A generalised operational equivalent circuit of induction machines for transient/dynamic studies under different operating conditions

The paper derives a generalised operational equivalent circuit for induction machines starting from fundamental principles in any arbitrary rotating reference frame. Directly measurable parameters are used in this equivalent circuit. From this generalised model, the equations for any reference frame are derivable as particular cases. The model presented is versatile as it can be used for any operating condition and any asymmetrical connection or switching and for both three-phase and two-phase wound machines. The equivalent circuit provides space phase vectors and the relevant expressions can be used to develop software for online control of motors through field orientation. Different possible modes are considered in this paper to derive relevant equations from the general model to illustrate its potential