带整流性负载的分布式发电系统孤岛检测研究

为了准确评估孤岛检测的实际性能，在传统的反孤岛测试电路的基础上，给出一种带整流性负载的反孤岛测试电路。利用公共连接点(Point of Common Coupling，PCC)处功率流的规律，得出了功率不匹配度的表达式。在不同的功率不匹配度下，利用该测试电路与传统的测试电路，分别对过/欠压、过/欠频以及电压谐波检测方法进行仿真分析与比较。仿真结果表明，整流性负载的存在会导致过/欠压、过/欠频检测方法的检测盲区(Non-Detection Zone，NDZ)发生偏移，且偏移程度与整流性负载电阻、滤波电容的大小有关；同时，带整流性负载的测试电路是有效和实用的。该测试电路能准确反映孤岛情况下电压谐波的实际响应特性，且电压谐波的大小与整流性负载电阻的大小有关。

Study of islanding detection of distributed generation system with rectifier load

For accurately evaluating the practical performance of the islanding detection, a circuit with rectifier load for the islanding test is proposed based on the conventional test circuit. According to the law of power flow at the point of common coupling (PCC), the expression of power mismatch is obtained. Under different power mismatch, respectively based on the proposed circuit and the conventional test circuit, the detection methods including over/under voltage, over/under frequency and voltage harmonics are analyzed through simulation and comparison. The simulation results show that the rectifier load has made non-detection zone (NDZ) deviate and the degree of deviation is related to the resistor and the filter capacitor of the rectifier load. The results also show that the proposed circuit is valid and practical. It can accurately reflect the actual response characteristics of voltage harmonics when islanding occurs and the voltage harmonics is related to the resistor of the rectifier load.