Power Grid Current Harmonics Reduction and Voltage Balancing with 5-Level CHB Active Filter

Active filters, essential components of power grid infrastructure, play a crucial role in enhancing the quality of electrical energy. This paper proposes a control strategy design for an active filter consisting of three 5-level cascaded H-bridge converters. The proposed control strategy is based on a finite control set model predictive control, for which a comprehensive mathematical model of the system is developed. Power grid analysis, which is inevitable for the active filter proper function, is conducted using the PQ theory, which computes instantaneous active and reactive power. The performance of the proposed system is evaluated through a detailed set of simulations, and the sensitivity of model parameters is observed. The proposed system is compared with a 3-level topology to highlight its advantages.