基于频数分布理论的矿井供电系统故障选相

Fault phase selection of mine power supply system based on frequency distribution theory

针对矿井不对称中性点不接地系统发生高阻接地时选相效果不佳的问题,提出了一种基于频数分布理论的矿井供电系统故障选相方法。该方法采集故障后各相电压首个1/2工频周期的数据,然后采用扩展Prony算法拟合采样数据,再应用频数分布理论处理各相电压的采样数据,在此基础上利用贝塞尔公式求出各相电压的频数分布值,通过比较频数分布值大小选出故障相。Matlab仿真与适应性分析结果表明,所提选相方法准确率高,适用于低阻接地与高阻接地的故障状况,对噪声干扰和数据窗长度有较强的适应性,同时不受采样频率和组距的影响。

In view of the problem of ineffective selection of asymmetric mine neutral point ungrounded system while high resistance grounding occurs,a fault phase selection of mine power supply system based on frequency distribution theory was proposed.Each phase voltage after the fault of the first 1/2 frequency cycle was collected,and extended Prony algorithm was used to fit the collected data,then the frequency distribution theory was used to process the sampled voltage of each phase.On the basis,frequency distributions of voltage of each phase were obtained by Bessel formula,and the fault phase was selected by comparing the magnitude of the frequency distribution.The results of Matlab simulation and adaptability analysis show that the proposed method has high accuracy and is applicable to fault conditions of low impedance grounding and high impedance grounding.It has strong adaptability to noise interference and data window length,and is not affected by sampling frequency and group distance.