upfc overview

Download UPFC Overview

Post on 09-Mar-2015

77 views

Category:

Documents

1 download

Embed Size (px)

TRANSCRIPT

Flexible AC Transmission System OverviewMariesa Crow 6/27/2006

Flexible AC Transmission SystemAlternating current transmission systems incorporating power electronics-based and other static controllers to enhance controllability and increase power transfer capability

Constraints on Useable Transmission Capacity Dynamic: Transient and dynamic stability Subsynchronous oscillations Dynamic overvoltages and undervoltages Voltage collapse Frequency collapse

Steady-State: Uneven power flow Excess reactive power flows Voltage capability Thermal capability

FACTS Controllers Static VAR Compensator - SVC Thyristor Controlled Series Compensator - TCSC Thyristor Controlled Phase Angle Regulator - TCPAR Static Synchronous Compensator - StatCom Solid State Series Compensator - SSSC Unified Power Flow Controller - UPFC

US FACTS InstallationsAEP/ Unified Power Flow Controller /100 MVA/ EPRI San Diego G&E/ STATCOM/100 MVA Mitsubishi NYPA/ Convertible Static Compensator/ 200 MVA Vermont Electric/ STATCOM/ 130 MVA/ Mitsubishi

Northeast Utilities/ STATCOM/ 150 MVA/ Areva (Alstom)

Eagle Pass (Texas) Back-to-back HVDC 37 MVA/ ABB CSWS (Texas) STATCOM/ 150 MVA / W-Siemens

TVA STATCOM/ 100MVA EPRI Austin Energy STATCOM/ 100MVA ABB

Power Flow Control Power transfer between areas can be affected by adjusting the net series impedance. Transmission line capability can be increased by installing a series capacitor which reduces the net series impedance.

UPFC

UPFC

may control voltage, impedance, and angle impacts active and reactive power flow in line

Basic Operation

UPFC Capabilities Increase transmission line capacity Direct power flow along selected lines Powerful system oscillation damping Voltage support and regulation Control of active and reactive power flow at both sending- and receiving-end

Operation Reactive power is generated or absorbed by the shunt inverter to control bus voltage Reactive power is generated or absorbed by the series inverter to control the real and/or reactive power flow on the transmission line

Contd A portion of the real power flow on the transmission line is drawn from the bus by the shunt inverter to charge the DC capacitor. Real power is inserted into the line through the series inverter.

Power flow in a transmission lineVSjX

VR

VSVR PSR ! sin H X and VR ! VS jXIR

PSR

HS

jXI

To increase PSR, increase H

VA

- Vinj +VB

VBE

Vinj

VA

VS

j

V

- Vinj +

Vd

S

VSV d sin E H d! XVd

S

E H

Vinj

j IVS

How is Vinj created?a1 b1 c1

+

Va2 b2 c2

a1

b1

c1

+V

a1 on, b1 on, c1 off Vab=0, Vbc=V, Vca = -V

a2

b2

c2

a1

b1

c1

+V

a1 on, b1 off, c1 off Vab=V, Vbc=0, Vca = -V

a2

b2

c2

a1

b1

c1

a1 on, b1 off, c1 on Vab=V, Vbc=-V, Vca = 0

+V

a2

b2

c2

Sine-triangle PWM1 0.8a

1 0.5 0

0.6 0.4 0.2b

V

0 1 0.5 0 0

100

200

300

400

500

600

700

-0.2 -0.4

V

0

100

200

300

400

500

600

700

1 -0.6ab

-0.8 -1 0 100 200 300 400 500 600 700

V

0 -1 0 100 200 300 400 500 600 700

Recommended

View more >