带电压频率正反馈的主动移频式孤岛检测方法-电力系统保护与控制.PDF

第42 卷 第 8 期 电力系统保护与控制 Vol.42 No.8 2014 年4 月 16 日 Power System Protection and Control Apr.16, 2014 带电压频率正反馈的主动移频式孤岛检测方法 蒋 翠，祁新梅，郑寿森 （中山大学电力电子及控制技术研究所，广东 广州 510275 ） 摘要：主动移频式孤岛检测 (Active Frequency Drift Method, AFD)算法简单、有效，但由于给电流施加了扰动信号，所以 输出的电能质量受到影响，同时它的检测盲区 （Non-Detection Zone, NDZ ）也较大。对 AFD 算法进行了改进，采用电压频 率正反馈，且电流扰动量为改变部分电流幅值的方法。分析了孤岛检测的总谐波特性，采用Qf 0 Cnorm 坐标平面对改进算法 的检测盲区进行了描述。仿真实验表明，与传统的主动移频式孤岛检测算法相比，改进的孤岛检测算法提升了检测速度，改 善了电能质量，并有效地减小了检测盲区。 关键词：孤岛效应；总谐波分析；检测盲区；孤岛保护；仿真分析 Active frequency drift islanding detection with positive feedback of voltage frequency JIANG Cui, QI Xin-mei, ZHENG Shou-sen (Institute of Power Electronics Control Technology, Sun Yat-sen University, Guangzhou 510275, China) Abstract: Active Frequency Drift (AFD) Method is a simple and effective islanding detection method. However, the power quality is affected due to the introduced distortion on inverter current and the non-detection zone is bigger. This paper proposes an improvement to AFD by adopting positive feedback of voltage frequency and changing part of the current amplitude rather than changing the current frequency directly. The total harmonic distortion is analyzed and non-detection zone of the improved algorithm is described by using Qf 0 Cnorm coordinate plane. Analysis and simulation show that compared to traditional method, the improved one has less distortion on inverter current, smaller non-detection zone and better power quality. Key words: islanding; analysis of total harmonic distortion (THD); non-detection zone (NDZ); islanding protection; simulation analysi