Design of High-efficiency Soft-switching Converters for High-power Microwave Generation

In this paper, the design of three types of power supplies for 30 kW and 60 kW industrial magnetron drives, a high-voltage power supply, a filament power supply and a magnet power supply, are studied. The high voltage power supply was designed based on the series resonant converter discontinuous conduction mode (DCM) to take advantage of a clean current source that could cover the nonlinear characteristics of a magnetron, such as a zener diode. The maximum output specification of a high-voltage power supply is 42.5 kW for a 30 kW industrial magnetron drive. This can also be used for a 60 kW magnetron with a parallel operation of two power supplies. The design considerations and feasibility tests of a resonant converter for an industrial magnetron are given. Additionally, the designs of two auxiliary power supplies (a filament power supply: 15 V, 120 A and a magnet power supply: 75 V, 5 A) are also provided. These were designed based on the series resonant converter continuous conduction mode (CCM) above resonance operation for higher efficiency. Finally, the developed power supplies were tested using both a 30 kW magnetron and a 60 kW magnetron. The results prove the design procedure and the reliability of the proposed scheme.