基于PI与准PR联合控制的光伏并网电流优化

摘要

针对光伏并网逆变器在采用传统比例积分(PI)控制器时不能实现无静差跟踪和并网电流逆变器直流分量注入问题,提出PI与准PR联合控制的光伏并网电流优化策略.在介绍了PI与准PR联合控制的原理的基础上,详细分析了准PR控制的原理和算法实现.准PR控制能够实现无静差跟踪,PI与准PR联合控制实现了直流的抑制.采用Matlab/Simulink进行仿真研究,结果表明能够对并网电流的无静差控制,消除了单一PI控制所产生的相位误差,抑制了直流分量,并且具有良好的并网波形质量.%Photovoltaic (PV) grid inverter can't achieve static-error-free track while using conventional proportional integral (PI) and DC component of the current injection problem of grid inverter, for which, PI and quasi-proportional resonant (PR) control strategy of PV grid current optimization is proposed. The fundamentals of PI and quasi-PR controllers are introduced, and the principle and algorithm of quasi-PR are analyzed. Quasi-PR control can achieve static-error-free tracking, and PI and quasi-PR control strategy can suppress the DC component. Results of simulative study with MATLAB/Simulink show that, the static-error-free control of grid-connected current is realized, the phase error introduced by single PI controller is eliminated, the DC component is suppressed, and the excellent grid-connected waveform is achieved.