Coordinated Voltage Control and Continuous Operation of the 80MVA STATCOM under Commercial Operation

We have newly developed an 80 MVA GCT STATCOM for the Kanzaki substation of the Kansai Electric Power Co., Inc. It started commercial operation in June, 2004. The main purpose of the STATCOM is to maintain voltage during single circuit connection of source to the substation resulting from an AC system fault in order not to break down load system of the substation. The developed STATCOM has three distinctive features: (1) a high-efficient, compact and AC filter-less system using multistage three-level GCT converter and customized PWM; (2) a coordinated voltage regulator with tap control of main transformers; and (3) a continuous operation from a single phase-ground fault through reclosing of the faulted circuit by limiter adjustments of the reactive current reference. This paper describes characteristics of the coordinated voltage and validity the continuous operation during AC system faults using data of commercial operations and the simulation results.