Study on modal survey method of the harmonic resonance in micro-grid

Micro-grid technology has drawn more and more attention in recent years. It is very important that choosing an appropriate survey method of harmonic resonance to guarantee the stabilizing and compatible operation of the micro-grid. Because unique features of micro-grid technology, harmonic resonance in micro-grid reveals some new characteristics, such as complication of sources consisting in the resonance, width of resonance frequency spread in frequency spectrum, and parameter of elements participating the resonance changing rapidly. The traditional harmonic resonance analysis methods have some disadvantages, such as long time of analyzing progress and limited measure area. Traditional resonance analysis method cannot be applied to the harmonic resonance survey properly because of those shortcomings. In this paper a new resonance analysis method, modal analysis, is introduced into harmonic resonance survey in micro-grid. All of the harmonic resonance of the micro-grid could be found by the proposed method in very short time. Even with rapid changing of elements' parameters, the survey would be concluded with effective results by the proposed method in time. According to the survey results, proper measures can be taken place to improve the harmonic resonance in micro-grid. the method proposed in this paper can be approved to be rational and effective by the simulations results based on PSCAD. © 2009 Chin. Soc. for Elec. Eng.