ema sales mv presentation

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Medium Voltage Presentation

MV VFD overview of the Toshiba and MV VFD overview of the Toshiba and other Topologiesother Topologies

Abdou Barrow, EMA Inc.Abdou Barrow, EMA Inc.

www.emainc.netwww.emainc.net

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MV Variable Frequency Drive (VFD)

� Majority of MV VFDs are used on Pumps and Fans for energy savings Majority of MV VFDs are used on Pumps and Fans for energy savings and process control. Only 5% of all MV Motors are running on VFDs. and process control. Only 5% of all MV Motors are running on VFDs.

� Just like LV VFDs, MV VFDs includes built-in overload protection (no Just like LV VFDs, MV VFDs includes built-in overload protection (no heater elements required). Easily adjustable to the motor rated heater elements required). Easily adjustable to the motor rated

current (Voltage Source). current (Voltage Source).

� Adjusts both the frequency Adjusts both the frequency & voltage to the motor& voltage to the motor

� Reduces the inrush current to Reduces the inrush current to 115% (pumps and fans) of the 115% (pumps and fans) of the motor rated currentmotor rated current

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Variable Torque Loads

� Flow is directly proportional to speed.

� Torque & Torque & Pressure is directly

proportional to the square of the speed.

� Horsepower is directly proportional to the cube of the speed.

(n1 )3

(n2 )3

HP1

HP2

=

(n1 )2

(n2 )2

P1

P2

=

� The basic affinity laws can be converted for use with centrifugal fans and pumps.

n1

n2

F1

F2

=

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Current Source• Older technology• Uses an Active front end• Use Choke to smoothen out the current ripples• Cannot withstand accidental opening of the output contact, hence there is inherent

danger when VFD is used as sync bypass• Has to be tune to a specific motor

Voltage Source• Newer technology • Uses Buss capacitors to smoothen out the ripple voltage• Will run smaller motor with minimal changes on the VFD settings• More efficient

MV Topologies: Current and Voltage Source

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• 24 Pulse Input Transformer

• Meets IEEE 519-1992 at PCC

• Input Voltage up to 15KV

• 2300, 3300, 4160 and 6600V Motor Ratings

• 300 to 10,000HP

• Built to Maximize Personnel Safety

Phase Shifting Transformer of T300MVi

Input Current Input Voltage

Standard Features on Toshiba

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24 Pulse Phase Shifting Transformer

Improves line current wave and the load power factor

Independent secondary windings makes the main circuits of the power cells relatively isolated and it is low voltage on the secondary side which mirrors low voltage VFD, mature and proven technology

The transformer is fitted with over temperature protection

The 24/36 pulses lowers the input harmonic current to below IEEE519 specs at PCC


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Protections for VFD and personnel

VFD comes with lightening arrestor on the primary of the phase shifting transformer, Input Switch that is interlocked with the input contactor and also current limiting fuses

Switch Fuse M13

MECH INTERLOCK

E

E

M1A

ACL

Lightning ArrestorPT

T1

CPT

SH

Input LimitingCurrent

PowerMain


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Fused Input Protects Rectifiers-Non-standard for others

460V Secondary For Cooling Fan Power

24 Pulse Integral Input Transformer Three

Power

Cells • Input Taps +/- 5%• Over temperature

protection U,

V,

W


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Power Cell Racks Out Clear of Enclosure for Inspection / Removal

• Racking Mechanism, Easy Module Inspection

• Tin Plated Copper Low Inductance Bus Structure

• 120V Connector & Fuses Located at Bottom of Frame

• No Electrolytic Capacitors

Toshiba Topology

Power Section of T300MVi

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• Innovative Power Cell Topology

• Three Cell or Pole Design

• Medium Voltage 3300V IGBT’s

• Long Life Oil Filled Bus Caps (20-30 years) (not electrolytic)

• Connections Front Reduced MTTR

Toshiba Topology

Power Section of T300MVi

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. 5 Level Additive PWM Output (@4160V)

