Robust Optimal Control Design for a Soft-Switched AC–DC Bidirectional Converter

This paper presents an Multi-Input Multi-Output (MIMO) control strategy for a soft-switched AC-DC bidirectional power converter, optimally designed using an extended linear quadratic regulator (LQR) method. The proposed method is comprehensively compared with conventional approaches across three distinct scenarios: normal operation, harmonic mitigation, and grid imbalance conditions. Through detailed analysis and performance evaluation, our study demonstrates the superiority of the proposed control strategy in all three scenarios. Specifically, significant improvements are observed in harmonic mitigation and grid imbalance situations, where the proposed method exhibits exceptional effectiveness in reducing phase current total harmonic distortion (THD) and enhancing system robustness compared to conventional technique. These results emphasize the flexibility and effectiveness of the proposed control strategy in various operating conditions, indicating its capacity to improve the performance and reliability of AC-DC bidirectional converters in real-world applications.