Optimization of the in situ Performance of Common Mode Chokes for Power Drive Systems Using Designable Parameters

The selection of electromagnetic interference (EMI) output filters in a power drive system can be a challenge that involves a “cut and try” process with several retro-designed EMI filters, which are often not optimized in term of size, weight, or cost. Key components of an EMI filter are common mode chokes. They are needed to reduce common mode currents which are the main source of radiated emission in power drive systems. Using a “static modification factor,” this paper analyses effects of its designable parameters on its final performance as if it was already in situ. All in situ impedances of the common mode current loop have been taken into account. Two test setups are used to validate effects related to changes of core material, size, number of turns, and wiring system.