基于零序电流差动量的矿井低压电网选择性漏电保护新方案

A new scheme of selective leakage protection of mine low-voltage power network based on differential variable of zero-sequence current

  • 摘要: 针对现有矿井低压电网选择性漏电保护装置存在可靠性及灵敏度低的问题,提出一种基于零序电流差动量的选择性漏电保护新方案。该方案通过对矿井低压电网发生单相漏电故障时各支路不同采集点的零序电流值做差,根据差动量的幅值及相位在故障支路与非故障支路中的差异性实现漏电保护的横向选择及区段定位。Matlab/Simulink仿真实验及快速傅里叶变换结果表明,该方案不受电网负载容量、三相电源电压初始相位角的影响,在故障选线及区段定位方面具有较高的可靠性及灵敏度。

     

    Abstract: In allusion to low reliability and sensitivity of existing selective leakage protection devices used in mine low-voltage power network, a new scheme of selective leakage protection was proposed which was based on differential variable of zero-sequence current. In the scheme, differential variable of zero-sequence current is gotten at different measured points in each branch when single-phase leakage fault occurred in mine low-voltage power network. Lateral selectivity and fault section location of leakage protection are achieved according to differences of amplitude and phase of the differential variable between fault branch and normal branch. Simulation via Matlab/Simulink and calculation via Fast Fourier caused by Transform show that the scheme avoids influences by load capacity and initial phase angle of voltage of from power network and has high reliability and sensitivity of fault line selection and section location.

     

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