A Comparative Study of Supervisory Control Strategies for a Series Hybrid Electric Vehicle

To develop an efficient real-time supervisory control strategy for a series hybrid electric bus, three kinds of popular strategies were compared in principle; backward simulations in ADVISOR were conducted for these strategies. Comparative simulation results shows that thermostat control strategy makes the internal combustion engine operate at its most efficient condition; power follower control strategy is helpful to reduce the battery usage, hence, reduce the power loss associated with charging and discharging and extend the battery life; and the equivalent fuel consumption control strategy proposed in this paper provides a total system optimization between the engine and battery efficiencies, leading to the best fuel economy.