Development and performance evaluation of direct drive axial flux permanent magnet generator for small-scale wind turbines

Purpose The increasing energy demands, high cost of nonrenewable energy resources such as fossil fuels, and global warming caused by rising environmental pollution emphasize the importance of renewable energy sources. Wind energy has gained significant attention recently due to its proven technology and no greenhouse gas emissions or waste products. Design/methodology/approach This paper presents the design and analysis of coreless Axial Flux Permanent Magnet (AFPM) generators for low cast wind turbine applications. These types of wind turbines are particularly well-suited for use in urban industrialization and rural electrification. The presented AFPM machine topology consists of two rotor stacks, permanent magnets, stator support and bearings which eliminate the use of gearbox for wind turbine applications. In wind turbines, the cost and maintenance are increased due to the usage of gearbox that has eliminated in the analyzed AFPM machine topology. Initially, the performance of coreless AFPM generators is evaluated through finite element analysis. Subsequently, the prototype is fabricated and tested which shows compactness and rigidity while having very low weight. Findings The fabricated prototype demonstrated high compactness and structural rigidity while maintaining a very low weight. The reduction in weight contributed to minimizing mechanical losses and lowering cogging torque. As a consequence, mechanical losses and cogging torque are minimized, which leads to an increased efficiency of 92%. Originality/value This work uniquely emphasizes the integration of glass fiber reinforced plastics (GFRPs) material in the construction of the AFPM generator. The use of GFRP significantly reduces the overall weight of the machine, leading to the increased torque density and efficiency. This coreless topology achieves high-performance, lightweight direct drive wind turbine generators suitable for cost sensitive applications.