• Neutral Point Clamp Use Existing or Standard motors

• 1000 Ft Motor Lead Lengths without dV/dT Devices

• 2kHz Carrier Frequency. Allows Heat Reduction

• IGBT’S rated at 3,300V

OUTPUT VOLTAGE

NO LOAD CURRENT

Toshiba Topology

Advantages of the 5 Level Topology

Step Three:3600 Volts

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Others Topology

• 3 Level PWM Output Less component countAllows motor damage due to dV/dt without proper

filtersAllows insulation damage due to non NPC

Toshiba Topology

• 5 Level PWM Output with NPC Allows us to run existing motors up to 1000ft with

no filters. No risks to damaging motor insulation due to voltage spikes or cable insulations

Voltage Source Topologies

Comparison between 3 and 5 level Topology

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3 Level Output Waveform

5 Level Output

Waveform

Comparison between 3 and 5 level Topology

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T300MVi MV NEMA 1 Drive

LightningArrestor-Protects

the rectifier section

from Surges

VisibleDisconnect

Vacuum Contactor Soft Charge Circuit-Non standard for other

Inp VacuumContactor

4160/120VPotential

Transformer

50KAICFuses..NonStandard for others

Switchgrounded

when open

Overall Lay Out of Toshiba Topology

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Air Flow

Air Flow

Air Flow

• Air Exit at Top

• Highly Reliable, Three Phase 460V Fan Motors

• Redundant Fan Option Available

• Aluminum Washable Filter Screened Air (NEMA 1G) Intake at Bottom-Can be replaced while VFD is running

Standard Features on Toshiba Topology

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Transfer between drive and utility supply

Synchronous transfer to utility up tp 4 motors (Bumpless)

Synchronous transfer from utility

Bypass switchgear and controls

Manual VFD bypass

Bypass Options of Toshiba Topology

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T300MVi MV NEMA 1 Closed Transition: Bump-Less Transfer and Capture

A single-drive can be used to accelerate multiple motors to synchronous line speed, minimizing drive investment.

Bypass Options of Toshiba Topology

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• Graphical Display for T300 and MTX

• Same Design as low Voltage Toshiba Drive

• Intuitive Plain English Commands

• Ethernet Data Port on Front of Drive

ESCMON/PRG

User Friendly Keypad for Monitoring and Programming

T300MVi MV NEMA 1

Standard Features on Toshiba Topology

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Summary of IEEE-519 Conformity

Toshiba Allen-Bradley Siemens ABB Robicon

Internal Transformer

Required at extra cost



Internal transformer

< 4% current distortion (24 or

36 Pulses)5 Level Topology

80-120% current distortion – extra

cost to reduce

< 4% current distortion for 24 pulse; ~ 13% for

12 pulse3 level topology

~ 13% for 12 pulse3 level topology

< 4% current distortion

3 level topology

Internal control power requires only one source

Two sources required




Input visible disconnect

Extra cost & size Extra cost & size Extra cost & size Extra cost & size

Lightning Arrestor Optional Optional Optional Optional

Small Footprint Larger Larger Larger Larger

MV IGBT GTO HV IGBT IEGT LV IGBT

Harmonics

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View on the MTX (NEMA 3R)View on the MTX (NEMA 3R)

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T300MVi MV NEMA 1

• Disconnect Switch?• Fuses?• Input vacuum contactor?• Secondary sources of power?• Drive capability to run on an existing power system. • Is a power study necessary?• Are standard cables acceptable to connect the drive?• Is an existing or standard motor insulation acceptable for use on the drive?

Helpful Questions to qualify the right vendor before a purchase of MV drives

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Will the drive cause additional bearing shaft currents? Are motor stator RTD’s acceptable for use with the drive? Is the drive tuned to match the motor? Can it run smaller or different motors? What happens if the output is opened accidently? What happens if the output is grounded? What happens if the output is shorted?

T300MVi MV NEMA 1 and N3R Drive

N.B. Getting all these questions answered in writing will quickly eliminate trouble after installation

Helpful Questions to qualify the right vendor before a purchase of MV drives

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Synchronous Motors on Toshiba MV drives !

• AC exciters provided by EMA/Toshiba Houston • Installed base of Synchronous Motors

Water and Wastewater Market

Synchronous Motors

T300MVi MV NEMA 1

ema sales mv presentation

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