PREDICTION OF COGGING TORQUE USING THE FLUX-MMF DIAGRAM TECHNIQUE

An improved approach to predicting cogging torque in permanent magnet motors using the flux-MMF diagram technique is presented and validated , A brief review of cogging torque calculation and minimization techni ques is included, It is shown that the flux-MMF diagram can be constru cted for any one pole of a permanent magnet machine using the demagnet ization characteristic of the permanent magnet; then by applying the p rinciple of virtual work, cogging torque can be predicted, It is also shown that the flux-MMF diagram technique is a truly universal techniq ue of cogging torque prediction and gives greater insight into many of the methods used for cogging torque minimization.