The Design Of A Dc High-Voltage Power-Supply For X-Ray Tube

X ray is widely used in scientific research, military, and industrial production. The generation of X rays need dc high voltage power supply, which is stable and reliable. The quality of the power supply directly affects the work of X-ray generator. As the developing of the power devices, control devices, and the new control strategy, the dc high voltage power supply is developing in the direction of the high-frequency, modular and intelligent.Based on X-ray tube on the performance of the dc high voltage power supply, this paper designed a dc high voltage power supply, which uses DSP as controlling chip, adjustable voltage within a certain range of size and having low ripple. The hardware designing of the power supply mainly includes AC/DC converter and DC/DC converter. Firstly, the220v mains were rectified by the active power factor correction (APFC) circuit, the output was about400v dc voltage, and then through the DSP controlling the duty-cycle of the driving PWM in the Buck circuit, lowered the400v dc voltage to the required size, which is the bus voltage of the inverter circuit. DSP output two complementary, with a dead band time controled of the phase shift PWMs to control the inverter circuitand converts the dc bus voltage to ac square wave voltage, which is promoted by a high frequency transformer and voltage doubling rectifying circuit to the required of the dc negative high voltage. Samped the output voltage,then compared with the reference voltage, DSP according to the size of the error adjust the driving PWM’s duty-cycle, realize the stability of output voltage. The power system can be linear adjusted in the range of40kv to80kv by setting the value of the reference voltage.Finally, using the Saber software simulation verify the feasibility of the power supply system, which provides the basis for the job of the circuit’s testing and improving.