instrumentation design considerations for digital energy

Jonathan P. Murray Bloomy Energy Systems

Business Unit Manager

Instrumentation Design Considerations for

Digital Energy System Monitoring and Control

Who We Are

▫ Vertical business unit of Bloomy Controls Inc.▫ Founded in 1992

▫ Windsor, CT; Marlborough, MA; Fair Lawn, NJ

▫ NI Platinum Alliance Partner since program began

▫ NI Certifications

▫ 16 Certified LabVIEW Architects

▫ 4 Certified TestStand Developers & Architects

▫ 17 Certified Professional Instructors

▫ Dedicated System Engineers for Energy Applications

What We Do

Provide test, data acquisition, and control products to

battery, automotive, and grid storage companies

Why We Do it

Major power disturbances in North America

We need updated Energy Systems…

How we can help:

Energy Storage Systems

Smart Grid technologies

Renewable Energy

Goal

Choose the right reconfigurable I/O (RIO) platform to

digitally monitor and control energy systems.

sbRIO

cRIO

PXI WSN

Design Considerations

▫ Channel count

▫ Channel distribution

▫ Sampling rates

▫ Resolution

▫ Accuracy & Precision

▫ Synchronization

▫ Isolation

The following design considerations need to be addressed

when determining the correct platform

Agenda

▫ Review Design Considerations

▫ Applications and Considerations

▫ Portable Renewable Energy Storage System

▫ Energy Storage System Performance Testing

▫ Micro Grid Monitoring System

▫ Wind Turbine Control and Monitoring

▫ Lessons Learned

▫ Questions

Channel Count and Distribution

Few channels

Many channels

Distribution

Sampling Rate

Samples acquired per unit time (usually seconds)

sampling too slowly:

- aliasing

- missed data

- introduction of nonexistent components

Nyquist Theorem

(2x highest frequency)

8x or better to acquire wave shape

Resolution

Number of discrete digital levels used to represent a

continuous analog signal

Example:

0 to 300V analog signal

8-bit ADC = 1.17V / digital level

24-bit ADC = 0.005V / digital level

Higher resolution:

- detect smaller amplitude changes

- reduce quantization error

Voltage

Time

Resolution

Reported digital level

Actual analog level

Quantization

error

Accuracy & Precision

Accuracy: How close the measurement is to the actual (true) value

Precision: How repeatable is the measurement

High Precision

Low Accuracy

High Accuracy

Low Precision

High Accuracy

High Precision

Use calibration techniques to achieve higher accuracy

Synchronization

Timing required to coordinate events to operate a system in

unison

Distribution Synchronization Methods:

- GPS

- IEEE 1588 (precision time protocol)

- IRIG-B

System and Channel Synchronization:

- Common clock

- Ensure data acquisition channels have

dedicated ADCs (simultaneous sampling)

Critical for power analytics

Isolation

Passing a signal from source to measurement device without a

physical connection

Common Methods:

- Analog Optocouplers (PCB level)

- Digital Isolation (PCB level)

- Isolation transformers (system level)

- Voltage / Current transducers (system level)

- Fiber optics (system level)

Case Study: Energy Storage System

Onboard Monitoring

▫ Portable Renewable Energy Storage System ▫ 4kW energy storage

▫ AC/DC bidirectional converter

▫ Inputs

▫ AC input

▫ DC input

▫ Renewable: Solar Panels

▫ Outputs

▫ 120 and 240 AC

▫ 28V DC

▫ NATO compatible

CACI proprietary

trailer design

http://www.google.com/imgres?imgurl=http://findmeaviking.com/Pages/shoulda been a viking/images/US Army Logo.gif&imgrefurl=http://findmeaviking.com/Pages/shoulda been a viking/Shoulda been a Viking.html&h=469&w=350&sz=10&tbnid=jT6ofvhscjmuFM:&tbnh=260&tbnw=194&prev=/images?q=us+army+logo&zoom=1&q=us+army+logo&hl=en&usg=__11ax3rOvFh8-yvYpZtKwoS8APKg=&sa=X&ei=4Au-TN-3AcOqlAep043jBw&ved=0CBYQ9QEwAA


Onboard Monitoring

▫ Deploy an embedded monitoring system to display vital

ESS information to soldiers.

