Fractional-Order Integral Sliding-Mode Flux Observer for Sensorless Vector-Controlled Induction Motors

The control performance of sensorless vector-controlled induction motors mainly relies on the accurate flux estimation. However, due to the variations of electrical parameters, the inaccuracy of estimated fluxes will cause the performance degradation of speed control. In this paper, a fractional-order integral sliding-mode flux observer is provided to estimate the d- and q-axis fluxes in the stationary reference frame. In addition to simulations, a DSP/FPGA based experimental platform is setup to evaluate the feasibility of the proposed scheme. Simulations and experimental results illustrate that the performance of flux and speed tracking can be performed as desire by utilizing the fractional-order integral sliding-mode flux observer in a wide speed range.