Modeling of practical nonidealities in a permanent magnet synchronous motor drive

The modeling of a permanent magnet synchronous motor drive with different practical nonidealities is presented in this paper. Many papers have addressed saturation effects but issues such as friction, cogging, delays and truncation effects in the digital control system seem to have been largely ignored. In applications such as electric power steering where the performance requirements are stringent, all of these issues need evaluation so as to accurately predict performance and provide understanding of the system interactions. The practical issues listed above were incorporated into a simple model to make it closer to the practical set-up. The model was exercised on different loads, and both the dynamic and steady state behaviors of the drive system had been observed from the motor torque, speed and current plots at different operating conditions. This development contributes to the motor performance predictions after the motor design stage and serves as a tool to help analyze system interactions.