Combined with actual situation of Fengxian power Supply Company, the neutral grounding modes of Fengxian 35 kV and 10 kV power grid are studied in the paper. The different frequencies injected method is used to measur...Combined with actual situation of Fengxian power Supply Company, the neutral grounding modes of Fengxian 35 kV and 10 kV power grid are studied in the paper. The different frequencies injected method is used to measure the capacitive current of Fengxian 28 substations, and the neutral grounding modes of the 28 substations are determined based on the measured values of capacitive current.展开更多
When, in a coal mine distribution network whose neutral point is grounded by an arc suppression coil (ASC), a fault occurs in the ASC, compensation cannot be properly realized. Furthermore, it can damage the safe and ...When, in a coal mine distribution network whose neutral point is grounded by an arc suppression coil (ASC), a fault occurs in the ASC, compensation cannot be properly realized. Furthermore, it can damage the safe and reliable run of the network. We first introduce a three-phase five-column arc suppression coil (TPFCASC) and discuss its autotracking compensation theory. Then we compare the single phase to ground fault of the coal mine distribution network with an open phase fault at the TPFCASC using the Thévenin theory, the symmetrical-component method and the complex sequence network respectively. The results show that, in both types of faults, zero-sequence voltage of the network will appear and the maximum magnitude of this zero-sequence voltage is different in both faults. Based on this situation, a protection for the open phase fault at the TPFCASC should be estab-lished.展开更多
针对某市10 k V配电网中性点运行方式存在的问题,提出一种结合中性点经电阻接地和经消弧线圈接地的优化改造方案。用ATP-EMTP建立10 k V配网单相接地故障仿真模型,在两种不同中性点接地方式下,模拟多种单相接地故障。理论分析及仿真实...针对某市10 k V配电网中性点运行方式存在的问题,提出一种结合中性点经电阻接地和经消弧线圈接地的优化改造方案。用ATP-EMTP建立10 k V配网单相接地故障仿真模型,在两种不同中性点接地方式下,模拟多种单相接地故障。理论分析及仿真实验表明,该新型接地方式可有效抑制单相接地时刻的瞬态过电压,当接地故障发生于架空线末端时,中性点、母线和故障点上的瞬态过电压降幅分别为34.7%、25.3%和18.5%;同时,该新型接地方式能够避免虚幻接地现象发生,并且在发生永久性单相接地故障时,可以通过切换并联电阻以实现准确的故障选线。该新型接中性点地方式对于配网安全可靠运行具有重要意义。展开更多
文摘Combined with actual situation of Fengxian power Supply Company, the neutral grounding modes of Fengxian 35 kV and 10 kV power grid are studied in the paper. The different frequencies injected method is used to measure the capacitive current of Fengxian 28 substations, and the neutral grounding modes of the 28 substations are determined based on the measured values of capacitive current.
文摘When, in a coal mine distribution network whose neutral point is grounded by an arc suppression coil (ASC), a fault occurs in the ASC, compensation cannot be properly realized. Furthermore, it can damage the safe and reliable run of the network. We first introduce a three-phase five-column arc suppression coil (TPFCASC) and discuss its autotracking compensation theory. Then we compare the single phase to ground fault of the coal mine distribution network with an open phase fault at the TPFCASC using the Thévenin theory, the symmetrical-component method and the complex sequence network respectively. The results show that, in both types of faults, zero-sequence voltage of the network will appear and the maximum magnitude of this zero-sequence voltage is different in both faults. Based on this situation, a protection for the open phase fault at the TPFCASC should be estab-lished.
文摘针对某市10 k V配电网中性点运行方式存在的问题,提出一种结合中性点经电阻接地和经消弧线圈接地的优化改造方案。用ATP-EMTP建立10 k V配网单相接地故障仿真模型,在两种不同中性点接地方式下,模拟多种单相接地故障。理论分析及仿真实验表明,该新型接地方式可有效抑制单相接地时刻的瞬态过电压,当接地故障发生于架空线末端时,中性点、母线和故障点上的瞬态过电压降幅分别为34.7%、25.3%和18.5%;同时,该新型接地方式能够避免虚幻接地现象发生,并且在发生永久性单相接地故障时,可以通过切换并联电阻以实现准确的故障选线。该新型接中性点地方式对于配网安全可靠运行具有重要意义。
