Design Of 140KV High-Voltage DC Power-supply For X-ray Tube

X-ray has been widely used in industry and medicine since it was found in 1895.However,the low-freuency transformer and multiple voltage rectifiers were used to generate the DC high-voltage for X-ray tube from 50Hz-AC utility system.These conventional types of X-ray sources were bulky in physical size and heavy in weigh and the control accuracies of the output voltages were not always satisfactory.The development of a high-frequency X-ray source using switching power-supply technology and digital control technology is discussed in the paper.The introduction part carries out a brief introduction on the background of the subject.The paper investigated the principle of generating X-ray and the V-I character of X-ray.At last,the paper elaborates the subject source and the main work of this paper.In chaper 2,hardware of power supply is presented.Firstly,the whole structure diagram and general work process is given.Secondly,the design of HVDC power supply and filament power supply is presented.The design of HVDC power supply include the selection of circuit topology,the principle of half-bridge converter,PWM formation and control circuit,power drive circuit,high-frequency transformer and snubber circuit,bi-directional double circuit, voltage feedback and voltage adjusting circuit,overcurrent protection and current adjusting circuit and working power supply circuit.The design of filament power supply base on DPA-Switch.The last part of this chaper the paper introduce the desigh of high-frequency transformers and the choice of main components.In chaper 3 introduce power starting control circuit and system software part.single-chip control the filament power to start(to closed) after receiving opening(closed) signal from the remote circuit.Delay circuit starts HVDC power supply after filament has heated 8s,to realizing the remote boot of HVDC power supply. Through data acquisition and conversion circuit, voltage and current value of HVDC and filament power supply of LCD Dsiplay based on single-chip.The whole software system is programmed with C language and is divided into two parts,and they are:analog/digital conversion and the model of LCD.At last,a test through examples shows that the system can obtain satisfactory results.The main features of this system:(1)The system will use high-frequency technology in the design of high-voltage power supply,futher reduces the volume of high-voltage power supply.(2)the use of bi-directional double circuit greatly reduce output high-voltage rippe.(3)The system combine switching power supply technology and single-chip microcomputer control technology, to realizing the remote boot of HVDC power supply.