A multiphase series-resonant converter with a new topology and a reduced number of thyristors

Multiphase series resonant (SR) power converters provide a flexible way to transform power between a utility grid and a multiphase load or source. The current implementations all suffer from a high component count, which makes the use of these power converters unattractive from an economical point of view. A new topology for multiphase SR power converters has been proposed in the literature in a simulation context. This topology uses half the number of power semiconductors compared to the existing multiphase SR power converters. The present paper addresses the implementation of the new topology in a prototype power converter. The old and new topologies are presented. The operation of the new topology is explained. In the new topology the resonant circuit is grounded at one side, which compared to the old topology imposes a restriction on the operation. The paper shows both simulation data and measured waveforms. It is explained that the economical gain due to the reduction in component count is offset by a lower power rating. The paper finishes with conclusions and acknowledgment