Research Of Microwave Power Supply And Control Technology Of 915MHz Magnetron

915MHz magnetron is widely used in the fields of civil heating,medical treatment,smelting,meteorology,power plant and so on,being it's ability of more output power.Three-phase boost transformers and rectifiers are used in the traditional 915 MHz magnetron power supply.It has large volume,low efficiency and low input power factor and the control method of the power supply is relatively simple and lack of necessary protection measures.The control system which can overcome the above shortcomings is very rare in our country,so it is very important to do the research of power supply and control technology.In this paper,the anode high voltage power supply and the system control method of CK-611 magnetron are focused on.Its rated oporation voltage of 12.5kV and the maximum rated current of 2.8A.In this paper,Firstly,the research status and driving power of 915 MHz magnetron control methods are summarized,in the same time the control structure of the whole system is determined.Secondly,the anode high voltage power supply of magnetron is designed.The research focuses on the VIENNA rectifier.It can be controlled by using three level technologies,which greatly reduce the influence of harmonics of the power supply system,compared with the conventional PWM rectifier at the same number of switches.Three level full bridge LLC resonant is used in the inverter design.It can increase the power density and reduce the negative impact of the transformer leakage inductance.It ensures a highinput power factor and efficiency,at the same time,the control timing of the magnetron and the control strategy of the output power are studied by using the TMS320F2812 controller.Finally,in order to verify the design of the circuit and its control method,the Simulink simulation software and experiments are used to verify the two aspects.The 5kW anode high voltage power supply and its control system are tested.The experimental results show that the anode high voltage power supply designed by VIENNA rectifier and the three level full bridge LLC resonant DC-DC converter can be used in industry,and by adjusting the anode voltage and magnetic field,the microwave output has a good control effect,which has already meet the requirement of industrial applications.The power factor is higher than 0.95 and the efficiency is higher than 0.93.The method can be applied in industry.