AmirHossein Taheri Jam - Electrical Engineering Department, Shahid Beheshti University, Tehran, Iran
Reza Mohammadi chabanloo - Electrical Engineering Department, Shahid Beheshti University, Tehran, Iran
Ehsan Bagherzadeh - Electrical Engineering Department, Shahid Beheshti University, Tehran, Iran
Hossein Askarian Abyaneh - Department of Electrical Engineering, Amirkabir University of Technology, Tehran, Iran
Mojtaba Nasiri - Department of Electrical Engineering, Amirkabir University of Technology, Tehran, Iran.

Nowadays, with increasing penetration of Induction Generators (IG) in the electricity grid, it is of great importance that IG be connected to the grid in the fault conditions. In this paper, a terminal voltage based method for transient stability study of IG is proposed. For this purpose, an improved analytical method is used to determine Critical Clearing Time (CCT) of IG in the state of grid fault, including near and non-near faults. For the faults occurring far from the terminal of generator, electromagnetic torque is not equal to zero during fault. Hence, equivalent circuit model of IG and network is used to calculate the CCT. A new formulation based on terminal voltage of IG is presented to consider the stability constraint on Over Current Relay (OCR) coordination, to prevent disconnecting of IG in grid fault condition. Simulations are carried out on two samples network, and the results demonstrate the efficiency of proposed method.

Induction Generator, Transient Stability, Grid Fault, OCR coordination, Genetic algorithm