Modeling and Control of Three-Port DC/DC Converter Interface for Satellite Applications

TLDR

Multiport converters require multimode, multiloop designs, but cross‑coupled control loops and numerous operating modes make autonomous mode transition and closed‑loop control difficult. This paper develops a control strategy and power‑management scheme for an integrated three‑port converter that connects a solar input, a bidirectional battery, and an isolated output. The authors employ a competitive method for seamless mode transition, use state‑space averaging to model each mode, and introduce a decoupling network to enable independent controller design. Simulations and experiments confirm that the proposed control design achieves effective power management across all operational modes.

Abstract

This paper presents the control strategy and power management for an integrated three-port converter, which interfaces one solar input port, one bidirectional battery port, and an isolated output port. Multimode operations and multiloop designs are vital for such multiport converters. However, control design is difficult for a multiport converter to achieve multifunctional power management because of various cross-coupled control loops. Since there are various modes of operation, it is challenging to define different modes and to further implement autonomous mode transition based on the energy state of the three power ports. A competitive method is used to realize smooth and seamless mode transition. Multiport converter has plenty of interacting control loops due to integrated power trains. It is difficult to design close-loop controls without proper decoupling method. A detailed approach is provided utilizing state-space averaging method to obtain the converter model under different modes of operation, and then a decoupling network is introduced to allow separate controller designs. Simulation and experimental results verify the converter control design and power management during various operational modes.