MPC-Based EMS for a Series Hybrid Electric Tractor

Abstract

This paper presents a model predictive control (MPC) based energy management system (EMS) using a multi-objective optimization problem. The proposed scheme design utilizes four primary energy management objectives: power sharing, SOC regulation, fuel consumption minimization, and engine efficiency maximization. Secondary objectives of energy management are also discussed, such as battery degradation and temperature. The proposed algorithm is validated in a tractor performing a cultivator and a baler drive cycle. Its performance is compared against that of a rule-based (RB) EMS. The implementation is performed in a real time simulation platform OPAL-RT. It was observed that the proposed MPC-based EMS achieved a good trade-off between the primary objectives, while it also improved the battery temperature and battery degradation as compared to the RB EMS results. In particular, during the cultivator cycle, the fuel consumption and fuel economy were improved 12.17% and 11.64%, respectively, while the battery temperature got 16% lower, and the battery degradation was reduced by 56.19%. Meanwhile, during the baler cycle, the fuel consumption and the fuel economy were improved 4.81% and 5.55%, respectively, while the battery temperature got 23% lower, and the battery degradation was reduced by 78.94%.