Multi-objective optimization of energy management of a series hybrid vehicle on a highway with solar energy and regenerative braking via NSGA-II

This study presents an optimized multi-source energy management strategy for a series hybrid vehicle integrating an internal combustion engine (ICE), battery storage, photovoltaic panels, and regenerative braking. A multi-objective NSGA-II approach is applied to minimize fuel consumption and CO₂ emissions while enhancing system stability. Under optimization, solar production and regenerative braking curves are smoothed and regularized, indicating improved power integration and energy recovery. The battery state of charge (SOC) remains within safe limits, avoiding deep discharges. Fuel consumption drops 20 % (from 6.5 to 5.2 L/100 km), and CO₂ emissions decrease (160→135 g/km). These gains stem from optimal energy distribution among ICE, photovoltaic (PV) generation, regenerative braking, and battery usage. An optimized proportional–integral (PI) controller and dynamic maximum power point tracking (MPPT) contribute to enhanced stability, especially under highway-like Federal Test Procedure 75 (FTP-75) cycle conditions. Thermal and irradiance analyses underscore the need for adaptive MPPT to manage environmental fluctuations. Overall, the framework yields a 20 % efficiency gain over an urban cycle, meeting propulsion constraints. • Vehicle fuel consumption reduced by ∼20 % via NSGA-II optimization. • CO₂ emissions decreased from 160 to 135 g/km thanks to integrated PV and regen. • SOC remains stable within safe limits, avoiding deep discharges. • MPPT and optimized PI control enhance system stability under real-driving conditions.