EMI Mitigation Using a Learning-Based Frequency Modulation Carrier in PWM Inverters

Pulse-width-modulation (PWM) inverters generate electromagnetic interference (EMI) due to large dv/dt and di/dt of switching operations. When a periodic carrier is used to generate the PWM control signal, the corresponding EMI spectrum contains strong harmonic components of the carrier frequency. Research has shown that the carrier harmonic spectrum can be mitigated by modulating the carrier frequency. In this paper, we proposed a learning-based method to design the carrier frequency modulation of the inverter by solving an optimization problem, given EMI spectra of the PWM inverter under different carriers as learning data. As a result, a desired EMI spectrum envelop can be achieved according to the EMC regulation. Synthesized EMI results show that our learning-based method generalize the frequency modulation carrier design for EMI mitigation. Experiments provide promising results on EMI reduction.