency• Magnitude (Response)• Drive Amplitude• Vertical Range• Autorange• Clipping

The Trigger Status indicator displays any relevant error messages, and tracks the percentage to test completion in bar graph form.

4. Data Display shows all collected and entered data. This area consists of five plotting screens and one tabular screen, which are selected by clicking the corresponding tab. The tab choices are:

• Magnitude*• Phase*• Waveform*• Sub Band Magnitude• Sub Band Phase• Nameplate

*Zoom, cursor, and scaling controls are accessed in these tabs, as well as trace properties, such as color and line style.

Menu ChoicesMenu choices provide access to data management routines such as recalling data and saving data, while other menu choices are used to configure the operation of the instrument. The menu choices are:

• File• Select Bands• Clear Graph• Analysis Mode • Frequency Scale• Calibrate• Help (not available through this function)

NOTE The Menu Choices can be accessed by shortcut keys. The ALT key in combination with the corresponding underlined letter selects the desired menu choice.

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Menu Choices

File The File pull-down menu includes Recall Data, Save Data, Print Screen, and Quit Program (Figure 3.2).

Figure 3.2 File Menu

Recall Data Select Recall Data and the Open File window appears (Figure 3.3). This window is used to browse for the desired files.

Figure 3.3 Open File Dialog Box

Stored data is recalled using the Recall Data function. Data can be recalled in parts or as a whole. Recalling data in parts allows data from different sources to be viewed, overlaid, and combined. Data is stored in an ASCII delimited format specific to the M5100 SFRA Instrument and is designated with a .csv extension. The M5100 SFRA Instrument is capable of having up to 9 traces open simultaneously for viewing, overlaying and saving.

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M5100 SFRA Instrument User’s Guide

Overlaying traces from different test dates is useful in comparing newly acquired data to historical data. Data from similar units can also be overlaid. Because data from multiple units can be overlaid, multiple nameplates can be recalled and saved together, however only one nameplate can be viewed at a time.

Save Data Select Save Data and the Save File window appears (Figure 3.4). This window is used to browse for the desired location to save files.

Figure 3.4 Save File Dialog Box

The M5100 SFRA software automatically generates a filename from field information stored in the nameplate. However, once prompted to save the file, any filename can be entered. It is recommended that the filename be related to its test specimen.

Print Screen Select Print Screen to print the current plot in portrait to the active printer. One plot is printed per page and the filename is appended to the top of the printed page. The plot, grid, and legend colors are inverted to minimize printer resources.

Quit Program Select Quit Program or click the in the upper right-hand corner of the M5100 SFRA software screen to exit. If data has not been saved, a dialog box provides the option to save the data.

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Menu Choices

Select Bands Select Select Bands to enter the test frequency range or so called frequency bands. Select Bands can be used at any time, except when the M5100 SFRA Instrument is collecting data. The M5100 SFRA Instrument is limited to a specified test frequency while plotting the transfer function of a given specimen. Figure 3.5 shows the choice box used for selecting various test frequency bands.

Figure 3.5 Select Bands Choice Box

The choice box provides five selections; the default is 20 Hz to 2 MHz. Application experience dictates that this default is the most practical. The choice box allows multiple selections. If more than one check mark exists, then the software uses the lowest and highest frequency from all bands selected to determine an overall frequency band.

Example: If the following test frequency bands are selected:

• 20 Hz to 20 kHz• 200 Hz to 200 kHz

The M5100 SFRA Instrument will limit the test frequency range to 20 Hz to 200 kHz.

Click DONE to finalize the settings.

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Clear Graph Click Clear Graph and Figure 3.6 appears. This dialog box is used to clear plots and nameplates. Plots can be cleared one at a time or in groups.

NOTE Once a plot is cleared it is deleted from memory.

Figure 3.6 Clear Graph Dialog Box

Plots can be cleared one at time or the SHIFT key can be used to select any combination of plots to be cleared. As plots are selected for clearing, they are highlighted.

Data, including plots and nameplates, can be cleared in one of three ways:

• Click Clear Selected Plots Only to delete all selected plots from memory.

• Click Clear All Plots to delete all active plots listed in the left-hand plot queue.

• Click Clear All Plots and Nameplate Data to delete all active plots listed in the left-hand plot queue and any associated nameplate data.

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Menu Choices

Analysis Mode Select Analysis Mode to access its pull-down menu which includes:

• RMS• Peak

These two choices present different methods for scaling waveforms. The RMS value represents the effective energy in the waveform, while the Peak represents the peak magnitude. Either method produces the same transfer function. These choices can be selected at any time, even while the test set is collecting data.

Frequency Scale Select Frequency Scale to access its pull-down menu which includes:

• Log• Linear

This function configures the x-axis scaling. The x-axis can be scaled in either a logarithmic or linear format.

Calibrate Select Calibrate to calibrate the instrument.

To provide the maximum accuracy, independent of temperature change and environmental conditions, the M5100 SFRA Instrument needs to be recalibrated periodically or as a function of environmental changes. Selecting Calibrate produces a prompt requesting continuation or cancellation. The prompt also requests that the unit be switched on for at least 15 minutes prior to calibration and that all leads connected to the M5100 SFRA Instrument be disconnected, with the exception of the safety ground and power cable.

NOTE Failure to properly disconnect leads may cause improper calibration. The calibration process takes roughly 2 minutes.

During calibration, the M5100 SFRA software performs the following operations:

• Gain and offset are calibrated for each individual input range.• AC flatness is calibrated over the entire bandwidth to be within

specified tolerances.• Analog trigger levels are calibrated.• The time-to-digital converter is calibrated.

Help Help is not supported in this release.

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Test Initiation and ControlTest Initiation and Control consists of Start Test and Abort Test (Figure 3.7).

Figure 3.7 Start and Abort Controls

Start Test Click Start Test to start a test (or press the F1 function key). Once Start Test is clicked the plot list dialog box shown in Figure 3.8 appears.

Figure 3.8 Start Test Dialog Box

Any of the nine available plots can be selected by clicking or scrolling on the plot list. No specific plot or test order is required. However, as tests are completed, the plots that have been used become inactive, and the software grays-out these choices. Once the desired plot name is selected, clicking on Start initiates the test.

Click Cancel to return to the main screen without starting the test.

NOTE Using the Clear Graph function on the menu bar to delete any unwanted plots reactivates those positions on the plot list. The Clear Graph function deletes the data associated with that plot.

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Test Status

Abort Test Click Abort Test to abort a test (or press the F2 function key).

The Abort Test function only affects the active trace; previous data traces are not lost. Once a test is aborted, two options exist:

• Keep all data associated with the aborted trace.• Disregard and delete all data associated with the aborted trace.

NOTE The software saves these incomplete traces as if they are normal, so they can be recalled in the future. If the aborted test has no value, then it should be disregarded. If the data is disregarded, then only the data associated with the specific trace is deleted. All data on the screen prior to the aborted test is unaffected.

