【摘要】 对近期提出的基于零序直流原理的单分支故障电缆测距模型做了理论分析,提出检测电流的比值与故障电缆距离之间的线性关系,从而消除了电网电压波动和故障电阻对检测电流的影响。考虑到检测电流值很小且容易受外部信号的干扰,进一步将电流比值对故障距离求偏导,指出了减小接地电阻和改变检测电阻值等提高检测精度的措施。在此基础上通过仿真和实验验证了上述理论,揭示了检测电流与故障电缆测距模型中各个参数之间的关系,为进一步构造单分支故障电缆测距算法奠定了基础。更多还原

【Abstract】 The conclusion that the linear relationship between the ratio of detective currents and the location of fault cable is drawn by studying the model of single fault cable location based on zero sequence DC,thereby the effect of the power grid voltage fluctuation and fault resistance on the detective current is eliminated. Considering that value of current is small and easy to be disturbed by external signals,a series of measures such as reducing earthing resistance and changing detective resistance are taken to improve the detective accuracy by the method of partial derivative of current ratio with respect to fault location. Based on this, the theory mentioned above is confirmed by simulations and experiments,which indicate the relations between the detective currents and various parameters of model of fault location cable and lay the foundation for further constructing algorithm of single cable fault location.更多还原