Research On Series Resonant High Voltage DC Power Of X-ray Machine

The discovery of X-ray is extremely important in the natural science and medicine.It is mainly used to detect human diseased organs, convenient for doctors to accuratelylocate in medicine, thus greatly reducing the patient’s pain. X-ray machine at the presentstage itself has defects, such as lower frequency, output voltage range is narrow，bigripple and so on, which affect the performance of the X-ray machine. So study theX-ray machine with excellent performance is extremely urgent.The performance of the X-ray machine high voltage power supply determines theperformance of the X-ray machine itself. The X-ray machine power system in this paperadopted the FM control method to achieve continues changes in the output voltage. Dueto a higher frequency of the FM method is conducive to the development of the X-raymachine to the small and intelligent. The output voltage range is widened, which isbroadened the scope of application of the X-ray machine. The paper made a carfulderivation of the related formulas of the X-ray machine system and simulation isconducted with the Saber software. On this basis through the cooperation with NanjingJie Xiong medical instrument limited company to build an experimental platform. Theexperimental results show that: the experiment is consistent with the simulation, and isbasically to achieve the desired effect.The paper first expounded the X-ray generation mechanism, finding out the keyfactors affecting X-ray machine high voltage DC power supply performance andcarrying out research on this basis.The paper has introduced the basic principles of the PFC circuit, the same time,introduced the interleaved technology briefly which is an emerging technology toimprove power quality and used saber software to simulate the interleaved Boostconverter. The results show that: the interleaved technology has obvious advantages inreducing the current ripple. The paper also introduced the two-phase interleaved PFCcontrol chip UCC28060in detail and solved the PFC problem of X-ray machine highvoltage DC power supply.Full-bridge LLC resonant converter technology adopted by the paper which byadjusting the frequency of the switch to adjust output voltage. However, in order toreduce power supply volume, it is necessary to realize high frequency, then highfrequency caused high switching losses, to this problem this paper introduced the soft switch technology to improve the efficiency of the system. The fundamental harmonicapproximation model of the system is established, gain formula was deduced, and theparameters were optimal designed.The papers finally with the Saber software simulation is conducted for the wholepower system, the results show that by adjusting the switching frequency, the voltagecan be continuous change within40~120kV. In the same time, the experimentalverification of the circuit also shows that using this scheme design of X-ray machinehigh-voltage dc power supply which possessed a high working frequency, wide range ofvoltage regulation, small ripple, etc.