Test StatusThe Test Status displays several operational parameters while the instrument is running, including:

• Trigger Status• Test Status• Current Frequency• Magnitude (Response)• Drive Amplitude• Vertical Range• Autorange• Clipping

Trigger Status The Trigger Status indicator has two states (Figure 3.9 and Figure 3.10).

Figure 3.9 Trigger Status Measurement OK

Figure 3.10 Trigger Status No Trigger

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If the M5100 SFRA Instrument is actively collecting data, the Trigger Status provides the Measurement OK message. The Trigger Status indicates No Trigger if the instrument does not detect the excitation source. If No Trigger is detected, the instrument continues to run until the source is re-established or the test is aborted. Improperly placed leads can cause the No Trigger message.

Test Status Indicator The Test Status indicator produces a visual representation of the test progress. A horizontal bar graph indicates the percentage to completion for the test. The following operation labels appear while the M5100 SFRA Instrument is running:

• TEST RUNNING• TEST COMPLETED• TEST ABORTED

A typical test scan takes roughly four minutes.

Current Frequency As the M5100 SFRA Instrument collects data, the active or Current Frequency is displayed. This value is bound between 10 Hz and 10 MHz and increments quickly during a test.

Response As the M5100 SFRA Instrument collects data, the Response associated with the Current Frequency is displayed. This value is expected to be zero or negative and is in decibels (dB).

Drive Amplitude The Drive Amplitude is the active level of the excitation source. The arbitrary generator can provide up to 10 V when placed across a high impedance. The arbitrary generator lowers its output when it experiences lower impedances. The arbitrary generator output level varies depending on the impedance of the specimen. It varies between 10 V for high impedance specimens and 5 V for low impedance specimens.

Vertical Range For the M5100 SFRA Instrument to be accurate, it scales the inputs as the signal level changes. The Vertical Range changes with signal level and indicates the present measuring range being used. The M5100 SFRA Instrument automatically sets the Vertical Range. The range is set from 10.00 V to 25 mV in 10% increments, depending on the signal level being measured. As the magnitude plot becomes more attenuated the Vertical Range is expected to decrease. The Vertical Range is a good indicator of the signal level being measured.

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Data Display

Autorange As the signal level changes, the Vertical Range is expected to follow. The Autorange indicates any change in the Vertical Range. Autorange is a green light indicator that illuminates bright green when the active Vertical Range changes. When no change takes place between discrete measurements the Autorange indicator remains dark.

Clipping Clipping indicates that one of the M5100 SFRA Instrument inputs exceeds a voltage level greater than the maximum input level. Clipping can cause incorrect measurements. Clipping can be caused by external energy injection or possibly by the passive component properties of the test specimen. In most test cases, assuming the specimen is isolated and free from any interference, clipping won’t occur. The clipping indicator illuminates bright red if clipping is present.

Data DisplayAll collected data, whether it be magnitude or phase traces or nameplate data, is displayed in this area. The Data Display consists of five plotting screens and one tabular screen, which are selected using the corresponding tabs.

Magnitude The Magnitude plot displays the voltage in/voltage out relationship of the two measured waveforms. Up to nine plots can be displayed at one time. The X-axis is scaled in frequency (Hz), and the Y-axis is scaled in decibels (dB).

Phase The Phase plot displays the phase shift relationship of the two measured waveforms. Up to 9 plots can be displayed at one time. The X-axis is scaled in frequency (Hz), and the Y-axis is scaled in degrees.

Waveform The Waveform plot is only active while a test is running and measures the actual reference and measured waveforms. These two waveforms do not provide any diagnostic information for the apparatus being tested, however they can be used to verify the quality and integrity of the test signals. The Waveform plot can be very useful in visually identifying any interference issues that may exist.

Sub Band Magnitude

The Sub Band Magnitude provides three separate scaled plots, which are derived from the main Magnitude plot. These plots represent various frequency ranges from low to high, where the top plot represents the lower frequency range and bottom plot represents the higher frequency range.

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The Sub Band Magnitude plots are scaled by the following frequency ranges:

• 20 Hz to 20 kHz• 200 Hz to 200 kHz• 2 kHz to 2 MHz

Sub Band Phase Similar to the Sub Band Magnitude plots, Sub Band Phase also provides three separate scaled plots, however they are derived from the main Phase plot. They share the same frequency scaled range as the Sub Band Magnitude plots.

Nameplate

Figure 3.11 Nameplate Screen

Several fields are available for identifying the test specimen (Figure 3.11). These fields either require text entries or entries from the pull-down menus.

DETC This represents the position of the no-load tap changer. Typical values for the DETC are:

• 1, 2, 3, 4, 5• A, B, C, D, E

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Data Display

LTC This represents the position of the load tap changer. Typical values for the LTC are:

• 16R, 15R, 14R, … 1R, N, 1L, … 14L, 15L, 16L

Nameplate to Edit/View

More than one nameplate can be associated with one data file. This is useful for saving overlaid data from different test specimens. The Nameplate to Edit/View pull-down menu allows the user to choose between all available nameplates for a given test specimen.

It is in the Nameplate display where the plot names can be edited. Any changes to the plot names are carried through to all plots.

As the Nameplate information is entered the M5100 SFRA software automatically generates a filename. This is the filename that is saved when Save is selected. Five fields are used to generate the filename. As these fields are entered, they are appended together:

• Company• Location• Manufacturer• Serial Number• Test Date

Add New Nameplate Record/Delete This Template

Click Add New Nameplate Record or Delete This Nameplate Record to add a new nameplate or delete the current nameplate, respectively.

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Add Date & TimeClick Insert Date & Time to automatically add the date and time. These entries are obtained from the settings found in the Microsoft Windows 2000 operating system. This function is only available on the instrument software and is not found on M5100 SFRA Office View Software version.

Display Band The Display Band selection box offers a short cut to scaling the X-axis. Figure 3.12 shows the available scaling options offered by Display Band.

Figure 3.12 Display Band Selection Box

Display Band offers a selection labeled User Defined, which allows the user to set the X-axis minimum and maximum. Once the User Defined option is selected, the plot minimum and maximum can be edited directly on the plot. These values can be entered in one of three formats, numeric, engineering, or scientific. For example, the numeric value 1000 could also be represented by the engineering format 1k or scientific format 1e3.

Graph Palette The Graph Palette (Figure 3.13) has three buttons: Zoom, Cursor Movement, and Pan.

Figure 3.13 Graph Palette

Zoom

Pan

CursorMovement

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Data Display

Zoom Tool Click the Zoom tool and the Zoom palette appears. The Zoom palette contains the following operations:

Cursor Movement Tool

Use the Cursor Movement tool to move the cursor on the graph.

Pan Use the Pan tool to pick up the plot and move it around on the display.

