Optimization of Var-Voltage Regulation Control Strategy for Grid-Connected Inverter of Photovoltaic Power

Abstract

With the continuous increase of installed capacity of large photovoltaic power stations, the light intensity and temperature changes of photovoltaic power generation units themselves will cause grid-connected voltage fluctuation or even beyond the limit, so large photovoltaic power stations must participate in voltage regulation control. To solve this problem, the voltage distribution characteristics of the photovoltaic power station are firstly analyzed quantitatively, and the analysis shows the voltages at the photovoltaic inverter buses are relevant with the impedance of the collecting lines, the voltage at the PCC point, the location of the photovoltaic unit, and the output power of the photovoltaic unit. Furthermore, our work proposes the reactive power distribution strategy and voltage control strategy of photovoltaic power station based on particle swarm algorithm, and the correctness and feasibility of the proposed control strategy are verified by simulation, so as to ensure the rationality of the voltage control target of each photovoltaic inverters while taking into account the voltage of each photovoltaic unit.