Optimal Control of Energy Flow between Electrified Auxiliaries and Powertrain in Hybrid-Electric Heavy-Duty Vehicles

Predictive control strategies are state of the art in hybrid vehicles today. In this contribution, an optimal control strategy for a 48V powernet of a heavy-duty long-haul truck is investigated. A holistic approach is presented to control the power supply of actuatable electrified auxiliaries along with the common hybrid-electric driving functions. As a consequence, numerous state-control-combinations have to be calculated. To handle this computational effort the presented method utilizes heuristic information about the driven route. Thereby, the route is segmented into classes of related power demand. Subsequently, Dynamic Programming is applied to solve the optimal control problem. As example for an electrified auxiliary the compressor of the air-condition is chosen. A baseline control strategy for a reactive 48V system is compared to the optimal solution based on simulations. The features and use cases of the optimal control are discussed. It will be shown that applying the optimal control approach for the 48V system with knowledge about the whole route results in additional benefit in fuel consumption.