Induction Machine Equivalent Circuit With a Tunable Core Loss Resistance Location and Its Offline Parameter Identification Method

An equivalent circuit incorporating the core loss is important for accurate analysis of induction machines(IMs). This paper proposes a novel IM equivalent circuit with an extra degree of freedom, which allows the location of the core loss resistance to be adjusted. By tuning the core loss resistance location, two mostly-used existing IM equivalent circuits can be regarded as special cases of the proposed model. To facilitate accurate parameter identification, a stator flux linkage controller is designed to maintain constant amplitude and frequency of the stator flux linkage during experiments. Based on this constraint, the stator current locus is derived and used to identify the location of the core loss resistance and other parameters offline. Experimental results demonstrate that the proposed equivalent circuit with identified parameters can accurately predict the states of the induction machine across a wide range of operating conditions.