An optimal design of the coolant channel across the stator core of the permanent magnet motor

Abstract

For avoiding the damage of the insulation and permanent magnet, the temperature rise of the PMSM (permanent magnet synchronous motor) should be controlled strictly, it is usually one of the main objectives during improving the output power and torque density beyond the state-of-the-art in motor design. In this research, the coolant channel will be placed within the yoke of the stator core to enhance the heat transfer between the stator core and the coolant. Hydrophobic coating is applied to replace the metal tube for increasing the utilization of the cross area of the coolant channel. The impact of the coolant channel on the performance of the permanent magnet motor is analyzed. A general design method of the coolant channel is presented. The result shows that the change of the stator core loss is within about 10% as the coolant channel is moved away from the slot along the radial direction while the back electromotive force of the motor could keep constant through appropriate design. The impacts of the coolant channels on the magnet performance and the heat dissipation performance could be divided completely with the design method. The method can be applied on various PMSM including SPM (surface-mounted permanent magnet motor) and IPMSM (interior permanent magnet synchronous motor). Sufficient coolant flow could be provide to help conduct the temperature rise of the motor.