An Enhanced PWM Scheme of Three-Level T-Type Inverter for Loss Balance and Reduction

The unbalance loss distribution of the three-level (3-L) T-Type inverter increases the cost and reduces the overall reliability. A novel loss-balance modulation scheme is proposed for 3-L T-Type inverter in this paper. With the proposed modulation scheme, the switching loss and conduction loss of all switches in the 3-L T-Type inverter can be balanced respectively regardless of the power factor and modulation index. This method is independent of the power factor and the modulation index, and only the on-resistance of devices are required. With the proposed method, the total loss of the inverter can also be reduced, and the neutral point potential can be balanced naturally. The proposed modulation scheme is validated in a 200 kW SiC-based 3-L T-Type inverter.