Vector control methods for induction machines: an overview <s> A. Rotor Flux Slip Control <s> The sensitivity of the parameters of a rotor-flux-oriented system using rotor flux estimation is discussed, and a stator-flux-oriented scheme is developed. Since the estimation of the stator flux is independent of the leakage, the steady-state performance of the stator-flux-oriented system is insensitive to the leakage inductance. A decoupler is designed to minimize the coupling in the stator-flux reference frame, improving the dynamic performance of the system. Digital simulation is carried out to show that the performance of the stator-flux-oriented system is superior to that of a detuned rotor-flux-oriented system. > <s> BIB001 </s> Vector control methods for induction machines: an overview <s> A. Rotor Flux Slip Control <s> 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. > <s> BIB002 </s> Vector control methods for induction machines: an overview <s> A. Rotor Flux Slip Control <s> The field acceleration method (FAM) and the indirect field-oriented control (FOC) for current-fed induction machines are theoretically compared, and their block diagrams are analyzed. It is shown that the indirect FOC and the T-1 type FAM are exactly the same. Moreover, the equivalence between the spiral vector used in FAM and the space vector used in FOC is demonstrated. The FOC theory explains the direct FOC, where an estimation of a direct measurement of the rotor flux is done. This direct scheme allows independent control loops for flux and torque, and thus can be considered more general than the FAM or the indirect FOC. > <s> BIB003
As already mentioned, in this case and (4) can be written exactly as BIB002 . Therefore the control scheme is valid under transient and steady state conditions. Moreover, from (1), it can be seen that there exists a direct relationship between (the torque current component) and the slip, as shown in (7) (7) Then, substituting (7) in (5), (8) below can be obtained. This is the equivalent quadrature form of (5) BIB001 This means that the rotor-flux based slip control and the rotor-flux based quadrature control are equivalent. For example, the FAM control applied to the T-I model  can be mentioned. Moreover, reference BIB003 also shows the equivalence of this control scheme and the indirect FOC.