Comparative evaluation of PWM AC-AC converters

Recently a new family of AC-AC power converters has been proposed for AC power conditioning. They are solid state functional equivalents of transformers with a continuously variable transformation ratio. Operating on the principle of pulse width modulated control using gate turn off devices like IGBTs, they have been shown to have significant performance advantages compared to older generation thyristor based phase controlled power converters. The family of proposed converters include buck, boost, buck-boost and Cuk power converters. This paper is aimed at presenting the design guidelines and the results of a comparative study of these power converters. Detailed design equations are provided along with a typical examples of design of various power converters for a power conditioning application