A Robust Voltage Control of DAB Converter With Super-Twisting Sliding Mode Approach

Abstract

This article presents a supertwisting sliding mode control (ST-SMC) for the isolated dc-dc bi-directional dual active bridge (DAB) power converter for enhanced output voltage regulation. The sliding mode control (SMC) is well-known for its robustness and improved dynamic performance for a nonlinear system. However, it includes the drawback of chattering and degradation of tracking performance. Here, the suggested ST-SMC scheme incorporates the advantages of a sliding mode controller and subsequently eliminates the problem of chattering. The average model of DAB under single phase-shift modulation is considered for controller design, which simplifies the design process. Thus, improved dc-link voltage stability and high robustness for accurate reference voltage tracking are obtained. Further, the proposed scheme provides a robust control for parameter uncertainties as well as the steady-state output voltage contains less ripple when compared to the classical SMC and proportional-integral controller. The experimental results for a 2 kW DAB converter are provided to validate the effectiveness and the robustness of the proposed strategy.