Harris Hawks optimization based sliding mode control of high voltage-gain DC–DC converter in electric vehicle onboard chargers

Purpose This paper aims to focus on developing a sliding mode controller (SMC) to enhance the dynamic performance of a high voltage gain bidirectional DC–DC converter. Design/methodology/approach The Harris hawks optimization (HHO) approach is used in determining the SMC variables to address the limitations in practical implementation of SMCs. For extending the lithium-ion (Li-ion) battery pack’s lifecycle in an electric vehicle, a constant current–constant voltage (CC–CV) charging strategy is adopted. Traditional CC–CV methods are prone to switching transients during mode transitions, resulting in higher switching losses and shorter battery life. This study addresses this issue by executing a real-time simulation of CC–CV charging and achieving a smooth transition between modes using the HHO-SMC approach. The transient and steady-state characteristics of the bidirectional converter is studied for both operation modes. To investigate the efficacy of the controller, real-time simulation and experimentation are carried out on a hardware-in-the-loop (HIL-402) real-time emulation platform. Findings Test results validate the effectiveness of sliding mode control in the charging and discharging performance of the bidirectional DC–DC converter. Better load regulation features in terms of settling time undershoot and overshoot are provided by the optimal SMC. Originality/value This study provides a structured design methodology for SMC with the aid of the HHO algorithm, which resolves the practical difficulties in implementation of SMC. To assess real-world circumstances, this study uses HIL emulator, an emerging technique for developing automotive controllers.