基于电网阻抗测量的新型主动式孤岛检测法

对一种针对单相并网系统的基于电网阻抗测量的主动式孤岛检测方法进行了深入分析。详细阐明了该检测方法的检测盲区,绘制了检测盲区分布图。新型孤岛检测法通过在参考电流相位中加入一个幅值很小的二倍频扰动信号,检测电网阻抗变化实现反孤岛保护。具有实现简单、对电能质量影响小、理论上几乎不存在检测盲区、响应时间短、抗干扰性好、可测量网侧阻抗并可用于多台逆变器并网系统等优点。在并网变换器实验平台上对该方法进行了实验验证,实验结果表明其检测性能优越,满足IEEE929-2000标准。

A New Active Islanding Detection Method Based on Specific Frequency Impedance Measurement

A new active islanding detection method based on specific frequency impedance measurement was studied, whose impact on the grid current and Non-Detection-Zones (NDZ) was analyzed in detail. A NDZ mapping method was characterized. Each cycle of the converter current reference was slightly modified by an injected signal thus affecting the generated current in a negligible way. When the grid becomes unavailable, the grid impedance moves outside of a preset threshold value. The method was promised smaller disturbance and near no Non-Detection-Zones. In addition, the method was highly robust to different grid disturbances and stiffness, and was effective for multiple inverters running in parallel. The new anti-islanding method was successfully tested on an experimental setup to meet the standard requirements of IEEE 929-2000.