A Transient Model Of Wicsc And Iscad Machines Based On Permeance Networks

Today, multiphase electric machinery is considered in automotive traction applications. Some multiphase machine topologies also enable the possibility to change the pole and/or phase number during operation, an option which can be of benefit thanks to the large speed range that an electric machine for traction applications typically operates with. In this paper, an analytical model of the current dynamics for the wound independently-controlled stator coils (WICSC) and the intelligent stator cage drive (ISCAD) machines is presented. The model, based on setting up a permeance network in the stator and rotor and a rotor-angle dependent connection between the two networks, allows for predicting current transients during pole and phase changes. Thus, it is suitable for the design of control methods exploiting both the multiphase nature of the machine as well as performing pole-number changes during operation. The presented model is validated by comparing results from a corresponding finite-element based model of a WICSC machine during a pole change.