Using the Short Circuit Analysis in the Study of the Induction Machine Disconnection from the Grid

Abstract

This paper presents a method to study the disconnecting from the power grid transient of an induction machine. It is assumed that a three-phase load is connected to the same grid. Considering the parameters of the load impedance included in the stator equivalent circuit, in case of disconnection from the grid the problem is reduced to studying the transformed induction machine under short circuit. In this paper, the transient stator currents of the induction machine compared to those of transformed machine have been studied. In order to simplify the problem, the rotor speed is assumed to be constant at synchronous speed all over the time interval of interest. The analysis has been performed by simulation. The obtained results were compared to the theoretical ones. Finally the natural components and their characteristic parameters have been presented. Conclusions regarding the nature and the duration of the transient operation have been drawn.