Active EMI Suppression with Adapted Cancellation Signals for a Buck Converter in Varying Modes of Operation

Abstract:
Many modern power electronic systems make use of fast switching semiconductors for energy conversion and distribution. Steep switching slopes for high efficiencies may cause high levels of electromagnetic emissions. Conducted emissions are conventionally reduced by applying heavy and bulky passive filter components. The basic concept of active filtering aims at a destructive interference between the emissions (noise) and a generated anti-noise signal and is one idea to overcome the disadvantages of passive filter components. In this contribution, a self-adapting, FPGA-based active EMI cancellation system using artificially synthesized cancellation signals is investigated for the first time during a buck converter’s transient changes in operation.