Cursors Two cursors are available and their controls are located to the right of the plot screen. Either cursor can be turned on or off. A display below the plot screen indicates the cursor position. Features such as lock to plot and bring to center are available. Located near the cursor control are two fields labeled Frequency Delta and Magnitude Delta. These two values return the difference between the cursor for both axes when both cursors are active.

Use the Zoom Ring to zoom in and out on the display. The Zoom Ring provides the following options, clockwise from the top left, to zoom in and out of the graph:

Use Zoom to Rectangle and click a point on the display as a corner of the zoom area and drag the tool until the rectangle covers the zoom area.Use X-zoom to zoom in on an area of the graph along the x-axis.

Use Y-zoom to zoom in on an area of the graph along the y-axis.

Use Zoom In and click a point you want to zoom in on. Hold down the Shift key to switch between Zoom In about Point and Zoom Out about Point.Use Zoom Out and click a point to zoom in to

Auto Scale Use this option to return to the original view.

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Plot Legend The Plot Legend provides identification for each plot and allows the plots to be configured for preference, such as color, line style, and line width. Figure 3.14 shows the Plot Legend and Figure 3.15 shows the Plot Legend right-click menu bar.

Figure 3.14 Plot Legend with Plot Names

Figure 3.15 Plot Legend Right-click Menu Bar

The plot names are matched to corresponding line styles. The menu box is accessed by right-clicking on a specific plot name. Various plot style parameters are configured from this menu.

Common Plots Provides various common plot options, such as line, points, or both.

Color Lets you choose the plot color from the color palette.

Line Style Provides various solid and dashed line styles.

Line Width Provides various line widths.

Anti-Aliased Provides a choice to make line plots appear smoother without changing the data.

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Bar Plots Provides various bar plot options.

Fill Base Line Provides the ability to fill specific regions around a given plot or between two plots. Filling the area between two plots can provide a better visualization of difference and error.

Interpolation Provides various interpolation options, including plotting just data points. Interpolation style of the plots are none, stepwise, linear, stepwise horizontal, stepwise horizontally centered, or stepwise vertically centered.

Point Style Provides the point style of various types that can be plotted. Sixteen point styles are available and are displayed in the shortcut menu by selected Point Style.

X Scale Sets the index of X scale with which this plot is associated.

Y Scale Sets the index of Y scale with which this plot is associated.

M5100 SFRA Office View SoftwareThe M5100 SFRA software can also be installed on a PC for the purpose of viewing previously recorded test data. The M5100 SFRA Instrument is a standalone unit and cannot be controlled from a PC or laptop. The software used for PC purposes is essentially the same software installed on the M5100 SFRA Instrument with the exception that the PC software does not have any of the hardware drivers necessary to operate the M5100 SFRA Instrument.

PC RequirementsPC/laptop minimum requirements are:

• IBM PC compatible, Pentium

• Windows“ 98 or later, Windows NT 4.X or later; or Windows 2000. For the Windows NT 4X operating system, it should have Service Pack 4 (SP4) or higher installed.

• 32 MB RAM minimum• 20 MB disk space to install

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InstallationThe M5100 SFRA software has two versions, one that is pre-installed on the instrument and the other that is used to view results on other PCs. The M5100 SFRA installation program installs the M5100 SFRA software first and then installs LabVIEW.

To install the M5100 SFRA software:

1. Insert the CD into the drive.

The autorun program presents the window shown in Figure 3.16.

Figure 3.16 Select Installation Type

2. Click the checkbox next to M5100 SFRA Office View Software to install the PC-based version of the software.

3. Click Continue.

A window appears for choosing the target directory (Figure 3.17).

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Figure 3.17 Choose SFRA Directory

NOTE To change the target directory click Browse. Select the new target directory and click Next.

A dialog box appears (Figure 3.18 on page 3-20) indicating the successful installation of the M5100 SFRA Office View software.

4. Click Finish to complete the process.

Figure 3.18 M5100 SFRA Software Installation Complete

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4. Setup and Operation

SafetySafety cannot be overemphasized when working on or around high voltage electrical apparatus. Companies that generate, transmit, distribute, or utilize high voltage electricity should, and do, have precise rules for safe practices and procedures for personnel whose working responsibilities involve testing and maintenance of the various types of high voltage apparatus, and their associated lines, cables and conductors, as well as the associated accessories.

Safety Practices – General RulesThe transformer under test should be completely de-energized and isolated from the power system before performing any SFRA tests using the M5100 SFRA Instrument.

The method of testing a high voltage apparatus (transformer) involves exciting the apparatus with the M5100 SFRA Instrument. Care must be taken to avoid contact with the apparatus being tested, its associated bushing and conductors, and with the M5100 SFRA Instrument cables and connectors.

The test crew must make a visual check to ensure that the apparatus terminals are isolated from the power system. Because the apparatus under test may fail, precautions (such as barriers or entrance restrictions to the test area) must be taken to avoid harm in the event of a violent failure.

All of your company rules for safe practice in testing must be strictly conformed to, including all practices for tagging and isolating apparatus during testing and maintenance work. State, local, and federal regulations, e.g., OSHA, may also apply.

NOTE Company rules and government regulations take precedence over Doble recommendations.

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Grounding

GroundingThe apparatus under test, its tank or housing, and the M5100 SFRA Instrument must be solidly and commonly grounded or earthed. This also applies to any mobile equipment being tested.

The M5100 SFRA Instrument test cable shields must also be grounded or earthed to the same common point as the instrument.

CAUTION Proper grounding techniques are a very important step in safety and in ensuring reliable SFRA test results.

Personnel SafetyA pretest tailgate meeting is recommended. Frequently, other crews will be working on non-test related tasks in close proximity to equipment being tested. The tailgate meeting should include all personnel who will be working in proximity to the area where testing will be performed. In this meeting, the tests to be performed, the apparatus and the voltage test levels involved, potential hazards involved with the work, and the individual assignments should all be reviewed with the crew members. Test personnel need to remain aware of the work activity taking place around them and alert to the possibility that non-test personnel may enter the test area.

A consistent and uniform set of signals, both visual and verbal, should be agreed upon, and should be followed by all of the crew members during testing.

While making the various types of connections involved in the tests, it may be necessary for personnel to climb up on the apparatus, but no one should remain on the apparatus during the test itself.

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SFRA Test PreparationsSFRA test preparations consist of:

• Preparing the Transformer• Preparing the M5100 SFRA Instrument• Calibrating• Creating the Test File• Connecting the Apparatus

Preparing the TransformerThe transformer to be tested must be completely isolated from the power system. This requires that all bushings of all windings be disconnected from any bus and insulators. This ensures that the measurements performed are not adversely affected by interference. It is desired to measure only the RLC network of the transformer.

In order to maintain consistency and repeatability of measurements, all terminals that are not under test should be isolated and floating. A frequency response could be measured with the remaining terminals grounded, however it could not be compared to a response that was measured with floating terminals since a different RLC response would be measured.

NOTE It is Doble Engineering’s recommended procedure to measure the response with all remaining terminals isolated and floating.

