The concept of VSC Based HVDC Transmission are explained in this presentation

1. HIGH VOLTAGE DIRECT CURRENT TRANSMISSION
“VSC BASED HVDC TRANSMISSION”
V.KALAIRAJAN M.E;
ASSISTANT PROFESSOR,
ELECTRICALAND ELECTRONICS ENGINEERING
KONGUNADU COLLEGE OF ENGINERING AND TECHNOLOGY,TRICHY
KONGUNADU COLLEGE OF ENGINERING AND TECHNOLOGY, TRICHY VSC BASED HVDC TRANSMISSION 1

2. “VSC BASED HVDC TRANSMISSION”
VIEWS :
POWER CONTROL:
 VSC BASED HVDC TRANSMISSION.
 MODE1.
 MODE 2.
 ADVANTAGES OF VSC BASED HVDC LINK OVER LCC.
BASED HVDC LINK.
 LCC BASED HVDC LINK.
 VSC BASED HVDC LINK.
 TWO LEVEL VSC.
 CONCLUSION.
 REFERENCES.
KONGUNADU COLLEGE OF ENGINERING AND TECHNOLOGY, TRICHY VSC BASED HVDC TRANSMISSION 2

3. “VSC BASED HVDC TRANSMISSION”
 The first VSC Based HVDC link designed by Hellsjon in Sweden
in1997.
 VSC Based HVDC link viewed as two STATCOMs and two
terminals are interconnected by DC link.
MODE 1:
 S1,S2 close , S open  DC capacitors are not connected  it act
as two parallel STATCOMs.
MODE 2:
 S1,S2 open, S closed DC capacitors are connected it act as
BTB VSC link.
KONGUNADU COLLEGE OF ENGINERING AND TECHNOLOGY, TRICHY VSC BASED HVDC TRANSMISSION 3

4. “VSC BASED HVDC TRANSMISSION”
KONGUNADU COLLEGE OF ENGINERING AND TECHNOLOGY, TRICHY VSC BASED HVDC TRANSMISSION 4

5. “VSC BASED HVDC TRANSMISSION”
ADVANTAGES OF VSC BASED HVDC LINK OVER LCC
BASED HVDC LINK:
 VSC based HVDC link provides independent control of Real
and Reactive Power outputs.
 Reactive power output is +Ve or –Ve.
 A converter station can absorb or supply reactive power from
the system.
 It is used to regulate the bus voltage.
 In two terminal VSC based HVDC link one terminal
power flow control and Second terminal  Dc voltage
regulation.
 VSC no need of voltage source, so can use for passive loads.
KONGUNADU COLLEGE OF ENGINERING AND TECHNOLOGY, TRICHY VSC BASED HVDC TRANSMISSION 5

6. “VSC BASED HVDC TRANSMISSION”
 No commutation problems ( IGBT Switch).
 Harmonics filtering is simple by PWM method. For IGBT switch
carrier frequency is 2KHz.
 Fast Communication between terminals is no need for control.
 Power reversal does not require the Voltage reversal
(V Constant).So it is best for MTDC Systems.
 Used in offshore power plant to supply and receive power.
KONGUNADU COLLEGE OF ENGINERING AND TECHNOLOGY, TRICHY VSC BASED HVDC TRANSMISSION 6

7. “VSC BASED HVDC TRANSMISSION”
LCC BASED HVDC LINK:
 It is a classical method.
 The reactive power is function of Real power supplied.
 Reactive power supplied at both REC and INV station.
 Need current source for satisfactory operation.
VSC BASED HVDC LINK:
 Major components in converter station:
 CT converter Transformer supply power to converter station.
 L  Series reactor (0.15pu)isolate supply and Converter station
and limit current harmonics input side.
 PWM high frequency components eliminated by High pass
AC Filter(ACF).
 Over voltage limiter (Chopper)used for fast discharge of
capacitors when output DC Volt > Max DC bus volt.
 DC link switches (SL1,SL2)isolation of converter when DC
line fault (Protection).
KONGUNADU COLLEGE OF ENGINERING AND TECHNOLOGY, TRICHY VSC BASED HVDC TRANSMISSION 7

8. “VSC BASED HVDC TRANSMISSION”
TWO LEVEL VSC:
KONGUNADU COLLEGE OF ENGINERING AND TECHNOLOGY, TRICHY VSC BASED HVDC TRANSMISSION 8

9. “VSC BASED HVDC TRANSMISSION”
CONCLUSION:
 In this above presentation we can learn about basic concept of
VSC based HVDC transmission, advantages of VSC based
HVDC link over LCC, based HVDC link, LCC based HVDC
link, VSC based HVDC link, two level VSC.
REFERENCES:
 Padiyar, K. R., “HVDC power transmission system”, New Age
International (P) Ltd., New Delhi, Second Edition, 2010.
 Edward Wilson Kimbark, “Direct Current Transmission”, Vol. I,
Wiley interscience, New York, London, Sydney, 1971.
 Kundur P., “Power System Stability and Control”, McGraw-Hill,
1993.
 Google and Wikipedia.
9KONGUNADU COLLEGE OF ENGINERING AND TECHNOLOGY, TRICHY VSC BASED HVDC TRANSMISSION