Holistic Design of Small-scale Stand-alone Wind Energy Conversion Systems Using Locally Manufactured Small Wind Turbines

Abstract

A holistic and multi-disciplinary design approach is developed for small-scale stand-alone wind energy conversion systems (WECS) using locally manufactured small wind turbines (LMSWTs), with the aim of reducing capital and maintenance costs while increasing the annual energy production and energy utilization of such systems. Various subsystems are analysed and modelled, using both sequential and integrated design approaches, such as the rotor, including the airfoil and blade geometries, the axial flux permanent magnet generator including economic, thermal and structural aspects of the stator and rotor geometry, the furling system and the electrical system, including the power transmission cables and the battery bank. The holistic design approach is then applied to a 2.4m rotor diameter LMSWT and the complete WECS is dimensioned. Finally, the designed low cost system is compared to a high cost system using a maximum power point converter, with satisfactory results especially for low wind speeds around the mean wind speed of the site. It is thus concluded that a holistic and multi-disciplinary design approach to small-scale stand-alone WECS using LMSWTs, can lower the cost of energy for rural electrification applications by reducing capital costs, while sustaining the system’s efficiency and annual energy production in low wind speed regions.