Effect of advanced thermal management systems on hybrid electric drive units

In recent years, a significant interest in hybrid electric power unit has arisen globally due to its reliability and efficiency. This paper will discuss the benefits of using advanced thermal management systems in hybrid electric drivetrain, and the different control strategies that can be used to enhance system performance. A detailed one dimensional (1D) simulation model for power split hybrid electric system was developed which consists of three cooling circuits. This model is characterized by a complete modularity and permits the simulation of any new design configuration to investigate the effect of advanced thermal management on system performance. Proportional Integration Derivative (PID) module was used to apply the control strategies. The system behavior has been optimized using Design of Experiment (DoE) method. The simulation results showed a superb fuel economy (4:11) % that solves the problems of high operating costs, also decreasing time of cold start by 50% and increasing the high temperature of the coolant up to 125°C. The motor and generator temperature controlled to the optimum temperature which operate them at the maximum efficiency. These results can be used to be the basis of the final system layout and thermal management strategy.