review in transverse flux permanent magnet generator design

recently, transverse flux permanent magnet generators (tfpmgs) have been proposed as a possible generator in direct drive variable speed wind turbines due to their unique merits. generally, the quality of output power in these systems is lower than multi stage fixed speed systems, because of removing the gears, so it’s important to design these kinds of generators with low ripple and lowest harmful harmonics and cogging torque that is one of the most important terms in increasing the quality of output power of generator. the objective of this paper is introducing a simple design method and optimization of high power tfpmg applied in vertical axis direct drive wind turbine system by lowest possible amplitude of cogging torque and highest possible power factor, efficiency and power density.  in order to extract the output values of generator and sensitivity analysis for design and optimization, 3d-finite element model, has been used. this method has high accuracy and gives us a better insight of generator performance and presents back emf, cogging torque, flux density and fft of this tfpmg. this study can help designers in design approach of such motors.