Vector control of cascaded induction motors

This paper presents experimental results of a stator flux-oriented control scheme. This scheme has not previously been applied to the cascaded doubly-fed induction machine (CDFM). In particular, the influence of the closed rotor circuit loop on the control structure has been investigated. It is found that the presence of the closed rotor circuit loop introduces a cross coupling between the d-axis and the q-axis in the stator flux reference frame. However, the cross coupling has only a minor effect on the overall control concept. It is therefore possible to achieve decoupled control of torque and flux in the CDFM. In comparison to a previous field oriented control method for the CDFM, the scheme in this paper is independent on the CDFM machine combination.