Study of the Factors Affecting the HV Protection of Air-conditioning Units in Railway Passenger Cars
It is common for the air-conditioning units of railway passenger cars to fail when they are running in hot weather in the summer.Through fault investigation,cause analysis and ground test verification,it is determined that the main factors causing the HV protection fault of the air-conditioning unit are high external environment temperature,solar radiation,attenuation of condensing air volume and unreasonable setting of triggering conditions of the electromagnetic bypass valve of the air-conditioning unit.To solve the above problems,the control logic of the electromagnetic bypass valve in the air-conditioning unit is optimized,and the action of the electromagnetic bypass valve is controlled by evaluating the high pressure of the refrigeration system by using the compressor current value.This can improve the high-temperature resistance of the air-conditioning unit.According to the safety principle,setting the redundant number of pressure switch actions within the safety allowable range of the compressor can ensure the comfort of people in the vehicle.The test demonstrates that the optimized scheme can effectively resolve the high-voltage protection issue of air-conditioning units.
万方数据
维普
