A Full-bridge LLC Resonator with Hybrid Control Mode for High-voltage Magnetron Power System

• Published in: 2024 Photonics & Electromagnetics Research Symposium (PIERS) pp. 1 - 8
• Main Authors: Lei, Gang, Xia, Zuxue, Xia, Wenhai, Li, Haoran, Cheng, Rui, Zhu, Yuyu
• Format: Conference Proceeding
• Language: English
• Published: IEEE 21.04.2024
• Subjects: Control systems; High-voltage techniques; Magnetic resonance; Pulse width modulation; RLC circuits; Simulation; Zero voltage switching
• ISSN: 2831-5804
• DOI: 10.1109/PIERS62282.2024.10617878

This article presents a high-voltage and high-efficiency magnetron power supply system. The power conversion part of the system includes three parts: bridge rectifier circuit, full-bridge LLC resonant circuit and double voltage circuit. This article optimizes the control strategy of the full-bridge LLC resonant circuit, and proposes a hybrid control mode: in heavy load conditions (high voltage), PSC (Phase Shifting Control) is used to control the voltage by changing the phase shift angle; in light load conditions (lower voltage), due to the difficulty of achieving ZVS (Zero Voltage Switching) with PSC, efficiency will decreases, and at this time, a combined control mode of PFM (Pulse Frequency Modulation) and PWM (Pulse Width Modulation) is switched, and in no-load conditions (all voltages), burst mode is used. The strategy can effectively extend the output voltage range and improve the output voltage efficiency at wide loads. The simulation results show that the maximum output voltage of the system is 4 kV and the maximum output power is 2 kW. The maximum efficiency is 92%, and the all load efficiency is more than 85%.