RLC负荷模型分布式发电孤岛检测方法研究

Islanding detection scheme evaluation for RLC load distributed generation

分布式发电系统并网运行时,若主网故障解列断电,就会处于孤岛状态,这是一种危险的不正常的状态。在分析孤岛检测原理的基础上,提出了一种新的检测方法,该法以电网公共节点处电压相位变化与负荷电压变化之比Δ?ΔVL作为判定孤岛发生的指标。在Matlab/Simulink环境下仿真表明新的方法克服了原有被动式检测法在较严苛的功率缺额条件下效果不明显的缺陷,且在电网电压波动,各类型负荷投切等扰动下不会误动作,实现简单可靠,能够迅速检测到孤岛的存在。

In the grid-connection,the distributed system（DS）is on the state of islanding operation if the system is outage after main-grid fault driven spliting.It＇s an abnormal and dangerous state.Based on analyzing the principle of anti-islanding,this paper presents a new method that takes the ratio of phase change to load voltage change,namely on the point of common conjunction as the detection index to judge whether islanding has taken place.In the environment of Matlab/Simulink,simulation indicates the new method can overcome the former defect,that is if the mismatch of power under serious power gap is small,it＇s hard to detect the islanding by using passive detection method.The index will not malfunction on the condition of voltage disturbance,putting into load or load shedding,and detect the existence of islanding rapidly and reliably.