基于PR控制的光伏并网电流优化控制

Optimal control of photovoltaic grid-connected current based on PR control

针对单相H6拓扑光伏并网逆变器在采用传统比例积分(PI)控制器跟踪正弦电流指令时会产生稳态误差和抗干扰能力差等问题,提出了一种基于比例谐振(PR)控制的H6拓扑单相光伏并网逆变器的总体控制策略。在介绍PR控制器原理的基础上,详细分析了其控制参数对系统性能的影响,并给出了PR控制应用于H6光伏逆变系统的工程设计方法。搭建了单相H6拓扑光伏并网逆变系统的仿真及实验平台,对理论分析结果进行了验证。结果表明PR控制器应用在单相H6拓扑光伏并网逆变控制系统中能够实现对并网电流的无静差控制,消除了PI控制所产生的相位误差,并且具有良好的并网波形质量。

When the single-phase photovohaic grid-connected inverter with H6 topology applies conventional PI controller to track the sinusoidal reference current,the steady-state error will be generated and its anti- interference capability becomes poor,for which ,an overall control strategy based on PR（Proportional Resonant） control is proposed. The fundamentals of PR controller are introduced,the influence of its control parameters on system property is analyzed and the engineering design principles of its application in the photovoltaic grid-connected inverter with H6 topology are given. The simulation model and experimental prototype of single-phase photovohaic grid-connected inverter system are built to verify the theoretical analysis and results indicate that,the static-error-free control of grid-connected current is realized,the phase error introduced by PI controller is eliminated and the excellent grid-connected waveform is achieved.