Online diagnostics is prefered specifically in critical induction machines for timely analysis of there health and to predict any incipient failures. For early fault detection, the negative sequence current component can offer a fast and reliable monitoring technique. However, the negative sequence component method contains inherent non-idealities (such as inherent machine asymmetries) and is sensitive to external effects (such as load change and supply voltage imbalnces). This paper address these limitations while considering real system disturbances and non-linearities using a dynamic motor model effectiveness of the nagative sequence component analysis as well as the behavior of the model under load change and voltage unbalance was discussed. The nagative sequence components due to stator faults and the interaction with voltage and load variation were also presented in the paper.