Preparing the M5100 SFRA Instrument• Turn on the power switch located on the back of the M5100 SFRA

Instrument.

The M5100 SFRA software should automatically launch from the desktop.

If not, to initiate the program:

• Double-click on the M5100 SFRA icon or go to START, PROGRAMS, DOBLE M5100, M5100 v.1.1 to open the software.

Wait for the main testing screen to appear. The Magnitude tab should be highlighted (Figure 4.1 on page 4-4).

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Calibrating

Figure 4.1 M5100 SFRA Initial Screen

CalibratingBefore performing any SFRA testing, a calibration must be performed on the instrument after it has been on for approximately 15 minutes. The calibration routine needs to be performed only once for any particular testing session, not before each individual test.

For more information regarding calibration of the M5100 SFRA Instrument, refer to the Calibrate section in Chapter 3 ”M5100 SFRA Software”.

Creating the Test File1. Click on the Nameplate tab to bring up the transformer’s nameplate

information (Figure 4.2).

General nameplate data is entered here. The filename to save results is created in the Nameplate to View/Edit field by automatically using the key nameplate fields (company name, location, mfr., serial number and date). It is not necessary to fill in all of these key fields in order to save the data file, however it is highly recommended.

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2. Enter all appropriate nameplate information. Any fields which have a pull-down list have a down arrow. These include: mfr., reason, # windings, # phases, winding config., MVA/KVA).

3. Enter Plot Names for all appropriate test connections to be performed. To fill in the test connection, simply click on the first plot name. It is highlighted. The unused designation is deleted when the new connection is filled in.

Once the Plot Names are filled in, the screen is complete. A completed nameplate screen is shown in Figure 4.2.

NOTE The actual test connections are dependent upon the configuration of the transformer under test.

Figure 4.2 Nameplate Screen

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Connecting the Apparatus

Connecting the ApparatusThe M5100 SFRA Instrument is equipped with a signal cable, response cable, and a ground cable.

To perform apparatus connections:

1. Attach the 30’ chassis ground cable clamp to the grounding plate on the transformer and insert the cam-lock connector into the instrument, twisting in a clockwise rotation to insure locking of the connection. Gently attempt to pull this connection straight out to verify the locking has occurred (Figure 4.3).

Figure 4.3 Chassis Ground Cable Wiring

2. Attach the signal and response cables to the instrument and then to the appropriate bushings.

Use the diagrams starting in ”Connection Diagrams” on page 4-8 to assist in wiring.

3. Connect the color coded cables to the M5100 SFRA instrument by matching the corresponding BNC connector (Figure 4.4).

Yellow Excitation Source Cable

Black Measurement Cable

Red Reference Cable

Instrument Connection Grounding Plate Connection

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4. Connect the main cable clamps, red and black, to the bushing terminals of interest. Also, connect the ground clips for each cable, red and black, to the corresponding bushing flange.

NOTE Remember, proper grounding techniques ensure reliable test data.

Figure 4.4 Cable Connections

NOTE To minimize the chance of the conductors becoming energized due to static electricity, Doble Engineering Company recommends attaching all test set leads to the instrument while the other end of the leads are still on the ground. Attaching the leads to the transformer bushings first increases the risk of operator injury.

NOTE All three connectors on the M5100 SFRA Instrument have colored dots indicating where like colored leads are connected. Connectors with no markings should not have cables connected to them.

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Connection Diagrams

Connection Diagrams

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Connection Diagrams

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Connection Diagrams

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Connection Diagrams

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Connection Diagrams

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Perform a Test

Perform a TestVarious tasks are encountered when running a test with the M5100 SFRA Instrument. These include:

• Initializing the Test• Monitoring Test Status• Aborting a Test

Initializing the TestTo perform a test:

1. Select the Magnitude tab. At this point the graphical display resembles Figure 4.5.

Figure 4.5 M5100 SFRA Instrument Run Screen

Notice that the test connections (top right) are now listed as they were entered under the Nameplate tab. Each of the connections is color-coded for easy identification of the traces during testing and overlay.

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2. Verify the connection of the M5100 SFRA Instrument cables to the first desired test connection.

In Figure 4.5 the signal cable (yellow) should be connected to the H1 bushing terminal, and the response cable (black) should be connected to the H2 bushing terminal.

3. Verify that the M5100 SFRA Instrument cable shield wire and the M5100 SFRA Instrument chassis are both grounded solidly to the transformer tank ground.

4. Click on Start Test or F1.

A dialog box appears indicating the various test connections that are available (Figure 4.6).

5. Select the desired test configuration by clicking on the connection and then click START.

Figure 4.6 M5100 SFRA Instrument Run Dialog Box

The M5100 SFRA Instrument begins the test.

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Monitoring Test Status

Monitoring Test StatusThe M5100 SFRA software has two indicators on the user interface that show the status of the current test being run. The Trigger Status should indicate Measurement OK and Test Running should be flashing.

The Test Status field shows the percentage of the current test completed and upon completion of the test, Test Complete and 100% Complete are shown in the bottom right hand corner of the screen.

For more information regarding the status and progress indicators, refer to Chapter 3 ”M5100 SFRA Software”.

Response results begin appearing as soon as the test set begins receiving the data and the software continues to plot the results in real-time until the test is complete.

Aborting a Test• Click Abort Test or press the F2 function key to abort the test.

The Abort Test function only affects the active trace; previous data traces are not lost. Once a test is aborted, two options exist:

• Keep all data associated with the aborted trace.• Disregard and delete any data associated with the aborted trace.

Keeping data from an aborted test results in incomplete traces on the screen. The software saves these incomplete traces as if they are normal, so they can be recalled in the future. If the aborted test has no value then it should disregarded. If the data is disregarded, then only the data associated with the specific trace is deleted. All data on the screen prior to the abort test is unaffected.

Data ManagementData management consists of:

• Saving Data• Recalling Data• Remote• Printing• Shut Down

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Saving DataOnce a full scan of all the test connections is completed, data is saved to either the hard disk or USB storage device, such as a floppy drive or flash card.

To save data:

1. Select the File menu and choose Save Data.

The dialog box in Figure 4.7 appears.

Figure 4.7 Save Dialog Box

2. Select the appropriate directory in which to save from the Save in field.

The filename is already filled in from the Nameplate Data screen which was completed earlier. If the filename is not filled in or is incomplete, choose Cancel and return to the Nameplate Data tab to properly fill in the nameplate information. Once completed, return to the Save Data window.

3. Click Save. The data is now stored for future use.

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Recalling Data

Recalling DataStored data can be recalled by using the Recall Data function. Data can be recalled in parts or in whole, which allows the data from different sources to be viewed, overlaid, and combined. Data is stored in ASCII delimited format specific to the M5100 SFRA Instrument and is designated with a .csv extension. The M5100 SFRA Instrument is capable of recalling and saving up to 9 traces at once.

