Analysis of dead-time effects in a five-phase open-end drive with unequal DC link voltages

In this paper, pulse width modulation (PWM) of a five-phase multilevel open-end winding drive with two inverters supplied with unequal dc-link voltages is analysed. In particular, the effects of dead time on the drive performance are discussed. They are a consequence of PWM switching of both inverters at the same time, which happens to be an inevitable part of the modulation strategy. Detailed analysis of this phenomenon is presented and one possible solution is suggested. This solution is entirely based on changes in the modulation strategy, so that changes in the drive topology and hardware are not required.