Power Decoupling Enhancement of a Triple Active Bridge Converter With Feedforward Compensation Based on Model Predictive Control and Fuzzy Logic Controller in DC Microgrid Systems

Abstract

DC microgrids, which use various energy sources, require an energy storage system (ESS) to stabilize the grid systems. Multiport active bridge (MAB) bidirectional DC-DC converters offer several advantages over other converters, including higher power density, bidirectional functionality, reduced component counts, soft switching ability, and a reduced number of conversion stages. However, these converters are affected by the cross-coupling effect of the control variable, with the power dissipated at each port significantly impacting the system response to step changes. This causes unstable DC bus voltage, slow dynamic response, large overshoot, and limits its reliability. To address this issue, a power decoupling with feedforward compensation based on model predictive control (MPC) and fuzzy compensation control (FCC) was developed. The proposed control strategy can achieve good transient performance (lower settling time, overshoot/undershoot in the controlled variables), excellent decoupling control performance, and high control flexibility with good precision to comply with DC voltage regulations. This article investigates the PD-MPC-FCC and its implementation in a triple active bridge (TAB) converter with multi-winding high-frequency transformers. The proposed MPC-FFC integrates MPC with fuzzy compensation control. The MPC aims to obtain more precise current reference values and implement current feedforward control to stabilize the DC bus voltage, while the FCC adaptively compensates for steady-state voltage errors. A hardware-in-the-loop (HIL) experimental case study using Typhoon 602 validates the TAB converter’s performance with the proposed PD-MPC-FCC strategy. Additionally, a comparison with previous works confirms the effectiveness of the proposed method. The HIL experimental setup and comparative analysis results demonstrate that the proposed method is effective, providing faster dynamic characteristics and port power decoupling operation capability.

Keywords

• Multiport active bridge
• fuzzy compensation control
• model predictive control
• triple active bridge
• Typhoon 602
• dc microgrids