A fuzzy-logic-based multimodel field orientation in an indirect FOC of an induction motor

Classical indirect field-oriented control is highly sensitive to uncertaint ies in the rotor resistance of the induction motor. This sensitivity can be reduced by combining two different methods to compute the stator electrica l frequency, Fuzzy logic is used to combine both methods to obtain a compro mise which reduces the flux control sensitivity to electrical parameter err ors at each operating point. The design of the fuzzy logic block is based o n a theoretical sensitivity analysis taking magnetic saturation into accoun t, in simulations and in experiments. In this paper, the performance of the proposed control algorithm is theoretically and experimentally studied. Th e theoretical predictions are validated by experiments, by considering the stator current variations, to develop a given steady-state torque, induced by the imperfect flux control.