Reversible unity power factor step-up/step-down AC-DC converter controlled by sliding mode

A reversible step-up/step-down AC-DC converter is presented in this paper. It is a fifth-order system, capable of managing power transfer from a DC source to an AC one, with any ratio between the DC and the AC voltage levels, and producing a sinusoidal output current, using only one power processing stage. By reversing the energy flow this circuit becomes a high power factor rectifier. This reversion can be obtained simply by inverting the reference AC current. The system is analyzed as the connection of two independent lower order subsystems, controlled by sliding mode with decentralised switching scheme. Experimental results from a 100 W prototype operating in both senses, as inverter and as rectifier, are shown to confirm the mathematical analyses and simulations.