▫ Incoming, available, and outgoing power

▫ Create an engineering view to monitor all critical steps in

power conversion and storage

▫ AC and DC voltages and currents

▫ BMS, master controller communications

▫ Temperature

▫ Light


Onboard Monitoring

▫ Design Considerations:

▫ Driving factor:

▫ Channel distribution: embedded (size constraints)

▫ Other considerations:

▫ Channel count: 20 voltage, 30 currents, 12 TC, RS232, CAN

▫ Sampling rates: 2Hz to 1 sample/15minutes configurable

▫ Resolution: course, 16bit was sufficient

▫ Accuracy: 1%

▫ Synchronization: not required, RMS power only

▫ Isolation and conditioning: PT, CT transducers


Onboard Monitoring

▫ RMS power measurements: ▫ Apparent power (VA) only

▫ RMS transducers

▫ Simultaneous measurements not required

Synchronized acquisition loops for each NI cRIO

9205 produces negligible phase shift between

voltage and current channels

▫ Phasor power measurements: ▫ Wave shape acquisition

▫ instantaneous transducers

▫ Simultaneous measurements required


Onboard Monitoring

Platform of choice: CRIO


Onboard Monitoring

Soldier View


Onboard Monitoring

Engineering View


Performance Testing

▫ Test 25kW to 2MW energy storage systems

▫ Evaluate performance for application-specific operations

▫ 200+ mixed signal acquisition channels

▫ Generate industry reports

▫ AC Input ▫ AC Voltage and current

▫ AC Power ▫ Real power

▫ Reactive power

▫ Power factor

▫ Battery Storage ▫ DC voltage and current

▫ DC power

▫ Sample cell voltage and current

▫ Inverter ▫ AC voltage and currents

▫ DC voltage and currents

▫ Frequency

▫ System ▫ demand power kW

▫ Energy kWh

▫ Efficiency (DC/AC)

▫ Temperatures & Airflow ▫ Ambient (Inside and Outside)

▫ Battery

▫ Inverter


Performance Testing

Measurements Tests

▫ Interconnect tests

▫ Startup / Shutdown / E-Stop

▫ Equipment failure

▫ Abnormal Grid Events

▫ Performance testing

▫ Power Rating

▫ Energy Rating

▫ Round trip efficiency

▫ Short / Long term test

▫ Application testing

▫ Frequency Regulation

▫ Peak Shaving

▫ Wind Farm Smoothing

Power quality measurements: NEN-EN-IEC 61000-4-30

Monitoring electric power quality: IEEE Std 1159-2009

Distributed power resources: IEEE Std 1547.1-2005


Performance Testing


▫ Driving factor:

▫ Channel count: over 200 channels

▫ Accuracy: 0.5%

▫ Sampling rates: 20kHz (total harmonic distortion)

▫ Synchronization: required for power quality analysis

▫ Isolation: 1200V, 2000A measurements


▫ Channel distribution: local to the trailer

▫ Resolution: hardware determined

▫ Total Harmonic Distortion (THD) ▫ Ratio of the sum of the power of harmonic components

to the fundamental frequency ▫ Fundamental frequency (f)

▫ Harmonics would be 2f, 3f, 4f…

▫ Usually cased by non-linearity of custom loads

▫ Harmonics can have the following effects: ▫ Distorted voltage and current waveforms

▫ Overheating of transformers & rotating equipment

▫ Neutral overloading (Triplen harmonics)

▫ Breakers and fuses tripping

▫ Wasted energy/high electric bills - kW & kWh

▫ Increased maintenance of equipment and machinery


Performance Testing

Why sampling rate

is important:

31st harmonic @ 60Hz

31f = 1860 Hz

Required sampling rates:

(minimal) 2x = 3720Hz

(better result) 8x = 14880Hz


Performance Testing

Platform of choice: PXI

Case Study: Micro Grid Monitoring

▫ Smart and Green Energy for Base Camps (SAGE)

▫ Reduce the quantity of fuel needed for electrical power

generation

▫ Focused components

▫ Alternative Energy Sources

▫ Smart Micro-Grid Technologies

▫ Storage and Power Generation

▫ Energy Efficient Shelters

All information is public knowledge provided on USALIA initiatives

Images courtesy of USALIA

▫ Develop and deliver a monitoring system to capture all

major base camp signals:

▫ Weather

▫ Temperature

▫ Gas flow

▫ Water flow

▫ Power

▫ Continuous monitoring for days to months

▫ Base camp components span 1000ft2

▫ Aggregate data for future analysis (DIAdem)




▫ Driving factor:

▫ Channel distribution: 1000ft2


▫ Channel count: 60

▫ Sampling rates: minimum 1 samples / 5 sec.

