光伏电站接入配电线路单相接地故障分析

Fault Analysis of Single-phase-to-ground Fault in Feeders Connecting with PV

针对光伏电站接入中性点经电阻接地配电线路后,配电网单相接地故障特征发生显著变化即电网侧故障电流增大、光伏侧短路电流因受控而受限的问题。结合光伏电站控制策略进行单相接地故障分析,利用叠加原理和三序网络推导出电网侧和光伏侧三序电流,得到光伏侧零序电流不受光伏控制器控制策略影响、电网侧检测不到零序电流并且负序电流显著增大的故障特征。最后,用Matlab/Simulink仿真验证了所开展故障分析的正确性。

After the PV is connected to the resistance grounded distribution line through the neutral point,the single-phase-to-ground hase grounding fault characteristics of the distribution network change significantly:the fault current on the grid side increases,and the short circuit current on the PV side is limited due to the control.Based on the control strategy of photovoltaic power station,the single-phase-to-ground hase grounding fault analysis is carried out,and the grid side and photovoltaic side three sequence current are derived by using the superposition principle and three sequence network.The fault characteristics that the photovoltaic side zero sequence current is not affected by the control strategy of photovoltaic controller,the grid side cannot detect zero sequence current,and the negative sequence current significantly increases are obtained.Matlab/Simulink simulation verifies the correctness of the fault analysis.