Research on technology to reduce high-frequency ripple of electron gun power supply

During the process of electron gun evaporation of metal, the electron beam spot determines the electron gun power density. The electron gun acceleration voltage ripple has an impact on the beam spot. The main circuit is multi-phase interleaved and digitally controlled with precise feedback to achieve low-temperature voltage wave output. Theoretical calculation and simulation model analysis methods were used to obtain the effectiveness and rationality of the three-phase interleaved structure of the main circuit, improve the effective operating frequency, and carry out 30 kW and 30 kV power supply main circuit parameter design based on the main circuit working process. The theoretical parameters of the resonant inductor, resonant capacitor, transformer rectifier diode and filter capacitor to achieve <0.5% ripple are given. The open-loop transfer function is obtained using the frequency sweep method. For different loads, closed-loop simulation is performed to summarize the relationship between the load and the control parameters. Design multi-threaded digital control phase shift control software program and algorithm and establish a test platform to verify single-phase 30 kHz (effective operating frequency 90 kHz), output voltage 30 kV, and output power of 10 kW, 20 kW and 30 kW respectively, 0.48% (Vpp=145 V) ripple, achieving a full-range output ripple of less than 0.5%.