Investigation and Reduction of EMI Noise Due to the Reverse Recovery Currents of 50/60 Hz Diode Rectifiers

Alternating current (ac)/ Direct current (dc) power converters with dc-bus filters can achieve high power density, however, it was found in this article that the reverse recovery currents of the 50/60 Hz diode bridge can lead to significant electromagnetic interference (EMI) noise violating EMI standards above 150 kHz. This article analyzed and quantified the mechanism of the EMI generation due to the reverse recovery currents of the 50/60 Hz diodes. It was found that although the reverse recovery of the 50/60 Hz diode bridge repeats at a frequency of 50/60 Hz, the EMI can be very high above 150 kHz due to the operating principle of electromagnetic compatibility spectrum analyzers. Two techniques were proposed to reduce the EMI due to the reverse recovery of the diode bridge. The analyses were validated by either simulations or experiments.