An Improved PWM-Based Sliding-Mode Controller for a DC-DC Cascade Boost Converter

This brief presents an improved pulse-width-modulation- based sliding-mode (SM) controller for the regulation of a 2-stage dc-dc cascade boost converter. The main drawback of the existing SM controller is that its use in the regulation of the high-order dc-dc converter results in a trade-off between the overshoot and speed of the transient output response. In order to overcome this problem, the sliding surface of the proposed SM controller is designed such that the integral action in the resulting equivalent control signal is based on the normalized output voltage error of the converter. Also, the derivative of the inte-grand is bounded by a user defined constant. The derivation of equivalent control signal of the proposed SM controller and the stability analysis of the closed-loop system are presented. Finally, an experimental comparative study involving the proposed and existing SM controllers is provided.