Complete Characterization of EMI for ECMs with PEEC Method

The method of partial element equivalent circuit (PEEC) is employed to characterize the electronically commuted motor (ECM) systems by incorporating the parasitic effects of power traces in the PCB layout. The PEEC method is used to identify PCB parasitics in the electronic controller of ECM using Method of Moment (MoM) based electromagnetic simulator, ANSYS Q3D. The performance of the complete electronic controller system is simulated by including these parasitics in the controller circuit using Ansys Simplorer. It is confirmed that parasitics in the PCB layout contribute to voltage overshoot on the power device during regular switching operations and particularly during transient conditions such as output short-circuit. The simulation results are subsequently optimized to comply with FCC's Electromagnetic Interference (EMI) limits. The system is then measured for Common Mode (CM) and Differential Mode (DM) noise for EMI and results are compared with the simulated results, with agreement verified.