Sliding mode control of PFC converter

Abstract

The controllers in Power Factor Corrected (PFC) converters are conventionally designed in frequency or time domain using linearized model of the converter system. These controllers are not always adequate for PFC converters due to presence of hard nonlinearity in the system. Theoretically, linear feedback designs can only ensure stability and satisfactory operation under restrictive operating conditions for which the linearized model is valid. However, as the application base of PFC converters increases, the need for more robust control schemes becomes imperative. To this end, the sliding mode approach, described in this work, inherently addresses hard nonlinearity present in the PFC converters. The controller design and simulations results are presented and discussed in detail. As expected, the results show that sliding mode controller improves converter dynamics and large-signal stability without compromising on the intrinsic simplicity of the conventional control scheme. The sliding mode controller is found to be more robust and appropriate control scheme for PFC converters as compared to conventional linear controllers.