Development Of The 350 KV High Voltage DC Power Supply For X-ray Tube Base Of DSP

X-rays has been widely used in modern industry,scientific research,medical imaging,production and live.However,there is an obvious gap in X-ray machine between our country and abroad,especially in the high-performance X-ray tube and the high voltage power supply.This work studied the high voltage power supply of X-ray tube that used in industrial nondestructive testing,which goal is to achieve a maximum of 350 kV/20 mA output,with DSP as the control system of the digital high voltage DC power supply,and voltage stability is 0.5%,ripple coefficient is 0.01%.This paper introduces the principle of X-ray tube and the research status of high voltage power supply both in domestic and overseas in the first part.Combine with the characteristics of a modern high voltage power supply,the main structure of power supply was designed,which takes the three-phase AC as input,and achieves DC high voltage output through rectifier and filter,full bridge inverter,transformer booster and voltage doubling rectifier.Then in the control system part,some basic information like the SPWM control theory,PID control method and the characteristics of control chip TMS320F28377 S was introduced.The program flow diagram was designed and the system control program was compiled in the CCS software to achieve the SPWM output wave of control site.In the following low voltage part,the structure selection and theoretical design of the rectifier filter circuit,full bridge inverter circuit and relevant auxiliary circuit.This circuits are simulated by MATLAB/Simulink and the PCB board designed by Altium Designer,the experiment terrace is set up and it can achieve stable work.In the last high voltage part,the high frequency transformer and voltage doubling rectifying circuit were designed.Based on the calculation of high-frequency transformer iron core and winding parameters,ANSYS is used to simulate insulation problems of the high frequency transformer,the winding of the electric field between the layers,and a high frequency transformer with an output of 60 kV was designed.Through the analysis of the characteristics of common doubling rectifier circuit,a six times the pressure of the positive and negative two-way the CW voltage doubling rectifying circuit was designed,and its capacitance parameters were calculated and simulated,the optimum value of voltage doubling capacitor is 0.1uF.According to the size of voltage doubling capacitor for the circuit design and simulation,and circuit structure can meet the requirements of safety work be verified.