Design of Fuzzy Sliding Mode Controller for DC-DC Converter used in Enhanced Fast Charging of Electric Vehicle

Abstract

In the current automotive landscape, the increasing adoption of electric vehicles (EVs) over traditional fossil fuel vehicles has significantly influenced charging time and infrastructure. Enhancements in the control systems for DC-DC off-board fast charging have become a key area of research in EV technology. These improvements not only boost the overall efficiency of fast charging but also reduce charging time, which consequently enhances the market share of EVs compared to fossil fuel vehicles. The control strategy proposed in this model aims to enhance the performance of the DC-DC converter. Although many conventional controllers are available, they often fall short in providing optimal control for high-frequency switching DC-DC converters in off-board chargers. The advanced fuzzy-based controller is designed to manage the dynamic behaviour and nonlinear characteristics of the converter. Initially, a sliding mode controller was developed using a small-signal state space average model. Based on the converter's behaviour, a fuzzy-based sliding mode controller was introduced to achieve superior performance by mitigating the chattering effect. Finally, the simulation results for the proposed controller, applied in a 400V/120A DC-DC off-board fast charger for an electric vehicle, were analysed and evaluated.