Design And Implementation Of High Voltage Generator Control System In Medical X-ray Machine

The main function of high voltage generator is to provide energy for the X-ray tube,which produces X-ray source in the X-ray machine,and its performance will directly affects the performance of the X-ray machine as one of the key components.This thesis mainly discusses the implementation of hardware and software for high voltage generator control system.This paper introduces the basic structure,the working principle,the development history and the development situation at home and abroad for the X-ray machine,and the working principle for high voltage generator,and according to these with the characteristic of medical X-ray machine get the function requirements for high voltage generator control system.The hardware design of control system mainly includes KV closed control,driver of rotating anode and filament.According to application requirements,in order to ensure the accuracy and stability of KV and filament,adopts PI circuit for closed loop control.PI circuit uses the error between setting and feedback as input and uses output to control KV and filament with error amplifier.The driver of rotating anode uses thyristor as AC switch which is triggered by bilateral zero voltage crossing.The hardware circuit also provides peek error of KV signal for system protection function.The control system uses FPGA as the core mainly implements filament control module and rotating anode control module,and these directly affect the stability and accuracy of the system,and on the basis of these analyze and implement the control of exposure.According system requirements implement communication,AD and DA interface module.Finally test the control system,and verify the results of design can meet control requirements.