Fuzzy Logic System-Based Sliding-Mode Control for Three-Level NPC Converters
Hao Lin, Yunfei Yin, Xiaoning Shen, Abraham Marquez, Jianxing Liu, José I. Leon, Sergio Vázquez, Leopoldo G. Franquelo, Ligang Wu
Abstract
Nowadays, power converters have become the key to overcoming many challenges, so as to achieve more efficient transportation systems. Sliding-mode control (SMC) has become one of the preferred choices for power conversion applications because of its insensitivity to external disturbances. However, it is a challenge to suppress the chattering phenomenon. To solve this problem, in this article, a fuzzy logic system-based SMC strategy is proposed for three-phase three-level neutral-point-clamped power converters to improve the disturbance rejection ability, dc-link voltage regulation ability, and power tracking ability with good chattering suppression ability. The proposed controller is composed of three control loops. In the power tracking loop, a fuzzy super-twisting algorithm is proposed to force the active power and reactive power tracking their reference values. A fuzzy observer-based fuzzy SMC method is used in the dc-link voltage regulation loop to regulate the dc-link voltage to the reference value. Then, in the dc-link voltage balancing loop, a simple proportional–integral control strategy is utilized to balance the voltages of two dc-link capacitors. Finally, three groups of experiments are provided to validate the effectiveness and superiority of the proposed strategy.