The Research On Cooling System Of Traction Converter

With the huge improvement of electrical driving technology for locomotive, the thermal design and control of power electronic components have became more important and more crucial. For traction converter, there is a close relationship between its efficiency and the caloric generating, thermal transferring. Cooling technology is one of the key technologies to enhance traction convector's efficiency. In order to well absorb the state of art cooling technology used by CRH2, setting up the numerical loss model of HVIGBTs for power loss analysis and the CFD simulation model for thermal analysis, are a very efficient and economic methods.At very first, detailed analysis of normal cooling technologies was performed in this paper, by comparing the performance and characteristics between varies cooling principles. There is also a theoretical analysis of cooling system of converter used by CRH2 electrical loco from the perspective of components of cooling system. The cooling method used in CRH2 is called Evaporative cooling techniques in Japanese technical paper. Its principle is very similar with thermosyphon heat-pipe, one kind of heat pipe. Because the thermosyphon heat-pipes have no capillary vessel structure, so they have many advantages like easy-made, cheap and high reliability with high thermal conductivity. For the reasons, the cooling principle of CRH2 converter is analyzed according to the phase cooling principle of thermosyphon heat-pipe in this paper. The phase cooling process of thermosyphon was analyzed in this paper. Based on the general principle of choosing refrigerant, the refrigerants that the CRH2 traction converter uses from the angle of refrigerants' characteristics and concern of environmental protection were analyzed. A new alternative THR02 was introduced in this paper.The second, this paper builds up a physical-mathematical R-C model of HVIGBT modular through experimental research for power loss analysis. The power loss of these modular was calculated according to the actual circuit and condition by using ABB's simulating software.At last, according the calculated power loss, a suitable heat-pipe heat exchanger is designed in this paper. By using the professional CFD software QFIN, the numerical simulations on heat exchanging process of the heat-pipe exchanger under the conditions of various velocities of cooling air and different fin shape were also performed. The simulation results indicated that the heat-pipe exchanger can fulfill on the cooling request of converter.