The Recall Data function is useful when comparing newly acquired data to historical data. Overlaying traces from different test dates allows an effective comparison to be made. The overlaying of data traces is not limited to data from the same unit.

Because data from multiple units can be overlaid, multiple nameplates can be viewed, recalled, and saved together. When recalling data, it is possible to load and view several nameplates, however only one can be viewed at a time.

To recall data:

1. Select Recall Data and the window shown in Figure 4.8 appears.

Figure 4.8 Open File Dialog Box

2. Browse to and select the files to open.

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Overlaying PlotsIf it is desired to view multiple traces or multiple traces from different files:

1. Use the Recall Data procedure to open a file.

2. Repeat as required for up to 9 plots.

Once all plots are chosen from all files, the data is displayed under the Magnitude tab. All plots are overlaid with the various color-coded connections shown. This allows for overlaying results between different phases of different transformers for comparison purposes.

To clear any of the plots during viewing, refer to ”Clear Graph” on page 3-7 of Chapter 3.

PrintingTo print the M5100 SFRA results:

• Choose the File menu and select the Print Screen option.

This prints only the active screen to the Windows default printer. The filename is printed at the top of the page. To print other screens within the same file, choose the appropriate tab to display the screen and then choose the Print Screen option again.

Powering DownThe M5100 SFRA Instrument uses Windows 2000 as its operating system. Windows 2000 requires that all programs be closed, and the software shut down before powering down the instrument. To exit the M5100 SFRA software and shutdown the instrument:

1. Select File from the menu bar and then select Quit.

The M5100 SFRA software closes.

2. Click Start and click Shut Down.

Windows 2000 ends all tasks and notifies the user to power down the instrument.

NOTE If the M5100 SFRA Instrument is incorrectly powered down, the operating system will go through a lengthy hard drive scan the next time the instrument is powered up.

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5. Data Interpretation

Frequency-dependant Transformer Equivalent CircuitThe power transformer equivalent circuit is a very complicated network of distributed resistive, capacitive and inductive elements. These include:

• Capacitance between the neighboring turns of the same winding.• Capacitance between the turns of different windings.• Capacitance between the turns and the ground.• Turns self-inductance.• Turns mutual inductance.• Conductor dc resistance.• Resistance that accounts for dielectric losses in insulation.• Resistance that accounts for eddy losses in conducting and

magnetic components.

Depending on the test leads connection, the equivalent circuit involved in the measurement represents an individual phase of the winding, the space between phases in a given winding or the space between the windings. Size of the conductors, diameters of the coils, distance between the coils, distance between the windings, number of turns, type of the core, winding configuration, type and thickness of insulation, geometry and size of supporting material are among the factors that define the elements of the equivalent circuit. Furthermore, each element is specific to the transformer design and even influenced by the ability of the manufacturing shop to replicate the units of the same design. Therefore, there is a direct relationship between the geometry of core-winding configuration and the network of distributed resistive, capacitive and inductive elements.

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Diagnostic Significance of Frequency Ranges

Since reactance of capacitive and inductive elements is frequency dependent, the contribution of each element to the overall network impedance varies with frequency making the equivalent circuit unique at each frequency. Therefore, the signature that represents the changing continuum of the network impedance with frequency uniquely describes the geometry of the core-winding configuration for a given unit and carries a wealth of diagnostic information. The network impedance, which is the ratio of the output and input signals, is often referred to as the transfer function. The frequency response analysis (SFRA) uses the transfer function behavior over the specified range of frequencies as the transformer diagnostic signature. Being a complex variable, the transfer function is described by the magnitude and the phase angle.

Diagnostic Significance of Frequency RangesDiagnostics of frequency ranges are discussed on two levels:

• Per-phase Measurement• Inter-winding Measurement

Per-phase MeasurementAs the name implies, the per-phase measurement targets the individual phase of a given winding. At low frequencies, the influence of capacitance is negligible and the winding behaves as an inductor. Therefore, the attenuation (described by the magnitude of the transfer function) and the phase shift (described by the phase of the transfer function) of the low-frequency sinusoidal signals, passing through the winding, are determined by inductive and resistive nature of the network. The inductive characteristics are determined by the magnetic circuit of the core and the resistive characteristics are dominated by the resistance of the output measuring cable. An example of transfer function magnitude and phase for a per-phase measurement is shown in Figure 5.1 and Figure 5.2. In Figure 5.2 the phase angle is around −80 degrees, indicating the inductive nature of the total impedance (in the region below 1 kHz). For a three-legged core-type unit, the magnetic flux coupled with the outer phase (H1-H3 or H3-H2 in Figure 5.1) faces a different reluctance than the flux coupled with the middle phase (H2-H1 in Figure 5.1). Therefore, the corresponding magnitude traces, in the low frequency range, differ as well, i.e., the traces for the two outer phases

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correlate very closely and are shifted from the middle-phase trace. The presence of the residual magnetism may have an effect on relationship between the traces. This is the same phenomenon that, during exciting current and loss measurement, creates a pattern of two high similar and one lower reading under normal conditions and a slightly distorted pattern in the presence of residual magnetism.

Figure 5.1 Per-Phase Measurement – Magnitude of the Transfer Function

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Per-phase Measurement

Figure 5.2 Per-Phase Measurement – Phase of the Transfer Function

As the frequency of the input signal increases, the capacitive effects begin to dominate and the phase angle quickly becomes close to +90 degrees (in the region above 1 kHz). Now, the attenuation and the phase shift of the high-frequency sinusoidal signals, passing through the winding, are determined by inductive and capacitive nature of the network. However, in high-frequency region, the inductive characteristics are determined by the leakage flux coupling and the capacitive characteristics are determined by the various capacitance elements associated with individual turns. The propagation characteristic of the winding becomes complex as a result of the many resonance frequencies found in the high-frequency range. However, since the winding responses become less dependant on the magnetic circuit of the core, the traces of the three phases converge and become quite similar.

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As the frequency increases even further (over 100 kHz in Figure 5.2), the sinusoidal signals travel mostly outside the winding and reflect the other elements found in the transformer, e.g., leads, support insulation, etc. The magnitude and the phase of the transfer function in that frequency region are influenced by the inductive/capacitive/resistive nature of these elements.

Although most of the low-frequency magnitude responses exhibit a typical shape, there is no typical form responses in the high-frequency region. These vary greatly with design of the unit. Therefore, the frequency ranges noted in description of Figure 5.1 on page 5-3 and Figure 5.2 on page 5-4, are different for different units.

Inter-winding MeasurementAs the name implies, the inter-winding measurement targets the space between two windings in a given phase (Figure 5.3 and Figure 5.4 on page 5-7). In this measurement, the influence of the magnetic circuit of the core is excluded by floating the remaining transformer terminals.

For frequency ranges up to 100 kHz, the attenuation and the phase shift of sinusoidal signals, passing through the winding, are determined by the capacitive nature of the network. The capacitive characteristics are determined by the various capacitance elements associated with individual turns. This produces traces for three phases that are quite similar.

