Analysis of Resonant Component Tolerances Influence on the Current Imbalance of a Multiphase Interleaved Resonant Converter

The paper presents an unregulated three-phase isolated series resonant converter. The proposed converter is used for short-term auxiliary power supply to the electric motor drive inverter from a battery energy storage system. The series resonant converter features simple implementation and high power density due to the high efficiency achieved by soft-switching. Due to the relatively large converter current, a multiphase, i.e., three-phase interleaved, topology was used. The disadvantage of this topology is the unequal sharing of the load current among the phases. Current imbalance between the phases can lead to unacceptable component current stress and cause a reduction in system efficiency and reliability. In this work, a simulation model has been developed to study the effect of resonant component tolerances on current imbalance between the three phases of the proposed converter. Measurements on the physical model confirmed the results of the simulation experiment.