Design of a modular resonant converter for 25kV-8A DC power supply of RF cavities

Abstract

This paper describes the design of an Lee resonant tank that is to be used in a 300k W modular power converter for an application in particle accelerators. The aim of the power supply is to provide a so-called RF cavity with 25k V De and a current up to SA. Modular approach is chosen for redundancy and availability. Each module is composed of a resonant tank with a step-up Medium Frequency Tr ansformer with its secondary windings put is series. Full gain is ensured in the full operation frequency range considering component value inaccuracies and ageing of capacitors. The paper focusses on the design of the resonant tank and its implementation in a lOOkW power module prototy pe.

Modelling a Multilevel LCC Resonant AC-DC Converter for Wide Variations in the Input and the Load

“…Of course, a reduction in the transformer ratio affects the value of parasitics when observed from the primary. In fact, L S is multiplied for (133/70) 2 and C P is divided by the same quantity. Therefore, it is possible to modify just the primary of the transformer and to obtain the new desired parasitics on it-Additionally, this new primary will occupy more or less the same volume in the core window, since the number of turns is almost doubled but, as later demonstrated, the current is going to be halved.…”

“…A significant number of industrial applications require a power supply capable to deliver a DC voltage of tens of kV while transferring a power of tens of kW. Such applications include X-ray generators, electron beam welding machines, or electrostatic precipitators to name a few [1][2][3][4][5]. In all cases, the primary power supply is a three-phase line.…”

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

“…Modularity can be achieved by using several multisecondary windings medium frequency transformers with a high number of output rectifiers. This modular approach allows degraded operation with a faulty module [1] since a faulty module can be shunted without jeopardizing the operation of the converter. Moreover, using a soft-switched LCC resonant converter allows achieving a relatively high switching frequency with moderate losses [2], leading to reduced step-up transformers volume.…”