As the frequency increases further (over 100 kHz in Figure 5.4 on page 5-7), the sinusoidal signals travel mostly outside the winding and reflect the other elements found in the transformer, e.g., leads, support insulation, etc. The magnitude and the phase of the transfer function in that frequency region are influenced by the inductive/capacitive/resistive nature of these elements.

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Inter-winding Measurement

Figure 5.3 Inter-Winding Measurement – Magnitude of the Transfer Function

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Figure 5.4 Inter-Winding Measurement – Phase of the Transfer Function

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Analysis of Test Data

Analysis of Test DataTopics concerned with analysis of test data include:

• Initial Measurement• Subsequent Measurement• Other Diagnostic Measurements

Initial MeasurementPresent state of the art is such that analysis of SFRA data is based only on a subjective comparison of traces. For the initial measurement, the traces are analyzed for changes between responses of the three phases of the same transformer and changes between responses of transformers of the same design. Obviously, for the single-phase unit, only the later comparison is applicable.

The appearance of new features or major resonance frequency shifts are a cause for concern. When tapped windings are involved, it is useful to perform measurements on at least two tap positions, to assess whether differences in the trace originate from the tapped or untapped sections of the winding.

When interpreting differences observed between phases, bear in mind that for many windings there may be minor design differences associated with the disposition of internal connections between windings, bushings and tap-changers. These differences could introduce small differences between phases in the frequency response. Therefore, for the initial measurement, if minor differences between phases are observed, it is not possible to make an unambiguous conclusion about the presence of winding deformation. Fortunately, responses obtained for units of the same design can often serve as a reference data for each other.

Subsequent MeasurementFor the subsequent measurement, the traces are analyzed for changes between the initial and subsequent response. Considerations described for the initial measurement apply here as well.

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Other Diagnostic MeasurementsEach FRA diagnostic measurement has failure modes it is most sensitive to as its purpose in life. Therefore, understanding the significance of each measurement and knowing its associated failure modes is essential for a successful diagnostic investigation. Table 5.1 relates the typical failure modes with various diagnostic measurements. This table also shows that no single method can cover the multitude of problems occurring in transformers.

Table 5.1 Power Transformer Failure Modes and Diagnostic Measurements

Failure Mechanism Failure Mode Diagnostic Measurement

WindingsElectromagnetic forces caused by overcurrent conditions change the geometry of the winding, and so changing the measured leakage reactance.

Winding distortion

FRA, leakage reactance

Windings

Insulation failure creates a circuit coupled with the main flux. The resulting circulating current creates a load component in the measured exciting current and loss.

Turn-to-turn winding failure:a) one or more turns are short-circuited completely.b) two or more parallel strands of different turns are short-circuited.

FRA, exciting current and loss, DGA

WindingsInsulation failure creates a circuit coupled with the leakage flux. The resulting circulating current contributes a load component to the measured leakage loss.

Strands within the same turn are short-circuited.

Leakage loss, DGA

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Other Diagnostic Measurements

LTC windingsInsulation failure or miswiring affects the current circulating through a preventive autotransformer in the bridging position, or through a series autotransformer or a series transformer in all LTC positions. The change in the circulating current influences the load component in the measured exciting current and loss.

Open circuit, shorted turns or high resistance connections in the LTC preventive autotransformer, series autotransformer or series transformer.

FRA, exciting current and loss

LTC contactsContact problems affect the current circulating through the preventive autotransformer in bridging positions. The change in the circulating current influences the load components of the exciting current and the loss measured in the bridging positions.

Misalignment, mechanical problems, coking and wear of LTC and DETC contacts.

Exciting current and loss, DGA

DETC contactsContact problems change the resistance of the current path.

Misalignment, mechanical problems, coking and wear of LTC and DETC contacts.

DC winding resistance, DGA

ConductorsMovement of conductors results in the breaking of strands and the deterioration of terminations changing the resistance of the current path.

Open circuit, broken strands, termination problems

Exciting current and loss, DC winding resistance, DGA

Table 5.1 Power Transformer Failure Modes and Diagnostic Measurements (Continued)

Failure Mechanism Failure Mode Diagnostic Measurement

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CoreMovement or over excitation of the magnetic system creates a circuit coupled with the main flux. The resulting circulating current contributes a load component to the measured exciting current and loss.

Overheating due to (abnormal) circulating currents in the core, clamping components and through multiple core grounds.

FRA, exciting current and loss

Moisture, aging, contaminants, poor maintenance, and manufacturing defects leads to insulation deterioration.

Dielectric breakdown of insulation.

Power factor and capacitance (including measurements on bushings), oil tests, DGA

Table 5.1 Power Transformer Failure Modes and Diagnostic Measurements (Continued)

Failure Mechanism Failure Mode Diagnostic Measurement

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Appendix A. Application Tips

Summary of Verifying Functional OperationThe Calibration Test verifies the proper calibration of the M5100 SFRA Instrument and is performed first as a part of a standard practice. It is required that the instrument be calibrated only after it had been powered up for fifteen minutes in a reasonable ambient temperature environment. The M5100 SFRA Instrument prompts the operator through the procedure, which includes assuring that the Test Specimen Cable is disconnected from the system during the procedure and ending in confirmation of a successful calibration or instructions for a non-successful results.

The Cable Continuity Test is performed next. It verifies the proper condition of the Test Specimen Cable, which is connected to the M5100 SFRA Instrument and then short circuited by connecting alligator clamps. Since there is no attenuation, signal loss between the Source/Reference and Measure, the resulting data graph plots along the 0dB horizontal line as frequency increases.

The Open Circuit Cable Test is performed next. It is performed for two reasons:

• To confirm that the M5100 SFRA Instrument recognizes an open circuit condition for any or all of the connections of the Test Specimen Cable.

• To train the operator to recognize this condition and correct it, which results in more efficient and accurate accumulation of good SFRA test data.

For all open circuit cables, Source/Reference and Measure in any combination, the NO TRIGGER - Check Ref Signal results and no plot of data occurs. When the Measure cable is the disconnected lead, an infinite attenuation is being measured and the result is a data plot that shows (-)85db to (-)115 dB with deviations that are caused by noise.

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Cables

CablesRG-58 50 Ohm impedance matched test leads are used. The SFRA measurement requires a matched impedance signal cable, and performs a single-ended measurement, i.e., the signal with respect to the instrument ground. Thus, the shield of the signal cable must be connected to the chassis via RF BCN connectors.

