基于功率控制的分布式并网发电孤岛检测研究

光伏、燃料电池、风力等分布式发电系统需要并到电网才能更方便被利用。为了避免分布式发电系统在孤岛情况下运行，本文提出了一种基于功率控制的孤岛检测方法，这种方法使分布发电系统提供不断变化的无功功率，同时检测公用连接点（PCC）的电压和频率。当孤岛发生时，被测频率将发生变化，连续观察4个周期，被测频率仍然出现变化，则降低分布发电系统有功功率为原来的80%后再观察，如果被测电压下降则认定为孤岛，可安全断开分布式发电系统。该方法算法简单，并在MATLAB仿真验证。
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.
关键字：孤岛 分布式发电系统 无功功率干扰
Keywords: Islanding; Dispersed power generation systems; Perturbs of the reactive power.