Influence of the Stator Current Approximation Form on the Discrete Sliding Mode Torque Control for Induction Motor Drive

This papers deals with discrete-time sliding mode control for induction motor. Main objective of the control structure is to control stator current vector components in stationary frame. However, this can be easily extended to allow control of the components expressed in synchronous frame and both electromagnetic torque and rotor flux amplitude. PI speed controller connected with the torque/flux control is verified as well. The main aspect of this paper is to verify the influence of the stator current approximation form on the overall control performance. Four most popular numerical methods are applied and analysed. Moreover, the sampling frequency is taken into consideration as well. The paper is illustrated with simulation results for 1.5 kW induction motor drive.