基于柔性调控零序电压的不平衡配电网故障检测方法

柔性消弧过程中实现故障选线、过渡电阻测量与故障性质判定对现有配电网单相接地故障检测具有重要意义。针对配电网三相对地参数不对称的柔性接地系统，首先分析不平衡零序电压对消弧效果的影响，提出柔性消弧全补偿电流的计算方法。然后分析正常运行状态下和单相接地故障状态下注入电流和母线零序电压之间的约束关系。结果表明：无论系统处于何种状态，均可通过改变注入电流来柔性调控母线零序电压，进而调控各线路零序电流。并根据柔性调控零序电压前后各线路零序电流的变化规律，提出一种可实现故障选线、过渡电阻测量和故障性质判定的故障检测方法。Matlab/Simulink仿真验证了该方法的有效性和准确性。

Fault detection method for unbalanced distribution networks based on flexible regulation ofzero-sequence voltage

It is important to realize fault line selection, transition resistance measurement and fault property determination in the process of flexible arc suppression for single-phase grounding fault detection in the existing distribution network. Considering a flexible grounding system with asymmetric three-phase ground parameters in a distribution network, first, the influence of unbalanced zero-sequence voltage on arc suppression effect is analyzed, and a calculation method of full compensation current for flexible arc suppression is proposed. Then, the constraint relationship between the injected current and the bus zero-sequence voltage in normal operation and in single-phase grounding fault is analyzed. The results show that no matter what state the system is in, the bus zero-sequence voltage can be flexibly regulated by changing the injected current, and then the zero-sequence current of each line can be regulated. According to the variation law of zero-sequence current of each line before and after flexible regulation of zero-sequence voltage, a fault detection method that can realize fault line selection, transition resistance measurement and fault property determination is proposed. The effectiveness and accuracy of the method are verified by Matlab/Simulink simulation.