Design And Implementation Of Downhole High-Temperature DC Switching Power Supply

Power supply refers to the device that supplies energy to electronic devices.All electronic devices cannot work without power.Switching power supply has become one of the most widely used power supply equipment due to its small size,high power density and good stability.With the continuous development of human society,surface oil and gas resources are gradually depleted,and deep oil and gas resources will become an important energy replacement field in the future.The increasing depth of the well makes the underground temperature higher and higher,this puts higher requirements on the temperature adaptability of the switching power supply.Moreover,with the development of semiconductor technology,the popularity of SiC power devices capable of stable operation over a wide temperature range provides more possibilities for the design of high temperature switching power supply.Based on a downhole switching power supply project,this paper designed a wide input dual output switching power supply module that can work stably in the environment of 0?150?.The whole process of high-temperature switching power supply design was introduced in this paper.Firstly,according to the design index of the project,the most suitable flyback topology was selected and the power circuit that can meet the temperature requirement was designed.Then the control scheme at high temperature was found.The control circuit and drive circuit were designed,and the power supply problem of control part was solved by using auxiliary winding power supply and designing high-temperature start-up circuit using capacitor divider.Finally,in order to ensure the stability of the output voltage,an isolated feedback circuit at high temperature was designed,mainly including the design of the circuit for primary feedback and the design of the system compensation network.And on this basis,completed the design of the high temperature transformer.Based on the design,the PCB was drawn and soldered,and the whole power module was debugged.Then the indicators of the power module were tested at room temperature(30?)and high temperature(150 ?).Finally,it passed the 48-hour full load uninterrupted work test at 150?.Through the analysis of the test results,it is verified that the performance of the power module can meet the project requirements and can work stably for a long time at high temperatures.