D Var Statcom Introduction

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D-VAR® STATCOM Introduction

John Wright-Smith


STATCOM Basics


What is a STATCOM?

STATCOM = STATic* COMpensator

A STATCOM is a Power Electronic device comprised of Power Inverters to inject Reactive Current into a power system for the purpose of controlling system Voltage or Power Factor

* “Static” is a word that, in the past, power system engineers used to use instead of “electronic”


DC CapacitorsConverter

TransformerConverters

IGBT/GCT

Power System

STATCOM’s Main Components

IGBT - Insulated Gate Bipolar TransistorGCT – Gate Commutated Thyristor


Lf

Cf

1A

1B

2A

2B

ACDC

+

-

(Four Quadrant)

• Devices 1A, 1B, 2A and 2B are IGBT’s acting as fast switches

• Capacitors hold DC charge

• Lf and Cf are AC smoothing filter components

Single Phase Inverter


• Switches 1B and 2A are ON

• Switches 1A and 2B are OFF

• Current flows from DC bus via IGBT switches

ON

ON

current out

return current

Lf

Cf

1A

1B

2A

2B

ACDC

+

-

Positive Current Flow


• Switches 1A and 2B are ON

• Switches 1B and 2A are OFF

• Current flows from DC bus via IGBT switches

ON

ON

current out

return currentLf

Cf

1A

1B

2A

2B

ACDC

+

-

Negative Current Flow


Cur

rent

Time

Sine Wave Formed Using PWM(Pulse Width Modulation)

Switching frequency is about 4kHz


Only Reactive Power Either Capacitive or Inductive

Flows Through Converter

Inject Current 90° Out of Phase With Voltage


Three-Phase Inverter Module

+

-

Lf

Cf

3-Phase AC CurrentDC

• A six IGBT bridge can create three-phase current

• The DC bus is common to all three phases

• Again, IGBTs control currents at 90º compared to voltage, hence, controlled VAR flow


AMSC’s D-VAR® STATCOM

• Proprietary technology exclusively available from AMSC

• Provides dynamic reactive capability – both leading and lagging

• D-VAR STATCOM has overload capability of 2.67 times its continuous rating

• D-VAR STATCOM can seamlessly switch other devices and communicate with wind turbines to increase net reactive output


Reactive Power

2.67 Per Unit Rating

0

1 Per Unit Rating

Rated MVA Current

Continuous Reactive Current

1.0 2.0 80

Dynamic Reactive Current“Overload”

3.0

Proprietary Technology Provides a Combination of ContinuousDynamic VARs with Additional Overload Boost

D-VAR® STATCOM Dynamic Capability


Boosting Output Bucking Output

1.00

1.01

1.02

1.03

1.04

0.96

0.97

0.98

0.99

Reference Voltage = 1.00pu

Voltage (pu)

1x2x3x 1x 2x 3x

Deadband

Buck Droop = 2%

Boost Droop = 2%

Buck Hard Limit = 1.050pu

Boost Hard Limit = 0.950pu

1.05

0.95

D-VAR System’sDroop Setting Options

• Independent boost and buck droop slopes

• Droop slope adjustable from 1% to 10%

• Adjustable reference or target voltage

• Optional dead band and D-VAR output limits

• Can switch between voltage and power factor control

Fast Buck Turn On

Fast Boost Turn On

Buck Turn On

Boost Turn On

Dynamic Control and Regulation Control

D-VAR® System - Voltage Control


D-VAR ® System

Other Control Options Available

In addition to Voltage Control

• Power Factor Control

• Constant MVAR Control

• Power Oscillation Dampening

• Capacitor/Reactor Bank Switching Control

• Wind Farm/Solar Plant MVAR Output Control


Proprietary AMSC D-VAR provides truly seamless integration of shunt capacitor and/or reactor banks with STATCOM technology

Proprietary AMSC D-VAR® system provides truly seamless integration of shunt capacitor and/or reactor banks with STATCOM technology

AMSC™ Patented Soft Switch Technology

Result: Lower Cost Solution with Proven Performance


Other Shunt Type FACTS Devices

SVC = Static VAR CompensatorTSC: Thyristor Switched Capacitor

TSR: Thyristor Switched Reactor

TCR: Thyristor Controller Reactor

TSC & TSR are basically capacitors and reactors with power electronic switches (instead of mechanical switches)

TCR is effectively an infinitely variable reactor, but has the drawback of creating high harmonics


