State of the art PWM techniques: A critical evaluation

With the introduction and wide acceptance of gate turn off power devices (e.g. Bipolars, Power Fets, GTO´s, etc.), the switching behavior of converters has reached the point where further improvements in firing and switching networks bring only marginal benefits. Consequently, the research interests in the area of static converters have been shifting toward improving the process of power conversion through a combination of new circuit topologies and improved voltage and harmonic control PWM techniques. As a result several such techniques have been proposed lately.