Voltage Harmonic Suppression by Means of Grid-Connected Converters Using only Local Measurements

Abstract

A single-phase grid-connected converter is considered in this paper in the presence of harmonic problems introduced non-linear loads. In order to compensate the harmonics caused by the loads, a local voltage support scheme is proposed. This is an added feature because its implementation is in parallel with a conventional current control method. Distinctively, the measurements of the grid or load current are not needed since the scheme is based on only local measurements. On top of a fundamental part for desired power injection, the converter output current comprises a harmonic part for compensation. Thus, the grid current harmonic distortion is minimized and the enhancement of the local voltage quality is achieved. A comprehensive model analysis indicates that the proposed strategy can help to attenuate harmonics of the local voltage without compromising on the quality of the fundamental current injection. Experimental results validate the effectiveness of the proposed control scheme. Moreover, the impact of grid frequency estimation error on the control strategy’s performance is quantified theoretically and experimentally.

Design and Implementation of Novel Multi-Converter-Based Unified Power Quality Conditioner for Low-Voltage High-Current Distribution System

“…With the development of science and technology, the electronic loads have increased largely [2]. A great amount of harmonic loads has been employed in the manufacturing industry, entertainment centers and financial enterprises, which can inject plenty of harmonic currents into the grid [3][4][5]. Furthermore, large numbers of single-phase loads are connected to the distribution system [6].…”