We present a general procedure for the design of permanent magnet synchronous. This method based on analytical model is checked by a Finite Element Analysis. After, an appropriate model of PMSM is developed. The proposed model enables to take account of all non-ideal characteristics of this machine such as cogging torque, ripple torque. Knowing that torque smoothness is an essential requirement in a wide range of high performance motion control applications, this model can be used to study controller based techniques for minimising pulsating torque. Usually the design of machine is based of steady state, for news applications, it is important to consider dynamics aspects.