考虑光伏低电压穿越特性的交流微电网保护方法

微电网内部发生故障时,采用恒功率(PQ)控制的光伏电源会进入低电压穿越状态,导致微电网线路电流的相位发生改变,进而可能造成故障方向判别错误.因此,对光伏低电压穿越状态下输出电流相位进行分析,然后对母线上的故障电压分量和故障电流分量的相位特性进行分析,提出了一种基于3组正序电流相位比较的故障方向判别方法.PSCAD/EM...

AC microgrid protection method considering photovoltaic low voltage ride through characteristics

When fault occurs in the microgrid, the PV(PhotoVoltaic) generation adopting constant power control(PQ control) will enter the LVRT(Low Voltage Ride Through) state, which will lead to the phase change of the microgrid line current and cause the fault direction discrimination error. Therefore, the phase of the output current in the PV LVRT state is analyzed, then the phase characteristics of the fault voltage component and the fault current component on the bus are analyzed, and the fault direction discrimination method based on phase comparison of three groups of positive-sequence currents is proposed. The simulative results by PSCAD/EMTDC verify the effectiveness of the proposed method.