A Comprehensive Thermal Management System Model for Hybrid Electric Vehicles.

Abstract

This study describes the creation of efficient architecture designs of vehicle thermal man-agement system (VTMS) for hybrid electric vehicles (HEVs) by using numerical simula-tions. The objective is to develop guidelines and methodologies for the architecture de-sign of the VTMS for HEVs, which are used to improve the performance of the VTMS and the fuel economy of the vehicle. For the numerical simulations, a comprehensive model of the VTMS for HEVs which can predict the thermal response of the VTMS dur-ing transient operations is developed. The comprehensive VTMS model consists of the vehicle cooling system model and climate control system model. A vehicle powertrain model for HEVs is also developed to simulate the operating conditions of the powertrain components because the VTMS components interact with the powertrain components. Finally, the VTMS model and the vehicle powertrain model are integrated to predict thermal response of the VTMS and the fuel economy of the vehicle under various vehicle driving conditions. The comprehensive model of the VTMS for HEVs is used for the study on the architec-ture design of the VTMS for a heavy duty series hybrid electric vehicle. Integrated simu-lation is conducted using three VTMS architecture designs created based on the design guidelines developed in this study. The three architecture designs are compared based on the performance of the VTMS and the impact of the VTMS design on the fuel economy under various driving conditions. The comparison of three optional VTMS architectures shows noticeably significant differences in the parasitic power consumptions of the VTMSs and the transient temperature fluctuations of electric components depending on the architecture design. From the simulation results, it is concluded that, compared with the VTMS for the conventional vehicles, the architecture of the VTMS for the SHEV should be configured more carefully because of the additional heat source components, the complexity of component operations, and the dependency of the parasitic power con-sumption on driving modes.