Finite Element Analysis and Evaluation of Stator Insulation in High Voltage Synchronous Motor

In this paper, two-dimensional finite element analysis (FEA) is used to compute the electric field in stator slot of a synchronous motor. The electrical insulation between the conductors and the edges of slot is evaluated. The relationship between size of air gap and electric field in this air gap is discussed. Secondly the slot-opening electric field, which is not uniform, is calculated by using three-dimensional finite element method. The discussion of insulation structures of slot-opening for anti-corona is conducted. A distributed equivalent circuit model is constructed for the inter-turn insulation under the impulse over voltage excitation. The inductances of the coils are achieved by using magnetic field FEA considering skin effects. The capacitances of the coils are calculated by using electric field FEA and analytic equation respectively. Finally, the evaluation of stator insulation using finite element method is presented.