Effect of saturation on equivalent circuit analysis of induction motor in practical scenario

Equivalent circuit approach is the most generally used method for the analysis of induction motor (IM). Equivalent circuit method is based on the assumption that IM operates in the linear region of magnetizing curve. However, in practice many a times motor needs to operate in the non-linear magnetic region where the magnetic saturation of the core cannot be avoided. This causes deviation in the results obtained from equivalent circuit in comparison to practical values. In this paper, effect of saturation on the equivalent circuit has been analyzed. Error calculation between the practical and equivalent circuit has been presented for a set of 12 squirrel cage rotor IMs. It has been observed that as the saturation increases error between the two values also increases. The saturation in the machines is analyzed with finite element method (FEM) calculation.