New vehicle control strategy for fuel consumption and battery state of health improvement in a series hybrid vehicle utilizing fuzzy logic

Abstract

Abstract Series hybrid vehicles have become increasingly popular due to their high efficiency and low fuel consumption. However, the efficiency of a series hybrid electric vehicle largely depends on its control strategy. This paper presents a practical control strategy that optimizes the performance of series hybrid vehicle in terms of fuel consumption. To achieve this objective, the power-follower strategy which uses a fuzzy controller was employed. The combination of the fuzzy controller and the optimal working method for the combustion engine resulted in improvements in fuel consumption and battery state of health. To validate the GT-Power model, experiments were designed and conducted. Three control strategies (thermostat, power-follower, and Max-SOC) were simulated and compared to evaluate the fuel efficiency of the vehicle model. The power-follower strategy led to a 3.7% reduction in fuel consumption compared to the thermostat strategy (currently implemented as the RUNNA strategy), and a 60.1% reduction compared to the Max-SOC strategy. Moreover, using the power-follower method instead of a thermostat prevented frequent charging and discharging of the battery, which is beneficial for improving the battery's state of charge.