摘要
为解决电压正反馈电流幅值扰动方法中因带入了电压扰动量与电网噪声可能导致系统不稳定的问题,提出了一种简单易实现的电流幅值扰动孤岛检测方法。该方法通过在给定电流波形中加入微小扰动,当孤岛发生时,电流环的跟踪控制作用会使得逆变器输出功率发生变化,进而导致公共点频率发生偏移,实现孤岛检测。文中推导出了电流总谐波畸变率与该幅值扰动因子间的关系,给出了扰动因子的取值范围,仿真结果及与主动移频法的盲区对比,论证了该方法的正确性、可行性和有效性。
This paper proposes an easy and simple current amplitude perturbation method for islanding detection in order to solve the unstable problem of the photovoltaie system caused by the voltage disturbance and power grid noise with the voltage positive feedback current amplitude perturbation method. In the method, a tiny perturbation is added into the given current waveform so that the tracking control action of current loop will change the inverter output power and cause the frequency of PCC （the point of common coupling） to shift when the islanding occurs, thus the islanding detection is implemented. In this paper, the relationship between current THD （total harmonic distortion） and perturbation factor is deduced and the perturbation factor range is given. Both the simulation results and the comparison with NDZ（non-deteetion zone） for AFD（active frequency drift） verify that the method is correct, feasible and valid.
出处
《电测与仪表》
北大核心
2013年第10期28-32,共5页
Electrical Measurement & Instrumentation
基金
广西省自然科学基金资助项目(2010GXNSFA013023)
南宁市科技计划资助项目(20121025)
关键词
电流幅值扰动
光伏系统
孤岛检测
总谐波畸变率
current amplitude perturbation, photovoltaic system, islanding detection, THD
