Cooling System Design Optimization of a High Power Density PM Traction Motor for Electric Vehicle Applications

Abstract

Due to the high power density characteristics of permanent magnet (PM) traction motors and the strict loading conditions of electric vehicle (EV) engine compartments, the excessive losses inside the motors can elevate rapidly the temperature rises, deteriorate the magnetic property of PMs, limit the output torques, and even cause the overheating damages of the machines. In order to guarantee the operational reliability, it's of vital importance to research and develop the effective, reliable and economical cooling systems for improving the working performances of the PM traction motors. In this paper, the three-dimensional (3D) fluidic-thermal coupled model of a high power density interior PM traction motor is established based on the basic theory of computational fluid dynamics (CFD) and numerical heat transfer. The fluid flow and thermal distributions are analyzed based on finite volume method (FVM), and verified by experimental results. According to the heating characteristics of the motor, the external water frame structure of the motor shell is modified to improve the cooling efficiency. Taguchi method is used to optimize the cooling structural parameters, so as to reduce the steady-state temperature rise of the motor. The research work in this paper has certain reference significance for the design and development of high power density PM traction motors used in EV applications.

Recent Developments in Cooling Systems and Cooling Management for Electric Motors

“…The most common technology used to manufacture the housings of such motors is casting using aluminum alloys [137]. The design utilizing an axial arrangement of the ducts decreases the motor's temperature, but the load on the circulation pump is greater due to greater hydraulic losses (pressure drop) in the ducts (Figure 7) [35,102,103]. At the same time, the hydraulic resistance for axial channels is 10-15% higher than that for tangential ones.…”

Experimental Investigation of a Low-Temperature Three-Circuit Cooling System for an Electric Motor under Varying Loads

“…The asynchronous motor is an electric motor that uses electric power to induce rotation of the rotor. 2), the open-type end cover (3), the terminal box (4), the stator (5), the rotor (6), the motor end-plate (7), and the motor fan (8). 2), the open-type end cover (3), the terminal box (4), the stator (5), the rotor (6), the motor end-plate (7), and the motor fan (8).…”

“…The branch of motor engineering has evolved significantly in recent years, yielding a diverse array of motor types and configurations [7,8]. These motors vary in construction, performance capabilities, and resilience to external factors like air temperature and humidity.…”

“…The asynchronous motor of model YE3-250M-4 with power of 55 kW: simplified sketch (a) and photo (b). The components of the motor include the shaft (1), the bearing (2), the open-type end cover (3), the terminal box (4), the stator (5), the rotor (6), the motor end-plate(7), and the motor fan(8).…”

Design and Analysis of a Permanent Magnet Brushless DC Motor in an Automotive Cooling System

“…As motor drive systems are a primary component of NEVs, their performance has a significant impact on NEVs' performance. A motor drive system will continue to accumulate heat during operation [9], and when the system temperature reaches a certain threshold, the system will be exposed to an increasingly hostile environment, wherein the electromagnetic characteristics of the material used in the motor are altered; the residual flux density and coercivity are reduced [10]; the torque capability of the motor is restricted [11]; the power loss is increased [12]; the system's stability and reliability are decreased [13]; and the performance of the drive system is severely limited [14]. In order to prevent these adverse effects, the performance of the cooling system in the motor drive system becomes a particular issue to address.…”