含光伏电源的配电网故障定位策略研究

摘要

基于监测电压暂降的配电网故障定位逐渐成为研究热点，同时随着智能配电网的发展，光伏电源越来越多的接入配电网。光伏电源的接入使传统的辐射型配电网的网络结构发生变化，且光伏电源的故障电流特性与同步发电机不同，使得基于电压暂降的配电网故障定位方法运用于含光伏电源的配电网时会产生较大误差。为了解决含光伏电源配电网的故障定位问题，基于低电压穿越控制策略针对光伏电源的短路电流特性进行了分析，然后介绍了含光伏电源的配电网故障电流的求解算法。通过遍历搜索候选母线，确定使得电气故障后故障电压实测值与理论计算值最为吻合的母线和故障类型，从而确定故障最邻近的母线。基于对IEEE34节点配电系统改造后的算例进行计算仿真，验证了文章方法应用于含光伏电源配电网定位的正确性和有效性。%Fault location of distribution network based on monitoring of voltage sag has become a hot research topic. Meanwhile, with the development of smart distribution network, photovoltaic power ( PV) is gaining more and more applications, which changes the structure of traditional radial distribution network a lot.The characteristics of PV fault current are different from the synchronous generators.Therefore, the fault location based on monitoring of voltage sag will bring large error when applied in distribution network with PV.In order to solve the problem of fault location for distribution network systems with PV, fault current characteristics of PV is studied with a control strategy for low volt-age ride through ( LVRT) .Then, the calculation method of fault voltage of distribution network with PV is put for-ward.The theory of fault locating proposed is to search the assumed fault bus which makes the fault voltage measured is in agreement with the calculation value.Then the bus which closest to fault position is obtained.Finally, a case study based on IEEE-34 node system is conducted to prove the correctness and effectiveness of the proposed method.