A control system for HVDC transmission by voltage sourced converters

Abstract

A national technical project is under way in Japan to develop a high-power voltage sourced converter and its control system for the future DC interconnection between AC systems. Three developed prototype 53 MVA GTO-based converters were manufactured and went into operation. As for the control system, the voltage margin method for two terminal, and the 2-stage DC voltage control method for multi-terminal DC link were developed. Field testing is being carried out at Shin-Shinano Substation of Tokyo Electric Power Company. Satisfactory results verify the superiority of the DC link with voltage sourced converters.