How to suppress common-mode noise in EPS inverter circuits?

The high dv/dt generated by the EPS inverter bridge switching action will form a common-mode displacement current through the parasitic capacitance between the power devices and the heat sink. The key to suppressing this current lies in providing a high-frequency, low-impedance return path and blocking its outward conduction. Connecting a common-mode inductor in series at the inverter output is a crucial measure, as it provides high impedance at high frequencies to impede the flow of common-mode current. Depending on the EPS's power rating, for example, CM-L or CM-Z series common-mode inductors can be selected, effectively attenuating noise through the common-mode suppression effect of their cores. Simultaneously, connecting a Y capacitor in parallel between the DC bus and the chassis provides a legitimate, short-distance return path for common-mode noise. Optimizing the drive waveform to reduce the switching voltage change rate can also reduce common-mode noise generation at its source.