A Novel Impedance Converter for Harmonic Damping in Loop Power Distribution Systems

An impedance converter composed of active and passive filters is proposed in this paper, which mimics the characteristics of an infinite transmission line, so as to eliminate the reflected wave and the damp background harmonic resonance in power distribution systems. The proposed impedance converter can be installed at any positions in the loop line, presenting a better damping performance and higher adaptability to the installation location compared with the traditional resistive active power filter whose damping performance is greatly dependent on its installation location. This paper gives a detailed description of the impedance converter, consisting of dual-Transformer realization and single-Transformer realization methods, among which dual-Transformer realization can be implemented by hybrid series active filters and parallel passive filter or series and parallel active filters, while single-Transformer realization only involves series and parallel active filters. Simulations and experiments have been performed to verify the theoretical analysis, and demonstrate the effectiveness of the proposed strategy.