光伏、燃料電池、風力等分布式發電系統需要并到電網才能更方便被利用。為了避免分布式發電系統在孤島情況下運行，本文提出了一種基于功率控制的孤島檢測方法，這種方法使分布發電系統提供不斷變化的無功功率，同時檢測公用連接點（PCC）的電壓和頻率。當孤島發生時，被測頻率將發生變化，連續觀察4個周期，被測頻率仍然出現變化，則降低分布發電系統有功功率為原來的80%后再觀察，如果被測電壓下降則認定為孤島，可安全斷開分布式發電系統。該方法算法簡單，并在MATLAB仿真驗證。
Abstract: Dispersed power generation systems such as photovoltaic, fuel cell, wind power generation need to be connected to a utility power grid for the systems to work effectively. In order to avoid the negative impacts from islanding operation, a novel islanding detection method based on Power Controlling is presented in this paper, The method continuously perturbs the reactive power supplied by dispersed generation systems while simultaneously monitoring the point of common coupling (PCC) voltage and frequency. If islanding were to occur, a measurable frequency deviation takes place, After it is over 4 cycles continuously, then the real power of dispersed generation systems is reduced to 80%, now a drop in voltage positively confirms islanding, and the dispersed power systems is safely disconnected. Algorithm of the method is simple and confirmed by simulation with MATLAB.
關鍵字：孤島 分布式發電系統 無功功率干擾
Keywords: Islanding; Dispersed power generation systems; Perturbs of the reactive power.