Patent ID: 10574064

Abstract:
An off-grid energy storage system includes n energy storage inverters identified by P1, P2, . . . , Pn sequentially, direct current sides of the inverters are connected to storage batteries, and alternate current sides of the inverters are connected in parallel. The storage battery connected to the direct current side of Pj is identified by Bj, where j=2, 3, . . . , n. A control system for an output waveform of P1 has a voltage-current double loop control structure, and a control system for an output waveform of Pj has a current loop control structure. A current loop given value of Pj is obtained by adding a current correction value of Pj to a current loop given value of P1. The current correction value of Pj is used for causing Bj to have the same operating parameter as B1.