Analysis of dead-time effects in multi-phase voltage source inverters

Inverter dead-time effects have been investigated in past for three-phase voltage source inverters. Also, there have been some studies about multi-phase (more than three phase) inverters with reference to multi-phase drives. Recently, a great deal of research has concentrated on PWM methods suitable for multi-phase VSIs. All PWM methods theoretically produce sinusoidal output voltages without low-order harmonics. This paper analyzes the dead-time effects on output variables of voltages source inverters if no any compensation technique is applied. In particular, an overview of three-phase inverters is considered first. Then, a generalized extension to multiphase inverters is proposed and investigated in details. Theoretical analysis has shown that particular low-order harmonics appear as result of dead-times, and simulation results confirm the proposed analytical approach.