Research On Dynamic Switching Technology Of Power Module Of DC Charging Equipment

As the fossil fuel consumption led to the increasingly serious environmental problems,electric vehicles as a new energy vehicles promoted by governments of many countries.DC charging equipment can make a quick supplement of electric power for electric vehicles,its research and development for the application and popularization of electric vehicles has a great role in promoting.Since a large amount of power modules are used in the DC charging device to output DC power in parallel,the output current of each power module is reduced due to the smaller current required by the EV in the later stage of charging,which leads to low utilization of the power module,Equipment charging efficiency is not high.In order to solve such a problem,this paper designs a power module dynamic switching device,which is used to switch the excess power module in the late stage of charging into a new charging process,and keep only a few power modules to provide the required current.The key technologies such as high-power,low-loss switching devices,temperature control,important device protection,and dynamic switching control strategy involved in dynamic switching of power modules are analyzed.The problems encountered in the implementation of these key technologies are analyzed in detail,and the corresponding solutions are given,which provides the basis for the design of the power module dynamic switching device.The power module dynamic switching device has been designed.The design of the driving,control and protection circuits in the power module dynamic switching device is completed.At the same time,the corresponding control software is designed and the general framework of the working flow chart and the program of the control software is given.Aiming at the problem of large heating value of the power devices in the dynamic switching device of the power module,the thermal design was carried out and the thermal simulation has been conducted to verify the rationality of the thermal design.The prototype production and experimental platform set up.The temperature measurement experiment and charging experiment were carried out on the experimental platform to verify the cooling effect of the cooling design and the power module dynamic switching device to enhance the efficiency of power module utilization and device charging efficiency.