Study on corona discharge of winding cables in linear motor

The distribution cable was often used as armature winding in modern high voltage motor. The electric field in windings was distributed more evenly and the insulating property of motor was then advanced by use of winding cable. But corona discharge may still exist in this kind of cable winding motors. The model of single phase winding cable and linear motor stator was built firstly. The electric field of cable in stator slot and near the outlet of stator slot was analyzed. In addition, we studied the end-region electric field of linear motor. Based on the electric field distribution, the possible sites were analyzed where the corona discharge may firstly occur. The research results indicate the electric field was distorted near the outlet of stator slot and end region of motor, and the field intensity was increased here. At the same time, when the cable sheath was not well contacted with the ground system, corona discharge may occur. So near the outlet of stator slot, end-region of motor and bad grounding spot of cable shield the corona discharge will first occur. At last we discussed some ways to decrease the probability of corona discharge in linear motor.