正反馈主动移频式孤岛检测法分析与改进

Analysis and Improvement of Active Frequency Drift with Positive Feedback Islanding Detection Method

针对传统带正反馈主动移频式孤岛检测方法(AFDPF)的缺点,提出了一种改进方案。该方案在电网正常频率波动范围内仅进行周期性的频率扰动;在孤岛发生时,根据负载性质确定频率扰动方向,采用一种截断系数算法加速频率偏移。实验结果表明:该方案能够加快检测速度,缩小检测盲区,减小对电力系统的谐波污染,完全满足孤岛检测相关标准的要求。

Aim at a traditional active frequency drift with positive feedback(AFDPF), an improved method is proposed. It has a period current disturbance within the normal fluctuation of grid frequency under island happening and a truncated system algorithm accelerates frequency drift.Experimental results verify that the proposed method meets the requirement of anti-islanding standard well, it can detect the islanding operation effectively with faster detecting speed, smaller non-detection zone, and less current distortion from an inverter connected with power system.