Evaluation and comparison of a two-level and a multilevel inverter for an EV using a modulized battery topology

Paper in proceeding, 2012

This paper analytically evaluates when it is suitable to use a multilevel inverter in an electrified vehicle. The multilevel inverter is compared to a classical two level inverter for different operation points and for different drive cycles. Reliable models of the components which build up the inverter are needed in order to be able to calculate the losses. Analytical models for the losses are developed to be able to compare the two inverters. Since the two inverters utilizes the battery in different ways the losses in the battery is also considered. It is shown that in certain operation points it is an advantage to use a multilevel inverter to achieve a higher efficiency for the inverter but is also shown that in some operation points the multilevel inverter increases the losses in the battery. However, it is worth mentioning that there is a controllability on where in the battery the losses should take place.The multilevel inverter can also be used as a two level inverter in these operation points to minimize the battery losses.