Experimental and numerical investigation on a novel heat pipe based cooling strategy for permanent magnet synchronous motors

The boosting electric vehicle industry requires permanent magnet synchronous motors (PMSMs) to possess the characteristics of high power density, high efficiency and high reliability. This requires the motor to bear a higher power within a smaller volume, which results in the increase of heat generation inside the motor and the decrease of effective cooling space. To solve the severe heat dissipation problem of the PMSM, a novel heat pipe based thermal management strategy is proposed in the current study. 3-dimensional heat pipes are introduced into the gap between the winding and the casing, whereas potting silicon gelatin is used to fix the heat pipes and also increase the contact area. The winding temperature rise under a wide range of cooling and working conditions are conducted to evaluate the cooling effect of this heat pipe based cooling strategy. As a comparison, the original motor and the motor only with heat pipes are also included in the tests. The results show that this novel approach maintains the lowest temperatures with a maximum decrease of 22.9 degrees C compared to the original motor, however, there is only 10 degrees C decrease for the motor only with heat pipes. Besides, the stable running time of the PMSM with this novel cooling strategy has increased about 50.6 s under the peak-load condition while the counterpart only with heat pipes almost has no enhancement. Furthermore, a numerical model is established and possesses the capability to coincide well with the experimental data, which paves the way to optimize the proposed heat pipe based thermal management solution.