Research On DC-DC Converter With Parallel Current Sharing Mode At High Temperature

With the development of power electronics technology,power electronic circuits are more and more widely used in many fields,such as petroleum and natural gas industry,automobile industry,aviation industry and so on.These areas require a circuit system to work reliably in a high temperature environment.However,the high temperature is the main reason for the poor reliability of electronic equipment.How to improve the normal and reliable operation of electronic equipment in high temperature environment is regarded as one of the key technologies.In order to improve the reliability of DC-DC converter parallel system in high temperature environment,the parallel system of DC-DC converter in high temperature environment is studied in this paper.When the power capacity is the same,the parallel power system has a lot of advantages compared to a single power supply system,such as high efficiency,redundancy and so on.When the power system works in the high temperature environment,these advantages can improve the stability and reliability of the system.However,when the sub modules are connected in parallel to form a parallel system,the problem of current sharing between parallel sub modules must be solved.In this paper,we study the parallel system of DC-DC converter at high temperature.First of all,this paper discusses the common DC-DC converter parallel system of the current sharing method.The output impedance method is chosen as the current sharing method after the comparison of the advantages and disadvantages of various methods.Then,the small signal model of the DC-DC converter parallel system is simulated based on the output impedance method and the two methods are implemented: the series resistance method and the output current feedback method.The advantages and disadvantages of the two methods are compared and the output current feedback method is more suitable to be used as the current sharing method.Finally,the output current feedback method is used to design the DC-DC parallel system.The feasibility of the scheme is verified by simulation and it is verified that the proposed scheme can solve the problem of current sharing in DC-DC parallel system at high temperature.