Active Voltage Regulation Control for Multi-VSI in Large-scale Renewable Energy Integrated Power System

As power system see large-scale renewable energy sources (RESs) integration continuously, the high penetration level of RESs makes voltage support capacity of power system decreased dramatically which makes voltage regulation an even greater challenge, especially at the point of coupling (PCC) with RESs. The reasonable answer is RESs provide active support capacity to power system. Voltage control at PCC requires a large amount of reactive power during fluctuation. This paper proposes an active voltage regulation control for multi-VSI in large-scale renewable energy integrated power system to regulate PCC voltage actively. The main control objective is regulating voltage deviation at PCC to avoid the overloading or protection action of devices. The control strategy ensures paralleled inverters share reactive power and realize autonomous operation of multi-machine parallel system. In addition, it provides plug-and-play operation options for RESs, and any RESs’ switching action will not affect the other units. Simulation results prove the correctness and feasibility of the control strategy.