Field testing of 53 MVA three-terminal DC link between power systems using GTO converters

Electric power companies, Central Research Institute of Electric Power Industry, and manufacturers in Japan are jointly carrying out a research project to develop a future DC link between power systems using multiple terminals of voltage source converters. This type of DC link has the following advantages: (1) the converter can transfer active power continuously, even if a severe voltage dip or waveform distortion has occurred in the AC system; (2) the converter can control reactive power independently of active power; and (3) multiple converter terminals can be easily connected via the DC circuit. The power can be flexibly interchanged in the multi-terminal configuration. 53 MVA (37.5 MW and 37.5 MVar) GTO converters, converter transformers, and control equipment were installed at the Shin-Shinano Substation of Tokyo Electric Power Company for a prototype three-terminal DC link between actual power systems, and field testing is being conducted.