TEPCO´s experiences of automatic voltage controllers and SIPS as measures to prevent massive power outages

Recent movement pursuing economic efficiency & global environmental protection such as more installation of wind generations in electric power industries has caused increase in power exchange between regions and has made power system operation more challenging due to less operational margins. Generally, rapid cascading tripping of parallel transmission lines or transformers in the early stages of the major blackouts could not be stopped or limited by operator´s manual based operation. TEPCO (The Tokyo Electric Power Company, Inc.) has applied automatic controllers or system integrity protection schemes (SIPS) to avoid power system instability and to limit the impacts caused by system disturbances for many years. Those controllers and SIPS utilize microprocessor-based technology to realize sophisticated control and protection functions since 80s and have facilitated operators focusing on the system restoration during major incidents. This panel presentation will highlight TEPCO´s experiences and challenges on the design and operation of automatic controller sand SIPS.