A New Three+Phase Unbalanced Optimal Control Strategy of Distribution Network Based on Function Reuse of Micro-Source Grid-Connected Converter

Considering the quality of the output voltage, the distributed power supply needs to have a certain power quality control ability when the unbalanced fault occurs. In response to this requirement, this paper proposes a parallel system. An inverter is placed at the common coupling point of the main circuit and the power grid as an external device for fault ride-through when a serious fault drop. During normal operation, the parallel inverter does not operate, and the main circuit inverter outputs active power. Under asymmetric fault conditions, the parallel inverter injects reactive power to the common coupling point to limit AC current and grid voltage support. Firstly, the power model of the inverter under asymmetric conditions is analyzed in the first part. Then, the power quality management and capacity optimization strategy of the parallel system are described. Finally, the waveform results show the correctness and superiority of the capacity optimization strategy.