Transient trajectory control of permanent magnet synchronous machines with nonlinear magnetics

High performance interior permanent magnet synchronous machines show nonlinear magnetics due to saturation and cross-coupling. Nonlinear differential equations describe these phenomena and make feedback control challenging. This paper presents a predictive control method to precisely control the dynamics of these machines. Four real-time capable strategies to online identify transient trajectories are proposed: Two straight line trajectories, a strategy that yields a fast torque response and a strategy that reaches the reference values in a short amount of time. A predictive control method to force the machine to precisely follow the selected trajectory is developed and analyzed using simulations and test bench measurements. Thus, advantages and disadvantages of specific trajectories are identified. This allows the selection of a proper strategy depending on the drive requirements.