STATCOM is a Current Controlling Device

Q = I*VReactive Power is linearly dependent on Voltage

SVC is a Impedance Controlling Device

Q = V2/XReactive Power is dependent on the square of the Voltage

STATCOM vs. SVC Performance


100 MVAR D-VAR® STATCOM vs. 100 MVAR SVC Output

MVAR Output

Vp

u

MVAR


100 MVAR D-VAR® STATCOM With Overload vs. 100 MVAR SVC Output

MVAR Output

Vp

u

MVAR


SVCD-VAR STATCOM

• Modular

- Easy to expand and relocate

• Relatively small footprint

• Negligible harmonic injection

- Does not require external filter

• No potential to cause harmonic resonances

• Robust during low voltage conditions

• Has overload capability

• Air-cooled

D-VAR® STATCOMS vs. SVC

• Non-modular

- Difficult to expand and nearly impossible to relocate

• Larger footprint

• Substantial harmonics (TCRs)

- Typically requires external filter

• Potential for harmonic resonances

• Output limited by low voltage conditions

• No overload capability

• Typically liquid-cooled


D-VAR® STATCOM Overview


• Injects 3 MW instantaneous power from 3MJ of stored energy

• Total inverter choices of 3, 4, 6, or 8 MVA

• Up to 24 MVAR instantaneously for >1 second duration- up to +/- 8 MVAR continuous- continuous VAR output is either leading or lagging

• Additional switched capacitors can be added to increase controlled VAR supply

- transmission or distribution caps

• Reaction time <1 cycle

The D-SMES Trailer - Stored Energy


The D-SMES Trailer - Mobile


• Physical packaging changed from truck trailer to modular package (8’x8’x8’ for +/-4 MVAR)

• Improved ability for system controls, Modbus interface, Remote monitoring, etc.

• Proven performance of robust air cooling system in harsh/hostile environments (desert, arctic and everything in between)

Original 8 MVA Trailer Configuration

Continuous Capability 8 MVARDynamic Capability 24 MVAR

Current D-VAR Configuration

Continuous Capability 24 MVARDynamic Capability 64 MVAR

The D-VAR® PME - Pad Mounted System


Easy to Maintain – 24 x 7 Monitoring by AMSC Available

Checks: Filters clean/replace, general condition, louvers, fans, exhaust passages, check heater operation

Front louversExhaust louversFilters

The D-VAR® PME - Preventive Maintenance


The D-VAR® PME - Snow Hoods


D-VAR® Inverters - PME vs. Trailer

Three Phase InverterTwo 3-Phase Inverters = 500 kVAR

200 LBS

Single Phase InverterThree 1-Phase Inverters = 500 kVAR

60 LBS40% smaller

PME Trailer


• Helping utilities recovery from system voltage collapse events and increase power transfers

• Helping wind and solar farms meet a world wide variety of grid codes

• Helping industries improve their power quality by significantly reducing theirelectric outage costs

D-VAR® Applications


Utility Applications

Customer/ Application

– Northeast Utilities

– ITC

– Iceland

– Rayburn (G&T Co-op)

– Basin Electric

– National Grid (LIPA)

D-VAR System Output Range

-55 to +138 MVAR

-36.8 to +76.8 MVAR

-68 to 84.4 MVAR

-36.8 to +86.8 MVAR

-91 to 91 MVAR

-96 to 240 MVAR

Wind Farm Applications


– Caprock Wind Farm

– Centennial Wind Farm

– Lake Bonney Wind Farm

– Enbridge Wind Farm

-48 to +98 MVAR

-64 to +118 MVAR

-120 to +210 MVAR

Industrial Applications


– NW Semiconductor

– Canadian Mine

– Asian Semiconductor

– NW Semiconductor (2)


-168 to +168 MVAR

-80 to +80 MVAR

-107 to +107 MVAR

-72 to 72 MVAR

Versatile STATCOM Solution Deployed Worldwide

Examples of Large D-VAR® System Installations


-48 to +84 MVAR


Utilities – D-VAR System for Voltage Collapse and Regulation

Industrials – D-VAR System for Power Quality

Wind Farms – D-VAR System for LVRT, Regulations, Dynamic VARs

AMSC D-VAR® STATCOM System Installations


Utilities – D-VAR System for Voltage Collapse and Regulation

Industrials – D-VAR System for Power Quality

Wind Farms – D-VAR System for LVRT, Regulations, Dynamic VARs

AMSC Windtec® Designed Wind Turbine Generators

D-VAR RT System to Meet Grid Code Requirements

AMSC D-VAR® STATCOM and D-VAR STATCOM Off-Shoot Installations

Documents

D Var Statcom Introduction