HVDC Transmission

References

1. HVDC Power Transmission System: - K.R. Padiyar

2. Electrical Power System: - C.L.Wadhw                                                                            

Introduction

Day by day load on the power system increases so power transmission capacity has to increase. It is possible only by increasing generating
capacity or by increasing the voltage level of the transmission. Every time it is not possible to increase the generating capacity and it is not economical to change the voltage level. Also it is not desirable to transmit a bulk amount of AC power through long transmission lines. The solution for this problem is HVDC transmission.

The work on HVDC was started in 1930 in Sweden by ASEA. First commercial installation was started in 1954 between Sweden and Denmark through sea water link. Its rating was 100 kV, 20 MW, 90 km.

Basically HVDC is more preferable for one of the following reasons

1. Bulk power transmission over long distance.

2. For short distance it is used for underground cable or sea water link.

3. Tie line interconnection for two asynchronous systems.

Development of HVDC Technology

1. Mercury arc valves – 1954 to 1961

2. Solid semiconductor valves- 1971

3. Microcontroller based control – 1979

4. Thyristorised CCC – 1994

5. IGBT (VSC) based control – 1998

6. Light HVDC – latest technology

The major inventors in HVDC technology are ABB, Siemens, L&T, ALSTORM, AREVA, BHEL