Discrete-time modelling of induction motors with consideration of magnetic saturation
Résumé
Time-discretization of nonlinear continuous systems is intensively resorted to cope with digital implementation. In system control, time-discretization may concern either nonlinear models or nonlinear regulators. This paper focuses on the problem of discrete-time modelling of induction motors. The aim is to get models that can be based upon to get digital simulators, observers and regulators for the studied machines. The problem of interest is dealt with by combining different discretization techniques, namely Euler approximation, Carleman linearization and Taylor-Lie expansion. These are applied to an experimentally validated continuous-time model that account for the nonlinear feature of the motor magnetic characteristic. The sampling frequency is set to 1 KHz, which is the cutting frequency of the underlying inverter. The discrete time models thus obtained are compared through simulations.