Long-term test of the equipment for ±500 kV DC converter station

The paper describes the long-term test of prototypes of thyristor valves, DC GIS (gas insulated switchgear), converter transformers, smoothing reactors and a DC filter. These were developed for a HVDC system of ±500 kV, 2800 MW. To verify the long-term stable operation of the thyristor valves, 8 kV, 3500 A light triggered thyristors were assembled into a module of a commercial SVC (static VAr compensator) and tested for one year in operation. The other prototypes were subjected to an accelerated life test under ±625 kV DC at the test site. After one year, the equipment was brought back to the factory and tested to their performance limits to evaluate their remaining insulation capability. Successful tests confirmed that equipment based on the above prototypes can endure for a suitably long time in operation