Common‐Mode Inductor Design

The common‐mode inductor (CMI) is a very interesting device used to reduce electromagnetic compatibility and electromagnetic interference problems. When considering the performance of an electrical device, it focuses on the differential‐mode voltage and current. Common‐mode voltages and currents can lead to several system problems. The common‐mode current is the sum of the currents in the conductors of the set. It often leads to electromagnetic noise, which can degrade the performance of sensors and cause low‐voltage control hardware to fail. The common‐mode equivalent circuit is a useful tool in understanding a system's common‐mode behavior. The impact of asymmetry is that the differential‐mode currents will create a voltage term in the common‐mode equivalent circuit. The chapter considers the magnetic analysis of the CMI. The CMI current has two components: the differential‐mode current, and the common‐mode current. The chapter develops a design paradigm for the CMI.