Common Mode Voltage Cancellation in Integrated Modular Motor Drives

Increasing switching transition slopes and miniaturizing of power electronic set-ups lead to more problems due to electromagnetic interference (EMI). This paper presents a concept to suppress the electromagnetic disturbances in modular electrical drives without using common mode filters. The usage of full bridge converters enables the synchronization of the switching transitions to suppress the emitted common mode disturbances of every single module. To evaluate the concept, the parasitic paths of a single module are investigated. With consideration of the parasitic paths, an accurate EMI model is built which identifies improvements for the cancellation concept in future applications. Finally, the concept and the simulation model are verified by measurements.