A direct-coupled, wind-driven permanent magnet generator

With the development of high-energy permanent-magnet materials, it is possible to make permanent magnet generators more reliable and compact. Investigation shows a growing demand for wind generators with larger output power used at hybrid energy systems in remote areas. This paper presents the design of a 20 kW permanent magnet generator using neodymium-iron-boron magnets for direct-coupled, low-speed wind turbine applications. Due to outer-rotor, multi-pole structure can be easily implemented. Lumped parameters of the magnetic equivalent circuit for the generator were used in electromagnetic calculation aided by a computer program. It is aimed to obtain accurate design data and prediction of machine performance by using this approach. Tests have been conducted to investigate the performance of the generator. According to the results of calculation and experiment, there is a good agreement between computations and measurements.