Research on the Low Voltage Ride- Through Technology for Variable Speed Pump Storage Group based on Rotor-Side Virtual Inductance

In order to improve the virtual equivalent inductance regulation ability of doubly-fed variable speed pumped storage unit (DFVSPSU), a novel control strategy based on equivalent virtual inductance is proposed in this paper. The dynamic mathematical model of the DFIGM is derived to analyze its transient characteristics under normal conditions and fault conditions. Based on the analysis of the optimal port impedance characteristics satisfying the rotor voltage and current constraints, a low voltage ride-through control strategy with virtual equivalent inductance is proposed. By controlling the rotor side port impedance to an appropriate inductance, the rotor voltage and current constraints could be satisfied at the same time, thus improving the controllable virtual equivalent inductance ability of the DFVSPSU system. In addition, this method can eliminate the electromagnetic torque ripple in the transient process. The effectiveness of the proposed control method is verified by both theoretical analysis and simulation results.