Modelling of the battery pack thermal management system for Hybrid Electric Vehicles

The Lithium-ion batteries are widely used as energy sources in different hybrid systems, however, the operation characteristics of the battery in such systems are strongly dependent on the operation temperature and therefore, with purpose to improve these characteristics a good thermal control system should be utilized. This paper describes the modelling thermal management system for the battery pack in Hybrid Electric Vehicles (HEVs), which gives opportunity to control the operation temperature of the pack for different load cycles and ambient temperatures. The thermal model of the battery pack is created by using an equivalent electrical circuit with lumped parameters. The thermal control system is created as a combination of the cooling system of the internal combustion engine and the battery pack thermal control system. The heat transfer between these systems is performed by a plate heat exchanger where the inlet flow is controlled by a three-way valve with an electric actuator. Artificial intelligent algorithms together with estimator are applied in control system, with purpose to obtain suitable control properties.