A New Stability Index for Induction Motors Three-Phase Fault Recovery in Industrial Networks Based on Post-Fault Slip Estimation

In the present paper, an attempt has been made to introduce a new Stability Index (SI) for induction motors (IMs) three-phase fault recovery in industrial networks. The proposed SI is based on the steady-state model of induction machine as well as the usage of concepts related to stable and unstable equilibrium points. This index is evaluated by estimating the post-fault slip and is a function of the maximum slip and slips related to the induction motor operating point in pre-fault and post-fault torque-slip characteristics. Moreover, this index quantifies the amount of stability in addition to the stability state determination. The method is validated through comparison between the analytical and dynamic simulation results. Sensitivity analysis has also been used to describe the proposed index completely. This paper also presents a novel objective function by which the fault recovery process can be done optimally. The proposed method presented in this paper has also been applied to two industrial networks, one of which is the modified IEEE 9-bus system.