The paper presents current harmonic and interharmonic measurement of a Type-IV wind turbine. Characterizations and classifications have been performed with the representation of harmonics and interharmonics in a complex plane. The study of aggregations due to the summation of complex currents has been performed based on Monte-Carlo Simulation for harmonics and interharmonics. Aggregations occur less for low-order harmonics, more for high-order harmonics and most for interharmonics. Aggregations are shown to be largely independent of the produced power