一种配电线路深度限流型自适应重合闸技术研究

Research on Deep Current Limiting Adaptive Reclosing Technology for Distribution Lines

当传统的配电线路采用的自动重合闸方式重合于永久性故障时,短路电流会对系统及断路器等电气设备造成较大影响,为此提出了一种深度限流型自适应重合闸装置,即在发生故障时投入试探阻抗,利用流过试探阻抗的电流幅值识别故障性质。首先,从阻抗的构成、限流深度,以及瞬时性与永久性故障判定的需求等方面,分析了合理选取试探阻抗阻值的问题。然后,仿真分析了投入试探阻抗时励磁涌流以及负荷低电压脱网对故障识别的影响,实例验证了在合理的试探阻抗阻值下,所提出的方法能够准确识别故障性质,且重合于永久性故障时短路电流不会对系统造成冲击。最后,给出了铁芯电抗器和空芯电抗器这2种试探阻抗的实现方法,通过对比最终选择体积更小的空芯电抗器来设计试探阻抗。

When the traditional automatic reclosing mode is used to reclose in the permanent fault,the short-circuit current will have a great impact on the system,electrical equipment and the circuit breaker.Therefore,a deep current limiting adaptive reclosing device is proposed,that is,put the trial impedance into use when the fault occurs,and identify the nature of the fault by the current amplitude flowing through the trial impedance.From the composition of impedance,the depth of current limitation,and the demand of instantaneous and permanent fault determination,the reasonable selection of resistance value of trial impedance is analyzed theoretically.The effect of inrush current and low voltage release of load on fault identification is analyzed by simulation.The example verifies that the proposed method can accurately identify the nature of the fault under a reasonable test impedance value and coincide with the permanent nature.The short-circuit current will not impact the system when it overlaps the permanent fault.Finally,the realization methods of two kinds of test impedance for the iron core reactor and air core reactor are given.By comparison,a smaller air core reactor is designed to design test impedance.