Impact Studies of Connecting Tuned Harmonic Filters onto a Brazilian Wind Farm

Abstract

Wind farms are power generation complexes with nonlinear characteristics. It is well-known that such facilities are potential sources of harmonic current injection upon the network. In this sense, in cases where limits established by the regulatory agencies are exceeded, filtering strategies must be provided. Under these circumstances, passive filters are a widely employed solution for bringing harmonic distortion levels to within standard limits. However, it is recognized that the connection of passive filters can influence the characteristics of the system, causing resonances and even the intensification of harmonic distortions at the connection point between the wind farm and the external network. Therefore, this paper aims at evaluating the impacts of tuned harmonic filters on grid resonance characteristics and harmonic distortion levels from a wind farm. In this way, based on measurements of currents from an existing Brazilian wind power plant, computational studies are performed in accordance with the guidelines given by Brazilian regulations.