A Modified Hysteresis-Modulation-Based Sliding Mode Control for Improved Performance in Hybrid DC–DC Boost Converter

Sliding-mode (SM) control is a popular nonlinear control strategy for the dc–dc converters as it offers several advantages such as ease of implementation and robust performance against load and line variations. However, the main drawback of the traditional hysteresis-modulation-based SM controller is that its use in the regulation of the dc-dc converters results in a tradeoff between the overshoot and speed of the closed-loop output voltage response. This is due to the use of the traditional proportional-integral (PI) controller which is used to generate the reference inductor current of the controller. To overcome this problem, the traditional PI-based SM controller is modified such that the reference inductor current used in the sliding surface is now generated using an integral whose integrand is a function of the normalized output voltage error of the converter. A key feature of the integrand is that it is bounded by a user-defined constant. The modified SM control strategy is applied to a hybrid dc-dc boost converter. The expression of the equivalent control signal of the proposed SM controller is derived and the detailed stability analysis of the closed-loop controlled system is given. Also, experimental results are provided to show that the proposed SM controller gives an improved performance as compared to that obtained using the existing PI-based SM controller.