Temperature Field Analysis and Cooling Structure Optimization for Integrated Permanent Magnet In-Wheel Motor Based on Electromagnetic-Thermal Coupling

Abstract

Aiming at the impact of heat generation and temperature rise on the driving performance of a permanent magnet (PM) motor, taking the PM in-wheel motor (IWM) for electric vehicles as an object, research is conducted into the temperature distribution of the electromagnetic–thermal effect and cooling structure optimization. Firstly, the electromagnetic–thermal coupling model considering electromagnetic harmonics is established using the subdomain model and Bertotti’s iron loss separation theory. Combined with the finite element (FE) simulation model established by Ansoft Maxwell software platform, the winding copper loss, stator core loss and PM eddy current loss under the action of complex magnetic flux are analyzed, and the transient temperature distribution of each component is obtained through coupling. Secondarily, the influence of the waterway structure parameters on the heat dissipation effect of the PM-IWM is analyzed by the thermal-fluid coupled relationship. On the basis, the optimization design of waterway structure parameters is carried out to improve the heat dissipation effect of the cooling system based on the proposed chaotic mapping ant colony algorithm with metropolis criterion. The comparison before and after optimization shows that the temperature of key components is significantly improved, the average convection heat transfer coefficient (CHTC) is increased by 23.57%, the peak temperature of stator is reduced from 95.47 °C to 82.73 °C, and the peak temperature of PM is decreased by 14.26%, thus the demagnetization risk in the PM is improved comprehensively. The research results can provide some theoretical and technical support for the structural optimization of water-cooled dissipation in the PM motor.

In-Wheel Motor Drive Systems for Electric Vehicles: State of the Art, Challenges, and Future Trends

“…In [87] investigated the effect of flow-rate of the cooling water to optimize the electromagnetic performance of the motor. The thermo-fluid coupling method is used in [88] to analyze the effect of water channel structure parameters on the heat dissipation of the PM in the IWM shown in Figure 13. Based on this analysis, the parameters of the water channel structure are optimized with the suggested chaoticmapping ant colony algorithm using the metropolis criteria to improve the heat dissipating efficiency of the cooling system.…”

Design of a Four-Wheel Steering Mobile Robot Platform and Adaptive Steering Control for Manual Operation

“…Vertical steering enables a steering angle exceeding 90 • , allowing for independent wheel rotation for turning in place and horizontal movement. However, it presents challenges such as occupying upper space due to the steering motor, limited power, increased control complexity, reduced durability, and difficulties in thermal management of in-wheel motors [15][16][17]. Horizontal steering, on the other hand, utilizes a single actuator to transmit power to the axles instead of in-wheel motors.…”

Tangential Electromagnetic Force Array on the Vibration and Noise of Electric Axle for New Energy Vehicle

“…In the 1990s, with the application of permanent magnet motors, the electromagnetic vibration and noise of PMSMs were analyzed [2][3][4]. In recent years, with the development of numerical simulation techniques and test equipment, the vibration and noise of PMSMs have been studied extensively, e.g., the multi-physics field calculation of the radial electromagnetic force on the vibration and noise of permanent magnet motors is used [5]. In [6] to [8], the vibration and noise have been improved by suppressing torque ripple through magnet offset, stator-rotor core surface slotting and magnetic flux barrier optimization, respectively.…”