Design Optimization and Performance Evaluation of Passive Filters for Acoustic Noise Mitigation in Locally Manufactured Small Wind Turbines

Acoustic noise emissions from locally manufactured small wind turbines, caused by current harmonics during low wind speeds, have been mitigated with the use of passive filters, thus increasing user community acceptance. In this paper various topologies of passive filters are investigated, while their optimal design is developed through a novel whole-system electro-mechanical approach. 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 and field tested for acoustic noise emissions and power performance, while also being compared to other passive filter topologies.