Practical field experience dictates the leads be 60 ft. in length. This length has been selected as being the minimum length required to test the largest transformers from a location on the ground adjacent to the unit. Nevertheless, it is the lead length that determines the maximum effective frequency. At lengths of 60 ft., the cable approximates the wavelengths of the higher measurement frequencies, and there is probably little to be gained from the 2-10 MHz scan. As long as the cable is less than ¼ of a wavelength in length, the short cable approximation can be used. At lengths greater than ¼ of a wavelength, phasing effects start to occur. It turns out that at 60 ft., the frequency cutoff with respect to wavelength is approximately 2 MHz. Figure A.1 on page A-3 illustrates the effects of the cables at higher frequencies; different attenuation levels are plotted to compare what influence the cables have on the noise to signal ratio. The attenuation was accomplished using a 50 Ohm impedance matching resistor divider network.

It is important for the operator to not only recognize any problems with the cables, but to be prepared to confirm a problem further by, for example, having an ohmmeter available when a cable is recognized by the M5100 SFRA Instrument as having an open circuit condition. The connections to the apparatus must be contaminant free, metal-to-metal junctions. This assures not only reliable and efficient SFRA data collection, but helps to reduce the effects of noise and interference inherent in a substation environment. Remember that a ba connection to the apparatus can appear as an open circuit cable.

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Figure A.1 High Frequency Effects on Cables

Since time is usually critical when testing a transformer, it is important to verify the proper operation of the M5100 SFRA Instrument, its cabling system and software, prior to connecting to the apparatus. This is comprised of the following:

• ”Instrument Setup” on page A-4• ”Calibration Test” on page A-4• ”Continuity Test” on page A-5• ”Open Circuit Test” on page A-6

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Instrument Setup

Instrument SetupTo cable the instrument:

1. Attach the 30’ Chassis Ground Cable clamp to the grounding plate on the transformer and insert the cam-lock connector into the instrument, twisting in a clockwise rotation to insure locking of the connection.

Gently attempt to pull this connection straight out to verify that locking has occurred. Refer to Figure 4.3 on page 4-6.

2. Check that the Power On/Off rocker switch is in the Off position and connect the power cord from the M5100 SFRA Instrument to an appropriate AC power source.

3. Turn on the power switch located on the back of the M5100 SFRA Instrument.

The M5100 SFRA software should automatically launch from the desktop. If not, to initiate the program, do one of the following:

• Double-click on the M5100 SFRA icon, or • Go to START|PROGRAMS|DOBLE M5100|M5100 v.1.1. to

open the software.

Wait for the main testing screen to appear.

Calibration TestThe Calibration Test assures that the M5100 SFRA Instrument provides accurate test data.

Before performing any SFRA testing, a calibration must be performed on the instrument after it has been on for approximately 15 minutes. The calibration routine needs to be performed only once for any particular testing session, not before each individual test.

To do this:

1. Select Calibrate from the Text Bar.

A dialog box appears reminding the operator that the instrument should be at room temperature for a minimum of fifteen minutes.

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2. Click OK to continue or CANCEL to allow warm up time before proceeding.

A dialog box appears stating Disconnect All Test Leads - Press OK When Ready To Start Automatic Scope Calibration.

3. Since no test leads are connected, select OK

A dialog box appears stating Performing Scope Card Calibration Sequence - Please Stand By. This procedure takes about two minutes to perform.

When the calibration procedure is completed, another dialog box appears stating Scope Calibration Complete.

4. Select OK to proceed.

If there is a failure in the calibration procedure, the operator is prompted and is directed to contact the Doble Engineering Service Department.

Continuity TestThe Cable Continuity Test verifies that the Specimen Cable is free of open circuit conductors and faulty connectors.

To connect the test Specimen Cable:

1. Connect the yellow, red, and black marked cables to the instrument.

2. Connect the RED and BLACK main clips together, shorting them.

These are the large clamps at the end of the cables.

3. Connect the RED and BLACK ground shield clips together, shorting them.

These are the smaller clips, which are attached directly on the cable. They are located approximately ¾ of the distance toward the end of the cables.

4. Press F1 or select START TEST to start the test.

A dialog box appears that asks the operator to select a plot for data storage, the default is unused1.

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Open Circuit Test

5. Select START

The Trigger Status indicates Measurement OK and Test Running begins flashing above the Test Status % Bar.

The default color of unused1 is WHITE, therefore a WHITE trace begins to form along the 0.00 dB horizontal line and continues until it begins to deviate negatively at the highest frequencies.

See Figure A.1 on page A-3, to compare the results. If there is a dissimilarity, (e.g. deviations of the trace into (-)dB regions prior to the highest frequencies) there may be a problem with the cables. To fix this:

a. Check the cables for any visual damage along their length, as well as the connector and alligator clips.

b. Redo the connections and repeat the test.

If the problem repeats, contact the Doble Engineering 617.926.4900 for further assistance.

Open Circuit TestThe Open Circuit Cable Test recognizes how the M5100 SFRA Instrument responds to open circuit conditions for the Source YELLOW and Reference RED cables with alert messages and the graphic display of an open circuit for the Measure BLACK cable. To perform this test:

1. Connect the RED and BLACK marked cables to the instrument, leaving the yellow cable disconnected.

2. Press F1 or select START TEST to start the test.

A dialog box appears that asks the operator to select a plot for storing the data, the default is unused1.

3. Click START.

The Trigger Status indicates Measurement OK and Test Running begins flashing above the Test Status % Bar for approximately 2-3 seconds, after which the Trigger Status changes to flashing RED and a message stating NO TRIGGER - Check Ref Signal appears. No graphing of data occurs.

Refer to Figure A.1 on page A-3 to view the NO TRIGGER - Check Ref Signal.

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4. Press F2 or select ABORT TEST to reset the M5100 SFRA Instrument.

The Test Status states Test Aborted and a dialog box appears asking Do you wish to keep the current data or clear it?.

5. Click Clear.

6. Reconnect the Source YELLOW cable.

7. Repeat the procedure for the Reference RED cable, with the same results.

8. Repeat the procedure for the Source YELLOW, Reference RED and the Measure BLACK cables with the same results.

Although it would be rare for all three cables to have open circuit conditions, it would be more common an occurrence that the cables were not to be connected. So knowledge of the M5100 SFRA Instrument’s response will assist the operator in recognizing the problem and correcting for it.

GroundingNOTE Proper grounding of the test instrument is essential.

As discussed in the introduction of two-port networks, zero impedance across the negative or lower terminal is desired. Proper grounding isolates the measured transfer function to the transformer and removes any unwanted ground impedance or cable effects.

The following verification is recommended: The bushing flange must be solidly grounded to the transformer tank. Often, a small impedance is present. Also, the ground clips must solidly bite into the respective bushing flanges. Any paint or contamination on this surface can affect the measurement.

NoiseNoise and interference can be introduced into a measurement through various means. Noise and interference influences a measurement by any of the following:

• Generated by the measurement instrument and coupled directly.• Stray electrostatic and electromagnetic fields.• Connection characteristics of the leads.

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Noise

For simplification purposes, noise and interference should be considered separately. Noise has two categories: white or broadband and 1/f or low frequency noise.

Because SFRA testing takes place in harsh electrical and mechanical environments, on average, the white noise floor appears at –80 dB. Measurements below –80 dB are often contaminated with a hash like appearance. However, averaging techniques have been proven useful in reducing the effects of white noise below –80 dB.

