Power Management Decoupling Control for a Hybrid Electric Vehicle

The control of power flow in a Hybrid Electric Vehicle (HEV) is challenging because of the hybrid structure of the driveline and conflicting performance objectives: fuel consumption minimization, state of charge (SOC) regulation, and drivability. The flexibility and dynamic reconfigurability of modern HEV driveline architectures enable the design of power management control strategies that are able to better address these issues. A decoupling control strategy based on such a driveline model is presented. The driveline has three power sources: an internal combustion engine, an integrated starter alternator, and an electric machine. The power management control strategy consists of a control based upon static minimization of the equivalent fuel cost combined with dynamic control of battery SOC and drivability. By exploiting the structure of the driveline’s dynamic model, decoupling is obtained in the sense that the battery SOC and drivability controls do not affect the power request constraint, nor do they affect each other.