This paper presented an overview of harmonic analysis and resonance in large wind powerplant. The harmonic related problem becomes a concern as the growing numbers of nonlinear load and the increased possibility of harmonic resonances occurrence. In WPP, several conditions may contribute to the resonance phenomenon that will amplify the effect of theharmonic frequency. General overview of international standards and grid codes and basic modeling of WPP for harmonic analysis is also presented. Furthermore, an overview of theharmonic analysis methods are reviewed with emphasize given on the harmonic resonanceanalysis. A simple three-bus system example is evaluated applying three resonance analysismethods.