Reduction of Torque Ripple in an Axial Flux Generator Using Arc Shaped Trapezoidal Magnets in an Asymmetric Overhang Configuration

Abstract

In this paper, model of the axial-flux permanent magnet synchronous generator (AFPMSG) having arc-shaped trapezoidal permanent magnets (PM) is presented. The proposed model reduces the cogging torque and torque ripple, at the expense of lowering the average output torque. Optimization of the proposed model is performed by considering the asymmetric overhang configuration of the PMs, as to make the output torque of the proposed model competitive with the conventional model. The time stepped 3D finite element analysis (FEA) is performed for the comparative analysis. It is demonstrated that the torque ripple of the optimized model is highly reduced as well as average output torque is increased.

Design Optimization and Electromagnetic Performance Analysis of an Axial-Flux Permanent Magnet Brushless DC Motor with Unequal-Thickness Magnets

“…Thus, torque ripple and its reduction are currently of research interest to many researchers [29]. As is well known, the main sources of torque ripple are cogging torque [30], distorted stator current [31] and counter-EMF waveforms [32]. An effective method to reduce cogging torque is the optimization design of motor parameters based on the finite element method [33][34][35].…”

Analysis and Optimization of Axial Flux Permanent Magnet Machine for Cogging Torque Reduction

“…A symmetrical, sinusoidal-shaped radial flux permanent magnet machine (RFPM) was designed, which removes the harmonics of back-EMF more effectively and has been proposed as a method for obtaining reduced cogging torque [23]. In [24], a trapezoidal arc-shaped is introduced to reduce torque ripples and cogging torque. In arc-shaped PM, the effective length of the air-gap is increased, which is not identical across the one magnet; it is at its maximum at the pole edges and reaches its minimum at the center of the pole.…”