Calculation and measurement of the capacitance between stator frame and slot conductors and its influence on common-mode current

An electrostatic simulation of a single stator slot using finite-element method was made in order to calculate the capacitance between stator winding and stator frame. Additional calculations of the capacitance were made, where the slot conductors were dislocated from their original position, which resulted in higher capacitance. The simulation was confirmed with measurements. Both were performed on the example of the in-wheel direct drive motor. Common-mode current transient phenomenon, caused by inverter switching operation, was simulated.