1/f noise is a phenomena which has a linear effect on lower frequencies. 1/f noise appears as a pole affecting frequencies below 300 Hz, which are heavily attenuated. Figure A.2 illustrates the effect of 1/f noise. The test specimen is a 400 kOhm load.

Figure A.2 High Frequency Effects on Noise

Due to the sensitive nature of the M5100 SFRA Instrument, interference cannot be avoided. Any interference with a broadband less than 10 MHz can affect the measurement. Interference, such as mechanical vibration, power line pick-up (50 Hz and 60 Hz), and RF (AM/FM broadcasts), are usually present during testing. They are most noticeable when the measured output signal is attenuated. Power line pick-up often has several harmonics included.

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Appendix B. M5100 SFRA Instrument Specifications

Table B.1 lists the controller specifications.

Table B.2 lists the analog source specifications.

Table B.1 Controller

Item Description

Processor Pentium III 866 MHz w/256 MB SDRAM

Operating System Microsoft Windows 2000

Communication 1 serial, 1 parallel, 2 USB, 10 BaseT Ethernet

Data Storage 15 GB Hard Drive, USB 3.5” Floppy Drive, Optional CDROM 24X Max

Keyboard 87 Key Ultra Low Profile

Mouse Two Button Touchpad PS/2

Display SVGA, 10.4” Color TFT, 640 X 480

Table B.2 Analog Source

Item Description

Channels 1

Frequency Range 10 Hz − 10 MHz

Voltage Output 10 V peak-to-peak at 50 Ohms

Output Coupling DC

Output Impedance 50 Ohms

Protection Short circuit protected

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Table B.3 lists the analog input specifications.

Table B.4 lists the M5100 SFRA software specifications.

Table B.5 lists the data collection specifications.

Table B.3 Analog Inputs

Item Description

Channels 2

Sampling Simultaneously

Frequency Range 10 Hz − 10 MHz

Bandwidth 10 MHz max

Max Sample Rate 100 MS/s

Input Impedance 50 Ohms

Input Protection ± 42 VDC continuous

Calibration Interval Internal (24 hr.), External (5 years)

Table B.4 M5100 SFRA Software

Item Description

Instrument M5100 SFRA Field

PC M5100 SFRA PC for Windows 98/2000/NT 4.0

Table B.5 Data Collection

Item Description

Test Method Sweep frequency

Frequency Range 10 Hz − 10 MHz

Number of Points 1250 logarithmically spaced

Accuracy ± 1 dB > −80 dB

IF Bandwidth 10% of active frequency

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Table B.6 lists the data display specifications.

Table B.7 lists the physical specifications.

Table B.6 Data Display

Item Description

Scaling Linear/Log

Frequency Range 10 Hz − 10 MHz, User defined within frequency range

Plotting Frequency vs. Magnitude/Phase

Table B.7 Physical

Item Description

Instrument Weight 28 lbs. / 12.7 kg

Dimensions 10.0 x 16.0 x 15.5 in. / 25.4 x 40.6 x 39.4 cm

Transport Shock High impact, molded, flame retardant, ABS – meets National Safe Transit Association testing specification No. 1A for immunity to severe shock and vibration.

AC Input Voltage 90 – 265 VAC universal

AC Input Frequency

50 or 60 Hz

AC Protection 5A circuit breaker

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Table B.8 lists the environmental specifications.

Table B.8 Environmental

Item Description

Operating Ambient Temperature

0 to 50° C (IEC-60068-2-1 and IEC-60068-2-2)

Operating Relative Humidity

10% to 90% non-condensing (IEC-60068-2-56)

Storage Ambient Temperature

−20° to 70° C (IEC-60068-2-1 and IEC-60068-2-2)

Storage Relative Humidity

5% to 90% non-condensing (IEC-60068-2-56)

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Index

AAbort test 3-10Accessories

cables 2-3grounds 2-3

Analysis mode 3-8Analysis of Test Data

initial measurement 5-8subsequent measurement 5-8

Anti-Aliased 3-17Autorange 3-12

BBar plots 3-18

CCables 2-3Cables, tips A-2Calibrate 3-8Calibration 4-4Clear graph 3-7Clipping 3-12Color 3-17Common plots 3-17Controller 2-2Current frequency 3-11Cursor movement tool 3-16Cursors 3-16

DData display 3-12Data Management

4-20DETC 3-13Diagnostic significance of frequency ranges, explained 5-2Display band 3-15Document Conventions 1-x

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Drive Amplitude 3-11

FFile 3-4Fill base line 3-18Frequency scale 3-8Frequency-dependant transformer equivalent circuit, explained 5-1

GGraph palette 3-15Grounding, tips A-7Grounds 2-3Guide, structure 1-ix

IInterpolation 3-18

LLine style 3-17Line width 3-17LTC 3-14

MM5100 SFRA Instrument

accessories 2-3controller 2-2hardware 2-1operating system 3-1software 3-1

M5100 SFRA Office View Software 3-18installation 3-18, 3-19PC requirements 3-18

M5100 SFRA Softwareabort test 3-10analysis mode 3-8autorange 3-12calibrate 3-8clear graph 3-7clipping 3-12current frequency 3-11cursor movement tool 3-16cursors 3-16

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data display 3-12display band 3-15drive amplitude 3-11File 3-4frequency scale 3-8graph palette 3-15magnitude 3-12menu choices 3-3nameplate 3-13pan 3-16phase 3-12plot legend 3-17print screen 3-5quit 3-5recall data 3-4response 3-11save data 3-5select bands 3-6start test 3-9sub band magnitude 3-12sub band phase 3-13test initiation and control 3-8test initiation, control 3-9test status 3-10test status indicator 3-11trigger status 3-10vertical range 3-11waveform 3-12zoom tool 3-16

Magnitude 3-12Menu choices 3-3

NNameplate 3-13Nameplate to edit/view 3-14Noise, tips A-7

OOperating system 3-1

PPan 3-16Phase 3-12

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Plot legend 3-17Point style 3-18Print screen 3-5

QQuit Program 3-5

RRecall data 3-4Response 3-11

SSafety

4-1general rules 4-1

grounding 4-2personnel 4-2

Save data 3-5Select bands 3-6SFRA Test Preparations

4-3apparatus connection 4-6diagrams 4-8test file creation 4-4

SFRA theory 1-2introduction 1-1

Software 3-1Start test 3-9Sub band magnitude 3-12Sub band phase 3-13

TTest

4-18aborting 4-20initializing 4-18monitoring 4-20overlaying plots 4-23power down 4-23printing 4-23recalling data 4-22saving data 4-21

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Test status 3-10Test Status Indicator 3-11Trigger Status 3-10

VVertical range 3-11

WWaveform 3-12

XX scale 3-18

YY scale 3-18

ZZoom tool 3-16

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