15. Performance Evaluation of Fast Charging DC–DC Converter for Electrical Vehicle with Root Locus-Based Digital Controller

In recent times, because of range anxiety, charging time and charging infrastructure of electric vehicles (EVs) are the main subjects to wide gap in research and development. Charging station infrastructure plays a major role in easy transition from traditional IC engine-based vehicles to EVs. The implementation of off-board fast charging for EVs with proposed control strategy aimed to facilitate the improved performance of a DC–DC converter. However, there are many analog controllers proposed in controlling converters, which lack in optimum operation of high-frequency DC–DC converter. Digital controllers provide optimum control not only in case of static input voltage but also in case of change in input voltage. At first step, pole–zero mapping is used in designing the small signal-based discrete-time model of the desired DC–DC converter. Based on discrete-time modeling, digital controller is designed using root locus technique. Lastly, simulation results are acquired for a 400 V/120 A DC–DC converter, which is used in fast charging system of electric vehicle. The analysis of the proposed controller design is presented in detail.