Operating experiences of STATCOMs and a three-terminal HVDC system using voltage sourced converters in Japan

In Japan, two STATCOMs have been put into commercial service, and two other STATCOMs were operated for research purposes. These STATCOMs exhibit good operating performances and high reliability, though several failures were experienced. STATCOM converters were occasionally affected by the bus voltage waveshape distortion resulting from closing of AC capacitor banks or by DC magnetization of the converter transformer core, however, appropriate countermeasures were taken. A research project of a three-terminal HVDC system using voltage sourced converters was also carried out in Japan. Field test results showed the multi-terminal HVDC link by voltage sourced converters has good operating performances; the power flow can be flexibly interchanged between terminals, even in the event of an outage of a terminal or disturbances occurred in AC networks.