基于多电容接地方式的低压直流微电网故障定位

Fault Location for Low-voltage DC Microgrid Based on Multi-capacitor Grounding Scheme

为提高低压直流微电网故障定位的准确性,提高电力系统运行的可靠性,提出一种基于多电容接地方式的低压直流微电网故障定位方法。首先,运用从馈线端子和接地电容器获得瞬时电流和电压,推导了直流微电网一般故障馈线的数学模型。其次,利用基于非线性优化方法的故障测距算法对故障及相关故障电阻进行了精确定位,并通过评估接地电容器在故障期间的响应,计算故障的准确距离。最后,通过搭建直流微电网实验室模型对所提方法的可靠性及有效性进行验证,实验结果表明所提方法具有较高的故障定位准确性。

To improve the fault location accuracy of low-voltage DC microgrid and the operation reliability of power sys⁃tem,a fault location method for low-voltage DC microgrid based on a multi-capacitor grounding scheme is proposed.First,a mathematical model of general fault feeder in DC microgrid is derived according to the instantaneous current and voltage obtained from feeder terminals and grounding capacitors.Second,the fault location algorithm based on the nonlinear optimization method is used to accurately locate the fault and the related fault resistance,and the accurate fault distance is calculated by evaluating the response of the grounding capacitor under the fault.Finally,the reliability and effectiveness of the proposed method are verified by building a DC microgrid laboratory model,and experimental re⁃sults show that this method has a high fault location accuracy.