▫ Resolution: hardware driven

▫ Accuracy: hardware driven

▫ Synchronization: windows clock

▫ Isolation and conditioning: transducers


▫ Platform of choice: WSN

▫ Pro’s:

▫ Wireless connectivity

▫ Onboard programming

▫ Wireless updates

▫ Battery operated

▫ Con’s:

▫ External sensors still need power

▫ Limited channel types

▫ No direct write to data base

Weather stations

Flow

Temp

Power Meters

Case Study: Wind Turbine Control and

Monitoring

▫ 6kW and 100kW turbine R&D

▫ Monitors and record turbine and

environmental signals

▫ Control turbine position to

optimize energy and power

generation


Monitoring

cRIO

Tower base

Turbine

Turbine

Control

cRIO

Nacelle Transformer Hut

Hub

Metrology Tower

cRIO

Metrology

cRIO

Transformer

• Rotor speed/position

• Turbine Yaw position

• Stator flaps control

• Braking system control

• Wind speed/direction

• Turbine strain

• Power

• Wind speed and direction

• Temperature

• Pressure

• Humidity

• Tower strain

• Power

• System interface

▫ Design Considerations: ▫ Driving factors:

▫ Channel distribution:

▫ Cover a large area

▫ Embedded in turbine

▫ Sampling rate: 10kHz+ control loops

▫ Synchronization: simultaneous inputs for control loops and power measurements

▫ Interface: must run headless, remote update and monitoring


▫ Channel count: 100+

▫ Resolution: hardware determined

▫ Accuracy: hardware determined

▫ Isolation and conditioning: PT, CT, anemometers, external sensors


Monitoring

Platform of choice: cRIO


Monitoring

Case Study: Soldier-Borne Power

Monitoring

Develop a power monitoring system to acquire, record and display the average and peak power draw of soldier borne electronics and electrical devices.

▫ Wearable and portable

▫ Low power, light weight

▫ No tethering wires to devices

▫ Integrated sensors measuring current and voltage

▫ Wirelessly route data from soldier

▫ Continuous and transient data (100kS/s/ch)

▫ Open and modular architecture


Monitoring

▫ Design Considerations: ▫ Driving factors:

▫ Channel distribution: (onboard soldier)

▫ Light weight, low power

▫ Channel count: 40 (32 wired, 8 wireless)

▫ Sampling rate: 100kS/s/ch

▫ Resolution: 16bit

▫ Emissions and Interference testing


▫ Accuracy: hardware determined

▫ Isolation and conditioning: custom voltage, and current sensors

▫ Synchronization: RT time stamp

System could not be

larger than an MRE


Monitoring

Block Diagram


Monitoring

• 32 16-bit analog input channels

• 100 kS/s/channel Sampling Rate

• Xilinx FPGA

• 3.2 MHz Clocking Rate

• 8 High-Speed DIO Lines

• sbRIO 50-pin header plug

Platform of choice: sbRIO Custom Hardware

Wireless Sensors


Monitoring

Lessons Learned

▫ Perform end-to-end calibration to assist with overall accuracy

▫ Choose the right power transducer – RMS vs Instantaneous

▫ Isolation – essential contributor in high power systems

▫ Don’t assume the operator is going to use the system as intended (especially with High Voltage)

▫ Plan with the end goal in mind: ▫ R&D: select a platform where you can expand channel type and count

▫ Product: select a platform which can easily go to an embedded solution if high quantities are going to be produced

Jonathan Murray [email protected]

Thank you

Bloomy.com

instrumentation design considerations for digital energy

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