ACCURATE ROTOR FLUX ORIENTATION TECHNIQUE FOR INDIRECT ROTOR FLUX ORIENTED CONTROL OF INDUCTION MOTOR DRIVES

摘要

In this paper, a novel detuning index is first proposed for indicating the proper timing required to correct the rotor time constant of indirect rotor flux oriented controlled single-cage induction motor drives. This index can faithfully reflect the influence of rotor resistance changes as well as rotor flux changes. It also reduces greatly the number of rotor time constant estimations in practical applications. The theoretical basis of the index and the physical meaning are described in the paper in detail. Based on the proposed index, an on-line rotor time constant estimator is also proposed to make corrections. Only existing available quantities of the closed loop controller are used for calculating the estimated rotor time constant accurately. Both simulation and experimental results verify the effectiveness of the proposed rotor flux orientation technique. It is seen that the proposed rotor flux orientation technique is suitable for practical applications.