A modular 200kW-25kV DC medium frequency resonant converter for RF power amplifiers

Abstract

This paper focuses on the study and the implementation of a 25kV / 200kW / 20kHz rectifier intended to supply radio frequency power amplifiers with a DC voltage in a precision range of 1000ppm. The topology is based on three LCC resonant modules, and the high voltage part uses three 100kW / 20kHz power transformers connected to 72 diode full-bridge rectifiers connected in series. The design of such transformers as well as the management of the voltage balancing between the rectifiers and between the modules constitute new challenges addressed in this paper. The key design points of the transformers are described. Then, a simulation based analysis presents the issues in balancing powers and voltages between the modules. All the presented results are validated by experimental measurements on a full scale system.