This paper presents a perturb-and-observe-based optimization approach for efficiency maximization and total harmonic distortion (THD) minimization in a 3 × 3 matrix converter under varying D-axis current references (Idref). In matrix converters, the phase shift and modulation index significantly influence power transfer characteristics, harmonic performance, and conversion efficiency. However, fixed-parameter control strategies often fail to maintain optimal performance over varying operating conditions. To address this limitation, two independent perturb-and-observe-based optimization strategies are developed for adaptive phase-shift tuning in efficiency and THD optimization. In both approaches, the modulation index is regulated using a PI controller to maintain stable current regulation and proper voltage utilization. The proposed methods rely only on AC-side measurements, avoiding explicit analytical optimization and enabling simplified implementation within existing converter control frameworks. The effectiveness of the proposed strategies is validated through MATLAB/PLECS simulations of a 3 × 3 matrix converter under multiple operating conditions (Idref=10, 20, and 30 A). The semiconductor switching and conduction losses are included using the Infineon FS13MR12W2M1H device loss model available in the PLECS semiconductor library. The results demonstrate that the adaptive phase-shift adjustment successfully converges toward operating points with improved efficiency and reduced THD compared with conventional fixed-step methods. Furthermore, the proposed perturb-and-observe-based strategy demonstrates good adaptability across varying operating conditions while maintaining relatively low computational complexity, making it suitable for practical real-time implementation in matrix converter applications.
Krovi et al. (Sun,) studied this question.