Common Mode EMI Suppression Based on Simulated Annealing Algorithm

Different common mode (CM) EMI suppression methods are discussed and a parallel-connected active CM EMI suppression technique with digital closed-loop control is presented. A novel CM noise evaluation measure based on the energy of CM noise current is proposed. The relationship between the energy of CM noise current and the lead/lag time of compensating current is studied. It is shown that there are multiple local minimums on the relationship curve. Simulated annealing algorithm is used to search for the global minimum of CM noise energy. Simulation results show that CM EMI suppression based on simulated annealing algorithm (SAA) can regulate the phase of compensating current accurately without getting trapped at local minimums, suppress CM noise level effectively, and improve the EMC performance of power electronic products