An Analytical Method for Analysis of Large-Disturbance Stability of Induction Generators

Abstract

This paper presents an analytical method for analysis of large-disturbance stability of squirrel-cage rotor induction generators. The proposed analytical method is based on the steady-state equivalent circuit of the induction generator and on the concepts of stable and unstable electrical-mechanical equilibrium points, which are calculated in the electrical and mechanical torque versus rotor speed space. This analytical approach sheds light on theoretical issues related to the stability of induction generators. Moreover, this method can be used as a guide to significantly reduce the simulation efforts necessary to assess the large-disturbance stability of induction generators. The method has been validated by comparing the results obtained by the analytical method with those determined by extensive dynamic simulation results through a sensitivity study. In the dynamic simulations, the induction generators are represented by a fourth-order algebraic-differential model. In addition, a simple approach is proposed for assessing the fault ride-through capability of induction generators.