Phase-locking strategy and equivalent method in output negative sequence current control strategy

The fault characteristics of power grids have changed profoundly as traditional energy sources are replaced by new energy sources. The new national standard proposes a control strategy that involves outputting negative sequence reactive current, which requires new energy power supplies to output negative sequence reactive current. For the inverter new energy station, this paper analyses instantaneous power calculation in detail, proposes an indirect phase-locked method, uses a negative sequence voltage orientation reference frame, obtains each command value of the inverter new energy station that is easy to understand and build, then solves the equivalent circuit of the inverter new energy station under the output negative sequence reactive current control strategy, and obtains the corresponding circuit parameters. Finally, the rationality of the instruction setting and the correctness of the equivalent method are verified by simulation.