ABSTRACT
This chapter describes pulse width modulation (PWM) technique. The three-phase voltage source PWM converter, also called voltage source inverter, can perform the connection between the DC side and the AC side of a source/load coupling. In PWM techniques based on zero-sequence signal injection, the voltage linearity, the waveform quality, and the switching losses are strongly influenced by the choice of the zero-sequence signal. On the basis of these considerations, many researchers have investigated high-performance PWM techniques, among which the so-called discontinuous PWM (DPWM). DPWM is also called two-phase space-vector modulation and is a particular kind of carrier-based technique, where the zero-sequence signals are added in such a way that only two phases are switched at the same time. Closed-loop PWM techniques with real-time optimization tend to be used mainly in high-power industrial and traction AC drives, where power devices are predominantly thyristors or, at increasing powers, even GTOs.
