Calculation about active power regulation capacity of 300MW variable-speed pump-storage unit considering rotor dynamics

AC excitation pump-storage units will play an important role in the field of peak-shaving and frequency regulation in China’s power system. In order to give full play to its fast response ability, it is necessary to consider the calculation method of unit fast power regulation under the constraints of speed, power and so on. Firstly, based on the equivalent circuit of the AC excitation motor, the expression of the active and reactive power of the rotor at turbine mode is derived considering the voltage and power of the stator side; Secondly, considering the effect of slip rate on the apparent power of rotor, the fitting expression between the power regulation and the maximum change of speed is proposed, thus the fast power regulation calculation method and process of AC excitation pump-storage unit at turbine mode are proposed; Finally, taking the parameters of an actual pumping and storage unit as an example, the fast power regulation of the computer group under different power is analyzed, and the validity of the calculation method is verified by the time domain simulation results.