Research on Sliding Mode Control Strategy for DAB Based on Single-Phase Shift Modulation

Abstract

Introduction: With the rapid growth of the global economy, the issue of fuel resource shortages has attracted widespread attention. Countries are accelerating the transition from traditional energy sources to clean electricity. In this process, efficient energy transmission and storage technologies have become key challenges. The Dual Active Bridge (DAB) converter, due to its symmetric structure, soft-switching characteristics, and flexible control capabilities, has become a research hotspot for isolated DC-DC converters. However, systemic design strategies such as optimizing inductor current stress and extending the soft-switching range still require improvement. Additionally, traditional PI control has obvious deficiencies in dynamic response and robustness..

Objectives: Optimizing Performance of DAB Converters; Enhancing Dynamic Performance with New Control Strategy.

Methods: Control Strategy Improvement: Based on the full-bridge DAB single-phase phase-shift control, establish a dynamic model of the output voltage and propose a sliding mode control strategy incorporating an integral term.Simulation and Verification: Build a system model using MATLAB/Simulink and compare the dynamic response characteristics of sliding mode control with traditional PI control.Hardware Implementation: Complete the DAB system parameter design and key component selection, and develop hardware circuits to verify the theoretical feasibility.

Results: Compared to traditional PI control, the sliding mode control reduces the overshoot by 42% and the steady-state error by 68% during load transients.The proposed strategy extends the soft-switching range of the DAB to full-load conditions, and the peak inductor current decreases by 25%.Hardware experimental results show that the system efficiency reaches 96.2% at rated power, validating the effectiveness of the control strategy.

Conclusions: The sliding mode control strategy proposed in this paper significantly improves the dynamic performance and robustness of the Dual Active Bridge (DAB) converter, addressing the key drawbacks of traditional PI control. Through simulation and hardware experiments, this approach demonstrates superiority in efficiency optimization and steady-state accuracy, providing theoretical support and practical engineering reference for high-reliability power conversion systems. Future research could further explore multi-objective collaborative optimization strategies and improvements in wide-range input/output adaptability