煤矿谐振接地系统暂态脉冲特征研究

通过推导煤矿单变电所和多变电所模式下谐振接地系统发生单相接地故障时各支路故障时刻的零序电流表达式,分析了故障线路与非故障线路的暂态脉冲极性关系,以及暂态脉冲的幅度及脉冲宽度与接地电阻、线路对地分布电容和故障时刻之间的关系,并给出了相应的表达式。故障线路的暂态脉冲幅度最大且极性与非故障线路的暂态脉冲极性相反;故障时刻暂态脉冲的幅度与接地电阻成反比,与故障时刻故障相的相位角正弦值成正比;所有非故障线路的暂态脉冲宽度一致,且小于故障线路的暂态脉冲宽度,暂态脉冲宽度与接地电阻成正比。Matlab/Simulink仿真实验验证了理论分析的正确性。

Research of characteristics of transient pulse in coal mine resonant grounding system

By means of deduction of zero-sequence current expressions when single-phase grounding fault occurs in single substation mode and multi-substation mode of coal mine resonant grounding system,polarity relationship between transient pulse of fault line and normal line,and relationships among amplitude or width of transient pulse,grounding resistance,shunt capacitance and fault time were analyzed,and corresponding expressions were given.Polarity of transient pulse of fault line is opposite to the ones of normal lines,and amplitude of the transient pulse of fault line is the largest among all lines.The amplitude of transient pulse at the fault time is inversely proportional to grounding resistance and proportional to sin of angle of fault phase.All the normal lines have the same width of transient pulse,which is smaller than the one of the fault line,and the width of transient pulse is proportional to the grounding resistance. The Matlab/Simulink simulation proves correctness of above theoretical conclusions.