Design Of Hard Pulse Power Supply System For Magnetron

At present,the magnetron is widely used in microwave generator,particle accelerator,medical and health fields.With the increasing requirements of magnetron power supply system in the X-ray machine and CT machine for medical equipment,such as in power level,modulation waveform,efficiency,life and volume.The traditional pulse modulator uses the boost transformer power supply method combined with the modulation switch of hydrogen thyratron,which has many shortcomings,such as poor output waveform,complex regulation and control method,serious heating,and fewer discharge times,so it cannot meet the requirements.With the continuous development of power semiconductor technology and microprocessor technology,high efficiency,high power and long life have become the mainstream development direction of pulse modulator.An All-solid-state pulse modulator can effectively solve the drawbacks of the traditional modulator.Solid-state modulator has the advantages in compact size,flexible control,high efficiency,more precision and good pulse waveform.It is widely used in medical,environmental governance and material research,and has broad development and application prospects.In this paper,a portable hard pulse power supply system is designed for X-band magnetron based on silicon carbide type metal-oxidesemiconductor field-effect transistor(Si C MOSFET)and a novel winding pulse transformer.The main research works are shown in the following:1.According to the technical parameters of the magnetron system and the working characteristics of the load,the overall technical scheme of the hard pulse power supply system is designed,and the specific scheme of the main subsystems is given.2.A new type of winding pulse transformer is designed.To prove that the new winding pulse transformer is better than the traditional ones,the electromagnetic field distribution of the pulse transformer under different conditions is simulated by Maxwell electromagnetic field software.A hard modulator is designed based on Si C MOSFET and fast recovery diode,and the influence of parasitic parameters on the output waveform is simulated by Saber circuit software to verify the performance of the hard modulator.3.The hardware circuit and software of the system are designed,including the schematic diagram and main program flow chart of the control system,charging power supply,hard modulator and filament power supply.4.The experimental verification of the functional prototype is completed,and the key experimental waveforms are obtained.The output pulse voltage amplitude is 11.5k V,the current amplitude is 3.3A,the rise time is 280 ns,the fall time is 200 ns,and the load pulse power amplitude is about 38 k W.Finally,the system simulation and experimental results show that the technical scheme of the system is better than the traditional scheme,which has reference and guiding significance for the engineering research.