In order to ensure the safe operation of the mine power grid, reduce cable ground accidents, and solve the problems of real-time monitoring of the insulation of coal mine power cables, a new method of cable insulation "quasi real-time monitoring" is proposed.The influence of the range and precision of mutual inductor on proposed algorithm are separately discussed during the load operation and no-load running period.At last, the simulation results are verified by using MATLAB.The results show that:combining with the actual situation of power network in coal mine,a WAMS program is used to control the high-voltage cable for shot term no-load operation and to collect current, voltage value, and calculate insulation resistance of cable to ground.Then the "quasi real-time" monitoring of the cable insulation condition can be accomplished.The method can accurately measure the insulation conductance (resistance) value and tanδ value of the cable within certain range.Therefore, it is feasible to use this method to monitor cable insulation condition.
