A Stacked Resonant High Voltage DC Modulator for Industrial Magnetron

This paper presents a design of a 8.8kV DC modulator for anode power supply of a 10kW magnetron. The DC modulator requires to follow a specific output voltage profile from 6.8kV to 8.8kV, while the magnetron switches from the preheating state to the steady operation of full power. The design is based on series resonant converter for its high power density, feature of soft switching and inherent safety. Initially, a single resonant converter based design is detailed, and then it is argued that stacking of multiple modules is advantageous for ease in testing, maintenance and components selection. So, a design based on three stacked converters is presented, and simulated for its working, and characterization of the transient response and to help select the components of suitable ratings and to help design a control system. Hence, this work has laid a strong foundation for fabrication of the required DC modulator.