Concurrent and Simple Controller for AC/DC Power Converters - Theoretical Design and Experimental Evaluation

The problem of controlling PWM AC/DC power converters is considered. The focus is made on a class of full- bridge boost rectifiers commonly referred to power factor correctors. We seek both output voltage regulation and power factor correction. These are achieved thanks to a cascade control structure involving two loops. The inner loop acts on the switching device so that the input current tracks a sinusoidal reference that is in phase with the supply network voltage. The outer loop modulates the amplitude of the current sinusoidal reference so that the converter output voltage tracks its reference. The above loops involve simple PI regulators together with suitable variable changes. The controller thus obtained turns out to be simple and can be implemented by analogue hardware. The performances of the resulting closed-loop are theoretically analysed and experimentally evaluated.