A Sliding Mode Control Method for SEPIC Power Factor Correction Converter

A sliding mode control method is proposed in order to solve the problems of SEPIC power factor correction (PFC) converter under conventional PI control, such as the difficulty of parameter design to balance the dynamic and steady performance simultaneously, great impact on output by the load changes. As a control method for nonlinear system, sliding mode control has the advantages of being insensitive to system parameter changes and disturbances and high robustness. In this paper, based on the analysis of discontinuous conduction mode (DCM) circuit operation mode, combined with indirect sliding mode control theory, a sliding mode control method for SEPIC converter to realize PFC is proposed. The simulation model was established through PLECS platform while the feasibility and advantages of applying this control method to the SEPIC PFC converter are verified by comparing the circuit performance with the conventional PI control.