Robust tracking controller for SEPIC drivers

The non-minimum phase, non-linear nature of the SEPIC (single-ended primary inductor converter) makes it very difficult to get robust operating conditions under load variations. Sliding-mode control method is utilised to design a robust controller for tracking control of SEPIC converters for various applications. The implementation of the method is illustrated with the use pulse-width modulation comparators in the control loop to preclude the risk of modulator saturation and to ease the operations. The performance of the SEPIC converter is investigated through numerical simulation and analogue electronics implementation to show the validity, robustness and feasibility of the proposed controller.