Control strategy optimization of a hybrid fuel cell vehicle with braking energy regeneration

This paper deals with the optimized control strategy within the vehicle which is driven by a fuel cell stack hybrid with a NiMH battery. The aim is the instantaneous energy management to optimize the hydrogen consumption. At first the powertrain was modeled using data on testbed. Then the optimization control problem basing on an equivalent hydrogen consumption strategy is defined, where the motor target torque and DC/DC target current should be calculated. According to the shift signals and pedal position signals, the vehicle operation can be divided into two modes, non-brake mode (idle, drive backward, drive forward, slide) and brake mode. The optimization problem was solved respectively. Results in ldquoChina typical city bus cyclerdquo testing show the robustness and effectiveness of the strategy in improving fuel economy while maintaining drivability. The fuel economy was improved from 9.6 kg/100 km to 7.9 kg/100 km and the battery SOC was kept around 47%.