A New SVM Strategy to Suppress Total Harmonic Distortion and Current Stress in HFLMCs

High-frequency link matrix converters (HFLMCs) can transfer dc to ac with only one power conversion stage and without intermediate energy storage components. However, the space vector modulation (SVM) strategies and control methods in conventional HFLMCs produce excessive harmonics in the three-phase output currents and high current stress in the primary side of the isolated high-frequency transformers (HFTs). This article proposes a new optimal vector distribution SVM strategy, which maintains low switching action and reduces output current harmonic. The HFLMC's transmission power and the HFT's current stress with the proposed SVM strategy are analyzed, and a coordinated control method coupled with the modulation index and phase shift angle is determined. The proposed SVM strategy and the coordinated control can realize smaller total harmonic distortion (THD) of three-phase currents and lower HFT's current stress than the conventional SVM strategy. The simulation and experiment results confirm a low THD of 3.71% in the output current and a remarkable decrease of the current stress (2.5 to 3 A) in the HFT.