可调度型单相光伏并网逆变器控制策略研究

摘要

为实现中小容量单相光伏发电系统灵活、可控运行,弥补现有控制方法在有功功率调度方面存在的灵活性差、误差较大的问题,提出了一种基于输出电流控制的新型双闭环控制策略.首先进行外环控制器的寻优,然后对采用不同调制方式的电流滞环控制与新型双环控制策略进行对比分析.利用Matlab/Simulink软件构建了基于各种方案的并网逆变系统模型并进行仿真分析.结果表明,所提出的控制策略在有功功率调度方面具备显著优势,输出电流总谐波畸变率小,功率可调度范围宽,具有广阔的工程应用前景.%Aiming at realizing the flexible and controllable operation of small and medium-sized capacity single-phase photovoltaic (PV) system and solving the problems of traditional control methods such as inflexibility and error defect, a novel double-loop control strategy based on output current control is proposed. The first step of the research is optimization of outer loop controller. Then, a contrast between hysteresis current control with different modulation modes and the method raised in the paper is made. Grid-connected inverter simulated module is built with Matlab/Simulink software. Simulation results show the proposed control strategy has significant advantages in active power dispatching, namely, the total harmonic distortion rate of output current is smaller, and the active power dispatching range is wider. As a result, this method has a broad engineering application prospect.