Research on the Key Technologies of Control and Protection for Static Frequency Converter (SFC) Valve Group of Pumped Storage Units

Pumped storage power station has the functions of peak loading, valley filling, frequency modulation and emergency backup, etc. When the pumped storage power station is running under the working condition of the motor, the static frequency converter (SFC) can realize the smooth start of the synchronous motor, reduce the starting current and weaken the disturbance to the power grid. At present, SFC is the main starting mode of pumped storage unit. SFC can produce frequency variable AC power to start the pumped storage unit, with soft starting function. This paper introduces in detail the control structure of the static frequency converter (SFC) valve group of pumped storage unit and the key technology of control and protection of thyristors. It has solved the technical problems such as wide bandwidth pressure energy extraction and instantaneous protection of thyristor in the valve control unit, and has been applied in many pumped storage units.