Investigation of winding schemes by slot-based high-frequency modelling of a hairpin winding stator

The winding insulation system of inverter-fed electrical machines is exposed to electrical stress due to unpredictable transient overvoltages. The voltages in the μs range happen with fast switching inverters and high DC link voltages. These high-frequency voltage overshoots can cause partial discharges and further lead to severe damage to the machines’ insulation systems, bearings which result in a reduction of their lifetime. In the present study, a high frequency hairpin stator lumped parameter model in a slot-based domain was developed and the influence of a winding scheme on such overvoltages was investigated. The parameters for the model have been calculated analytically or were derived from impedance measurements. The generation of simulation models with different winding schemes was automated and a beneficial winding scheme was determined.