A Virtual Impedance Comprehensive Control Strategy for the Controllably Inductive Power Filtering System

In this letter, a virtual impedance comprehensive control (VICC) strategy is proposed for the controllably inductive power filtering (CIPF) system with a new filtering mechanism. This control strategy aims to satisfy the zero-impedance design precondition of the inductive power filtering system, and can dampen the harmonic resonance at the grid side. By the proposed zero-impedance control, the quality factor of the passive power device can be adjustable, and the single-tuned filter can be multituned. First, the main circuit topology for implementing the VICC-based CIPF is presented. Then, on the basis of the multipurpose control, the VICC strategy is designed. Furthermore, by means of the established equivalent circuit model and the corresponding mathematical model, the principles of the harmonic damping and the zero-impedance realization are revealed. Finally, the experimental results verify that the proposed control strategy can weaken the harmonic amplification effectively, and improve the filtering performance significantly.