基于多源信息融合的有源配电网故障测距新方法

New Method of Fault Location for Active Distribution Network Based on Multi-source Information Fusion

随着分布式电源以沿线分支的形式接入配电网,忽略分支负荷的传统配电网故障测距方法面临巨大挑战。同时,配电网的测量装置仅在本地能够保证同步,而不同装置之间存在对时误差,给故障测距带来困难。为此,提出一种基于多源信息融合的有源配电网故障测距新方法,综合利用正序电压、电流幅值、有功功率和无功功率实现故障测距。首先,根据光伏电源的控制策略,确定其故障等效模型。其次,根据故障线路的特征,研究故障后各电气量之间的关系。为降低对测量装置同步性的要求,将电压、电流相量进行松弛,得到仅需电压、电流幅值的表达式,然后将故障测距问题转化为优化问题。仿真结果表明,该方法可以准确计算出故障位置,对同步性要求不高,适用于架空-电缆混合线路。

As the distributed generations are connected into the distribution network in the form of branches along the line,the traditional method of fault location for distribution network ignoring the branch loads is meeting great challenges.Also,the measuring devices of the distribution network only keep synchronization locally,but have time synchronization errors between different devices,which brings difficulties in fault locating.Therefore,a new method of fault location for the active distribution network based on the multi-source information fusion is proposed in this paper.It realizes the fault location by making comprehensive use of the positive sequence voltage,the current amplitude,the active power and the reactive power.Firstly,according to the control strategy of the photovoltaic power supply,the fault equivalent model is determined.Secondly,the relationship between the electrical quantities after the fault is studied based on the characteristics of the fault line.In order to reduce the requirement for the synchronization of the measuring devices,the voltage and current phase are relaxed to obtain the expression with the necessary voltage and current amplitude,and then the fault distance measurement is transformed into the problem of optimization.The simulation results indicate that this method can be used to accurately measure the fault locations with low requirements for synchronization,suitable for the overheadcable hybrid lines.