某变电站10 kV系统实测雷电侵入波过电压幅值与波形特征统计分析

雷电过电压是威胁系统安全运行的风险源之一,但目前变电站内雷电侵入波过电压的统计规律尚不明确,难以为绝缘介质的放电特性研究提供广泛数据支撑,造成绝缘配合存在过设计或欠设计问题.该文以某变电站10kV系统实测雷电侵入波过电压数据为基础,研究其幅值和波形参数统计分布规律.研究发现,站内设备上承受的雷电侵入波过电压波形与IEC...

Statistical Analysis of the Amplitude and Waveform Characteristics of Intrusive Lightning Overvoltages Measured From the 10 kV System of a Substation

Lightning overvoltage is one of the risk sources that threatens the safe operation of a power system. However, the statistical laws of intrusive lightning overvoltages in substations are not clear at present. Thus, it is difficult to provide basic data for the study of discharge characteristics of insulation dielectrics, resulting in over-design or under-design of insulation coordination. Based on the measured intrusive lightning overvoltages from the 10 kV side of a substation, the statistical distribution laws of amplitude and waveform parameters are studied in this paper. It is found that there is a significant difference between the intrusive lightning waveform and the IEC standard of 1.2/50 μs double exponential waveform. According to the waveform characteristics of intrusive lightning overvoltages in the substation, the statistical characteristics of overvoltage amplitude, wave front time, dominant oscillating frequency and damping factors are proposed and the probability density distribution is identified by the Kolmogorov-Smirnov(KS) test method. The statistical data show that the amplitude of intrusive lightning overvoltage measured from the 10 kV side of the substation is distributed among [12, 42] kV, and its probability density obeys the Burr distribution. The distribution of wave front time is within [8.3, 167.0] μs and its cumulative probability density obeys the BiDoseResp distribution. The dominant oscillating frequency is distributed among [2.08, 22.22] kHz with an average value of 5.84 kHz, and 99.28% of the oscillating frequency is less than 15 kHz. The probability density of the dominant oscillating frequency obeys the Generalized Pareto distribution. The damping factor of the waveform is distributed among the range of [0.01, 0.90] with an average value of 0.39, and its probability density obeys the Beta distribution. The research results can provide basic data for the study of insulation characteristics, insulation coordination, supporting the data layer construction of the internet of things in power systems.