| Due to the convenience and comfort, safe and environmentally friendly, urban rail transport has been more widely used in China. Traction converter is the heart of urban rail transit vehicles, and its performance directly affects the power consumption of urban rail vehicles, operating performance, transport capacity and so on. IGBT is widely used as a switching device for its better performance. The application of IGBT makes traction converter further lightweight and small, but it results in the heat of per unit volume increasing. Therefore, electronic device cooling is particularly important.In this paper, traction converters use "heat pipe radiator+traveling air" cooling method. Firstly, the heat generated by IGBTs and other high power devices spreads to cooling substrate. Then the substrate transfers the heat to the heat pipe. The heat is transferred to the cooling fins through the phase changing by the condensation working fluid inside the heat pipe. At last, the heat is transferred out.Firstly, a wind tunnel test platform is built. The velocity while city rail car’s running is simulated by adjusting the wind speed of the funs. In different wind conditions, the average temperature of heat source is measured by galvanic. It is drawn that the temperature of heat source increases with the decreasing of wind speed. But it also meets the cooling requirements that the maximum temperature of heat source does not exceed90℃. And then, the heat pipe radiator of traction converters is numerically simulated using CFD method. The model of the radiator is established utilizing professional thermal analysis software ICEPAK. The temperature profile of heat source is obtained under the test wind speed conditions by simulation. Compared with the experimental results, the error of temperature is within5%.Under the condition that the maximum temperature of the heat source does not exceed90℃, the structure of heat pipe radiator is optimized. The number of heat pipe radiators is reduced from68to48, the number of fins changes to8and the height of heat pipe radiator is reduced to270mm. Although the optimized structure changes a lot, in case of the same speed, the maximum temperature of heat source increases only10℃. Besides, after the structure optimized, the radiator becomes small size, lightweight, low supplies and good economy performance, providing a frame of reference for enterprises. But when the car stops over152s, the maximum temperature of heat source will exceed90℃. So the motor must be shut down to prevent causing more accidents because of the devices’ overheating. |
