Three phase induction motor torque tracking algorithm based on the rotor time constant identification

Abstract

The indirect vector control system can realize the on-line identification of the rotor time constant based on electromagnetic torque. However, still effective range of the torque model is suitable only for heavy load conditions. In this paper, an improved torque tracking model is constructed by modifying the conventional torque model with rotor time constant identification. Through the establishment of the small signal model of the identification system, the stability of the torque model is deeply analyzed, and it is concluded that the torque model has two balance points, namely the expected balance point and the error balance point; the error balance point limits the scope of the torque model root cause. The simulation show that the problem of unbalance point can be avoided with the aid of the proposed algorithm. In addition, the design ideas of proportional-integral adaptive law parameters are given from the two perspectives of system stable operation and optimal convergence process.