Bidirectional Single-Input Multiple-Output Power Converters: Model and Performance Analysis

This paper introduces a small-signal transformation model based on the cantilever approximation for transformers commonly used in LLC converters. The proposed transformation is evaluated towards extending resonant converters in multiport applications. The transformation is compared in a traditional LLC multi-active bridge against a cascade multilevel inverter configuration on the secondary side. The objective is to analyze the differences and similarities in their implementation and assess their impact on system efficiency based on topology, with a focus on comprehensively describing losses in resonant multioutput converters. Two low-power prototypes were developed to validate the proposed model and approximation. The case study examines the efficiency and cross-regulation trade-offs between the configurations. Simulation and experimental results verify the accuracy of the analytical approach, offering valuable insights for designing and implementing high-frequency transformers in multiport applications.