基于改进准PR控制的光伏并网电流控制器研究

Research on Photovoltaic Grid-connected Current Controller Based on Improved Quasi-PR Control

在光伏并网发电系统中,并网逆变器担负着举足轻重的作用,逆变器控制方法性能的优劣直接关系到并网电流质量的高低。针对传统准PR算法构造的控制器存在并网电流因参考电流信号发生阶跃而阶跃的情况和参考电流信号中低频噪声引起并网电流失真的问题,对准PR控制进行改进,采用了一种二自由度的准PR控制器构造方法,改进后的控制器可有效抑制输入信号中的阶跃和低频噪声对并网电流造成的影响。对改进后的控制器在MATLAB上进行了仿真,结果表明该方法可以有效改善准PR控制器存在的问题,提高并网电流的质量。

The grid-connected inverter plays an important role in photovoltaic grid-connected power generation system,the performance of inverter control strategy directly affects the quality of grid-connected current.For the quasi-PR control,the output signal step of controller exists owing to the input signal step,and the grid current will be distorted by the low-frequency noise in the input signal.In order to solve these problems,the performance of quasi-PR control should be improved,so a method of constructing quasi-PR controller with two degrees of freedom is adopted,the improved controller can effectively suppress the influence of the step and low-frequency noise in the input signal on the gridconnected current.The improved controller is simulated on MATLAB,and the results show that this method can effectively improve the existing problems of quasi-PR controller and improve the quality of grid-connected current.