In the distribution network system with its neutral point grounding via arc suppression coil, when single-phase grounding fault occurred near zero-crossing point of the phase voltage, the inaccuracy of the line select...In the distribution network system with its neutral point grounding via arc suppression coil, when single-phase grounding fault occurred near zero-crossing point of the phase voltage, the inaccuracy of the line selection always existed in existing methods. According to the characteristics that transient current was different between the fault feeder and other faultless feeders, wavelet transformation was performed on data of the transient current within a power frequency cycle after the fault occurred. Based on different fault angles, wavelet energy in corresponding frequency band was chosen to compare. The result was that wavelet energy in fault feeder was the largest of all, and it was larger than sum of those in other faultless feeders, when the bus broke down, the disparity between each wavelet energy was not significant. Fault line could be selected out by the criterion above. The results of MATLAB/simulink simulation experiment indicated that this method had anti-interference capacity and was feasible.展开更多
针对现有配电网有源电压消弧方法未充分考虑线路电压降落以及分布式电源接入的影响,发生单相接地故障时无法保证故障点电压为0,存在无法可靠消弧的问题,提出了一种考虑分布式电源接入的配电网有源电压消弧技术。首先,在接入分布式电源...针对现有配电网有源电压消弧方法未充分考虑线路电压降落以及分布式电源接入的影响,发生单相接地故障时无法保证故障点电压为0,存在无法可靠消弧的问题,提出了一种考虑分布式电源接入的配电网有源电压消弧技术。首先,在接入分布式电源的基础上,考虑线路的电压降落,推导消弧电压理论计算公式,提出改进有源电压消弧方法。其次,提出一种基于馈线终端设备(feeder terminal unit, FTU)量测数据的数据驱动测距方法,能够在故障发生后准确计算出故障距离,为消弧线圈的控制提供数据。最后,通过仿真证明所提方法相较于传统有源电压消弧方法,能够更好地控制故障点电压为0。展开更多
文摘In the distribution network system with its neutral point grounding via arc suppression coil, when single-phase grounding fault occurred near zero-crossing point of the phase voltage, the inaccuracy of the line selection always existed in existing methods. According to the characteristics that transient current was different between the fault feeder and other faultless feeders, wavelet transformation was performed on data of the transient current within a power frequency cycle after the fault occurred. Based on different fault angles, wavelet energy in corresponding frequency band was chosen to compare. The result was that wavelet energy in fault feeder was the largest of all, and it was larger than sum of those in other faultless feeders, when the bus broke down, the disparity between each wavelet energy was not significant. Fault line could be selected out by the criterion above. The results of MATLAB/simulink simulation experiment indicated that this method had anti-interference capacity and was feasible.
文摘针对现有配电网有源电压消弧方法未充分考虑线路电压降落以及分布式电源接入的影响,发生单相接地故障时无法保证故障点电压为0,存在无法可靠消弧的问题,提出了一种考虑分布式电源接入的配电网有源电压消弧技术。首先,在接入分布式电源的基础上,考虑线路的电压降落,推导消弧电压理论计算公式,提出改进有源电压消弧方法。其次,提出一种基于馈线终端设备(feeder terminal unit, FTU)量测数据的数据驱动测距方法,能够在故障发生后准确计算出故障距离,为消弧线圈的控制提供数据。最后,通过仿真证明所提方法相较于传统有源电压消弧方法,能够更好地控制故障点电压为0。
