Grid interconnection Inverter and grid frequency fluctuation suppression method

摘要

PROBLEM TO BE SOLVED: To provide a grid interconnection inverter and a method for suppressing fluctuation of a grid frequency, which can suppress a fluctuation of a grid frequency due to a sudden change in load or an output fluctuation of a renewable energy power source in a short time. An inverter that is connected to a power system 10 to which a synchronous generator 30 is connected and that suppresses fluctuations in system frequency by operating in accordance with an output active power command generated by a VSG function, the control thereof. The circuit is represented by the sum of the output active power setting value of the inverter, the value obtained by multiplying the deviation between the system frequency and the reference frequency by the pseudo attenuation coefficient, and the value obtained by multiplying the differential value of the system frequency by the pseudo inertia coefficient. In the grid interconnection inverter that drives the inverter main circuit 100 in accordance with the output active power command, the control circuit of the inverter reaches the maximum frequency fluctuation amount point after the system frequency reaches the maximum frequency fluctuation amount point. A means for adjusting so as to be smaller than the previous pseudo inertial coefficient is provided. [Selection diagram] Fig. 1