基于有功功率盲区估计的孤岛检测方法

Islanding detection method based on active power non-detection-zone estimation

分布式发电系统孤岛检测中,被动检测法存在较大盲区,主动移频法可以减小盲区,但影响电能质量。针对上述问题,提出一种基于盲区估计的孤岛检测方法。以负载等效电阻值是否处于有功功率盲区范围作为引入主动移频法的依据,将被动式和主动式结合来进行孤岛判断。该方法能实现无盲区检测,同时降低主动移频法的谐波注入频率,减少对分布式发电系统输出电能质量的影响。通过Matlab建模仿真验证了方法的可靠性,并网逆变器能迅速、有效地检测到孤岛现象。

Passive detection method has a larger blind zone, and active frequency drift （AFD） method can reduce blind zone while the power quality will be lowered in islanding detection of distributed generation system. This paper proposes an islanding detection method based on blind-zone estimation. By determining whether load equivalent resistance is operating in an active power non-detection-zone state or not, the AFD method will be introduced and passive and active detection method will be combined to judge the islanding. The proposed method can realize non-blind zone detection and meanwhile reduce the harmonic injected frequency of AFD method and lower the influence of distributed generation system on output power quality. Matlab simulation shows that the algorithm is reliable, and the grid-connected inverter can detect the islanding fast and effectively.