Next Generation Thermal Management System Control Architecture for Battery Electric Vehicles

Abstract

The global automotive sector is experiencing a rapid transition towards electrification due to increasing concern over global warming and stricter emission regulations. Battery Electric vehicles (BEVs) play a central role in this transition. The efficiency and reliability of BEVs largely depend on the thermal behavior of various temperature-dependent components like battery pack, electric motor, and power electronics. The thermal management system (TMS) must not only balance the cooling and heating of temperature critical components, but also ensure passenger comfort by regulating the cabin temperature as per the need.

There are several TMS architectures used in the automotive application. The key focus of this study will be investigating the performance of Full Secondary Loop (FSL) architecture which uses propane-based refrigerant and water-glycerol as coolant. The investigation in this project has been done using the Complete Vehicle Thermal Modelling (CVTM) simulation environment at Volvo Cars, which is a GT-Suite based one-dimensional (1D) thermal-fluid model that represents the physical FSL hardware.

The study focuses on investigating the effectiveness of the FSL architecture in controlling the temperature of battery, electric drivetrain and cabin temperature in an energy efficient manner by studying the effects of operating parameters of various actuators present in a TMS like pumps, valves, radiator fan and compressor. A control strategy has also been developed based on the requirements for cooling of the battery, electric drivetrain or cabin and the operating parameters of the controllable actuators.

The results demonstrate that a properly designed FSL system can effectively regulate the temperatures of critical components and the cabin, and also identifies the optimal operating parameters necessary for efficient system performance.