Static synchronous compensator to stabilize grid voltage for wind and photovoltaic power plant

The installation of wind and/or photovoltaic energy systems has rapidly increased in Japan. Electric power from renewable energy is always fluctuating owing to its time-varying nature. This weak interconnection of renewable energy in an electrical network affects the power quality and reliability. A static synchronous compensator (STATCOM) is required to stabilize the voltage fluctuation in a renewable energy power plant. This paper describes the design and test results of a new STATCOM that is suitable for renewable energy. The developed STATCOM has the following features, : a small harmonic distortion, synchronous connection for an interconnection transformer, and continuous operation capability during a grid fault.