Design and Testing of Passive Filters for Acoustic Noise Mitigation in Locally Manufactured Small Wind Turbines

Acoustic noise emissions in locally manufactured small wind turbines caused by current harmonics during low wind speeds, have been mitigated with the use of passive filters. In this paper various topologies of passive filters are investigated, while a set of appropriate design criteria are developed for such applications. Specifically, the L-RLC passive filter topology is optimized for minimum line current total harmonic distortion, minimum change in the terminal voltage of the axial flux permanent magnet generator, and for reduced power losses. The optimal filter design is manufactured locally and field tested for acoustic noise emissions, while also being compared to other passive filter topologies.