Active and reactive power controls for the Gezhouba-Shanghai HVDC transmission scheme

The ±500 kV, 1200 MW HVDC transmission scheme, the first in China, interconnects the Central and Eastern China regional power systems over a distance of 1045 km. The scheme, known as GESHA, was commissioned in two stages in 1989 and 1990 respectively. The authors present a brief description of the HVDC transmission scheme and its principal modes of operation and the operating environment of the interconnected AC systems. Then, they focus on the novel control strategies for active and reactive powers adopted by the HVDC scheme to match the different requirements of the AC systems. Reactive power and AC voltage controls using the HVDC converter terminal-the first application in HVDC transmission systems-is explained in detail. Results of field tests made during the commissioning phases of the scheme to demonstrate these control features are also presented