Loss Equalization Strategy of 3L Active Neutral Point Clamped Inverter based on Optimization Algorithm

Active Neutral Point Clamped (ANPC) topology was proposed as the evolution of NPC topology which introduces redundant zero-level states and makes loss redistribution possible. However, the problem of loss balancing hasn’t been well resolved. In this paper, two traditional modulation schemes are discussed, approximate loss and thermal model are constructed and mode rotation strategy based on optimization algorithm is introduced to balance junction temperature of devices. Mode ratio is obtained from optimization corresponding to different modulation degree and power factor angle. Finally, simulation results are presented to prove the effectiveness of the strategy.