SiC逆变器高频脉冲电压对Hairpin绕组绝缘安全的影响分析

In order to solve the problem of insulation damage caused by high voltage stress of Hairpin winding under high frequency and high dv/dt pulse excitation of SiC inverter, the voltage stress calculation and safety analysis of inter-turn insulation of a permanent magnet synchronous machine with Hairpin winding for electric vehicle are carried out in this paper. Firstly, the single-turn equivalent circuit model of Hairpin winding considering the coupling effect of two conductor sides is proposed, the high-frequency distribution parameters of motor winding are extracted, and the inter-turn voltage calculation model of Hairpin winding is established based on the field-circuit coupling finite element method. Then, the inter-turn insulation voltage stress of the windings driven by the SiC inverter is obtained, and the correctness of the model and analysis method is verified by using the inter-turn voltage test platform. Finally, the influences of inter-turn voltage amplitude, insulation thickness, relative dielectric constant of materials and inter-turn air gap length on the distribution line of air gap electric field are analyzed. Based on the relation between the electric field distribution line of air gap and Paschen curve, a method to judge whether the insulation of winding discharges is presented.