基于MPPT改进型孤岛检测算法

Improvement of islanding detection method based on MPPT

文章提出了基于MPPT的改进型孤岛检测算法,该算法通过增大Boost升压电路的占空比D,减小光伏输出电压和逆变器输出有功功率,在电网断电时影响并网点的电压,使其超出过/欠压保护阈值,从而检测出孤岛状态。文章充分考虑了本地负载与分布式光伏发电系统的有功匹配情况,消除了检测盲区,增加了扰动周期,进而降低功率损耗,减小对电能质量的影响。对算法进行了仿真和试验,表明该算法符合IEEE Std.929-2000规定。

As the existing islanding detection method based on MPPT have non-detection zone, large power loss and other issues, an improved islanding detection method based on MPPT is proposed. This method is based on increasing the duty ratio D of boost circuit, reducing the output voltage and the output active power of the inverter. Influence of public point voltage when grid outage, beyond its over/under voltage protection threshold, thereby detecting the islanding state. In this paper, the active matching of local load and distributed PV system is fully considered, the non-detection zone is eliminated. This algorithm increases the disturbance period, thereby reducing the power loss and the impact on power quality. According to IEEE Std.929-2000, the results of simulation and experiment show that the proposed algorithm is correct and effective.