A Direct Step Down and Step Up AC-AC Converter with Inverting and Non-Inverting Operations

In industry, the ac-ac power conversions are performed by using ac thyristor power controllers. But large total harmonic distortion in source current and lower efficiency have limited their use. Here a new single phase ac-ac converter topology is explained which can produce the non inverting step down (buck) ac output, step up (boost) ac output and inverting buck-boost ac output. All the three outputs can be achieved from a single converter using different switching pattern. This converter combines the operation of non-inverting step down (buck) and step up (boost) converters and inverting buck-boost converter in one topology. And a modification is being given so that all these three modes can be incorporated in a single simulink model. The converter has got six diode- switch pairs, one inductor and two capacitors. This converter has no shoot through problem even when all switches are turned on simultaneously. The simulation of the converter is done with MATLAB /SIMULINK software.