基于改进滑模频率偏移法的光伏孤岛检测研究

Islanding Detection for PV Grid-connected System Based on Improved Slip-mode Frequency Shift

孤岛检测是光伏并网系统的必备功能之一,检测性能的优劣直接关系到设备的安全运行,在总结现有孤岛检测方法的基础上,针对传统滑模频率偏移法有检测失败的可能,提出一种改进型算法。首先阐述了改进型滑模频率偏移算法的工作原理,其次进行了改进型滑模频率偏移算法的参数优化和盲区分析,最后在考虑不同负载情形下,利用Matlab/Simulink搭建了5kW光伏并网孤岛检测模型并进行了仿真,结果表明改进型算法不仅能快速准确地检测出孤岛,而且减小了检测盲区。

Islanding detection is one of the essential functions for PV grid-connected system, the advantage and disadvantage of the detection performance directly relate to equipment safety.iOn the basis of summing up the current detection methods, aiming at the possibility of failure detection of Slip-Mode Frequency Shift （SMS）, an improved Slip-Mode Frequency Shift （IM-SMS） algorithm is proposed. At first, the working principle of the IM-SMS algorithm is illustrated, then the parameter of IM-SMS algorithm is optimized and non-detection zone （NDZ） is analyzed. In the end, considering the impacts of different local load on islanding detection, Matlab/Simulink is used for setting up 5kW PV grid-connected system, and simulation study is processed afterward. The experimental results show that the proposed method can not only detect the islanding fast and accurate, but also reduce the NDZ.