A New Driving Method for a Magnetron Using A Soft Switching Active Clamp Fly-back Converter

Abstract

This paper presents a resonant active clamp flyback converter 1.6kW (4k V, 0.4 A) for driving a Magnetron for the sulfur plasma lamp. A magnetron is a vacuum lamp which works as a self-exciting microwave oscillator. In the presented paper, a high gain boost fly-back converter is used to achieve the High Voltage Power Supply (HVPS). An active clamp topology is utilized to decrease the main switch stress. Also a phase-shifted technique is proposed to reduce the maximum flux density of the transformer core. In addition, using the series-resonance circuit has provided the condition of soft switching. The power supply, depending on the required power, can control the peak and average power in minimum-loss condition. The instantaneous power of a microwave is 1600 W and its average power is 200-400 W, which is controlled according to on-state times of the converter. Other advantages of the proposed design are the simplicity of the power circuit, reduction in the number of switching elements, the leakage inductance of the power transformer, and switching losses. The design results have been simulated and verified through the PSIM software.