Research on Power Decoupling and Optimal Control of Modular Multiactive Bridge Converter With Relay Port
Changyu Gao, Kai Li, Zhibo Zhang, Fan Yuan, Sheng Zhang, Xiaojie You, Chenchen Wang
Abstract
Modular multiactive bridge (MMAB) converter is a modular, scalable, and promising multiport converter that facilitates flexible interconnection among various power sources and loads. In the conventional MMAB configuration, all ports are coupled to a common high-frequency link through multiple high-frequency transformers, which inherently induces cross-coupling power flow between ports. This article proposed a modified MMAB converter structure incorporating an additional relay port to achieve hardware-level power decoupling. The proposed topology does not require a complex control strategy and allows each port to operate independently as an individual dual-active bridge converter without interaction. The principle of power flow decoupling is analyzed in detail using frequency-domain analysis. Furthermore, an optimal design and control method based on duty ratio control is proposed to expand the zero-voltage switching operating range of the converter. The proposed structure also effectively suppresses the high-frequency oscillation within the MMAB converter. Finally, simulation and experimental results were obtained from different test scenarios to verify the power decoupling performance and the proposed control strategy.