计及线路阻抗与负荷影响的不平衡配电网电压消弧方法

在单相接地故障和接地故障消弧的分析中，通常假设配电网是三相平衡的。已有的消弧方法在对地参数和负载不平衡的配电网单相接地故障时消弧效果不佳。针对上述问题，提出一种计及线路阻抗和配电网参数不平衡的电压消弧方法。分析考虑配电网参数不平衡和线路阻抗的配电网等效模型，推导出精确电压消弧指令值，通过故障前后各注入一次电流计算电压指令值，有源消弧装置调控零序电压至该指令值从而抑制故障点电压、电流为0。为了避免任意注入电流引起故障电流增大，将传统电流消弧作为电压消弧的过渡能有效补偿故障电流。通过和已有考虑线路阻抗电压消弧方法、忽略线路阻抗电压消弧方法对比，仿真结果表明，在不同的不平衡度、故障位置和接地电阻下，所提方法消弧性能最佳。

Voltage-type arc suppression method for an unbalanced distribution network considering the influence of line impedance and load

The distribution system is commonly assumed to be balanced in the single-line-to-ground (SLG) fault analysis and ground-fault arc suppression. The existing arc suppression methods are poor in the case of an SLG fault in a distribution network with unbalanced ground parameters and load. To solve the above problems, a voltage-type arc suppression method considering line impedance and distributed parameter imbalance is proposed. The equivalent model of distribution network considering the distributed parameters imbalance of the distribution network and line impedance is analyzed, and the accurate voltage-type arc suppression reference is derived. The neutral voltage reference is calculated by injecting currents before and after the fault. The active arc suppression device regulates the zero-sequence voltage to the reference value, so as to suppress the fault voltage and current to zero. In order to avoid the increase of fault current caused by the arbitrary injection current, the traditional current-type arc suppression is used as the transition of voltage-type arc suppression. This can effectively compensate for the fault current. By comparing the existing voltage-type arc suppression method considering line impedance, the method ignoring line impedance and the proposed method, the simulation results show that the proposed method has the best arc suppression performance under different imbalance degree, fault location and grounding resistance.