Multimode Control of HF Link Universal Minimal Converters - Part I: Principles of Operation

This two-part paper presents a novel multimode control scheme for a family of single-stage high-frequency-link bidirectional converters with DC or AC ports. These configurations represent a family of universal-minimal-converters (UMC), which can all be reduced to a generic unit cell over each switching cycle using the proposed multimode control scheme. This universal and simpler control integrates major parasitic while achieving lower device stresses than traditional schemes. A mode selection strategy is also utilized to optimize the performance of considered UMC-unit cell over each switching cycle. Further, each cycle starts and ends with zero current to reduce energy storage and manage transformer saturation. Detailed derivation of the UMC-unit cell operating characteristics using the proposed control scheme is presented, along with simulation results to verify the operation. A hardware prototype of UMC is built and tested to validate the multi-mode operation of the proposed UMC-unit cell. Part II of this paper series discusses the DC to multiphase AC operation realization.