A Comparison of Three State-Space Models of an Induction Machine Derived from the Same Set of Conductor Distribution Harmonics

The paper discusses three state-space models of a low-power off-the-shelf induction machine. Each of them considers the same set of conductor distribution harmonics consisting of orders 1 and 17. This specific configuration is interesting as it generates a principal slot harmonic (PSH) in the stator currents as well as torque oscillations. The three models are of order 6 and differ from each other with respect to the state variables involved and the reference frame in which the model equations are expressed.The models are evaluated on the basis of their complexity, numerical accuracy and potential for use in practical applications. In this regard, a model variant with stator currents and rotor fluxes as state variables appears particularly promising for use in drive control, for instance to extend existing field oriented or predictive control schemes.