High-frequency induction machine models for calculation and prediction of common mode stator ground currents in electric drive systems

For the calculation of the common mode (CM) ground current in voltage source - inverter fed induction machines a simplified (SHF) and a distributed (DHF) high-frequency equivalent circuit are compared. The SHF circuit needs measured parameters of the electric machines, but gives good results in comparison to the measured CM ground current. The DHF circuit predicts the CM currents purely from calculated HF motor parameters in 2D FEM analysis and is more complicated. The CM currents and HF winding impedances of a 7.5 kW and 240 kW motor are presented.