Robust space-vector current control for induction motor drives

In this paper, analysis and implementation of two schemes for current control based on space vector modulation are proposed. A novel current control for vector control of the induction motor is presented in which the set of space voltage vectors are determined according to the stator current error in a stator reference frame. An off line switching table based on a software implemented comparator for minimizing this error has been implemented. Hence, optimal voltage vectors can be obtained from the inverter by using a switching table based on the angular coordinate. On the other hand, a modified predictive current controller based space vector modulation is proposed. In this technique, the space voltage vectors which are required to minimize the motor current error are calculated using a discrete motor model every sampling time. The proposed approach incorporates a modified conventional predictive current control with a new approach for reducing current ripples and decreasing the switching frequency. Simulation and experimental set-up results show the advantages and good performance of the two new modulation methods.