Toshiba’s Adjustable-Speed Pumped Storage Power System Has Started Commercial Operation–Dec 08, 2015– Tokyo, Japan (Techreleased) –  Toshiba has supplied 2nd unit of adjustable-speed pumped-storage hydro power generation system to Kyogoku power plant, operated by Hokkaido Electric Power Company (HEPCO). The unit has started commercial operation at the beginning of last month.

Generator-motor floor top of Kyogoku power plant

Unit 2 identical to unit 1, which started commercial operation in October last year, when compared with the conventional pumped storage power system, has a adjustable-speed pumped-storage power generation system with a wide operating range, as it can operate aligned to the demand-supply balance of a power system by raising the power output from zero to maximum output. The adaptation of this advanced technology resulted in an effective utilization of hydro resources and stable supply of power.

Toshiba’s state-of-the-art IEGT (Injection Enhanced Gate Transistor) device*1 is installed in adjustable speed secondary excitation equipment*2 and by simplifying the peripheral circuit, significant achievements of downsizing and loss reduction are accomplished. In addition, it is connected by a network of gateway*3 between monitoring and control, and this enables not only to control each unit separately, but also enables emergency operation by combining multiple unit in case a system accident due to thunderstorm by detecting power frequency fluctuation The distinguishing feature has made this technology a significant contributor in operational stability of the power system.

In 1894, Toshiba Group delivered the first Japanese-made 60kW hydroelectric generator to the Keage Power Station, Japan’s first commercial hydroelectric power plant. Since then, Toshiba has supplied over 2,000 hydro power generators with over 56,000MW generating capacity around the world. Toshiba Group supports efforts to secure a stable global power supply with renewable energy solutions, including hydroelectric, geothermal, wind and solar power systems.

*1  Injection enhanced gate transistors having high-voltage and large capacity are developed for power devices with low gate-on        voltage characteristics and a high interruption capability.

*2  Alternating current exciter in which secondary excitation method is applied; Converter device is connected to the                            secondary side (rotor) of generator or Generation motor.

*3    Equipment used in communication procedure (protocol) which relays mutual communication between various equipment            or networks.


Power plant name :  Kyogoku Power plant

Owner :  Hokkaido Electric Power company

Location : Abuta-gun, Kyogoku-cho, Hokkaido

Equipment delivered : 200MW x 2