Designing the ANPC inverter to increase the starting torque in traction applications

Inhalt:
High inverter efficiency is one of the main aspects in power electronics to improve electric transportation systems. Higher DC-link voltages of electric vehicles are an instrument to reduce losses and charging time. Therefore, three-level topologies like the ANPC inverter are becoming more suitable since they allow the use of lower voltage semiconductors at high DC-link voltages in combination with other advantages like lower THD and fault tolerance. Nevertheless, the ANPC topology has the disadvantage of unequally distributed semiconductor losses. This holds the potential of different optimisation strategies, which influence the behaviour of the inverter. This paper discusses and analyses the most promising optimisation principles concerning their capability to equalise the loss distribution and to increase the starting torque.