Uniqueness for constant control of torque-transfer function in induction motor

The uniqueness of the constant control for the torque-transfer function (CCTTF) is discussed. The CCTTF has been developed for high-performance induction motor drives with a current controlled source. Two regions are discussed: the constant field region and the field weakening region. In the constant field region, two control schemes, vector control (VC) and a field acceleration method, have already been presented. However, in order to realize CCTTF, only VC is possible. In the field weakening region, the generation of the transient torque which disturbs CCTTF is inevitable. It is proved that there exists a unique way of minimizing the transient component, and such a control is proposed.<>