Transient stability analysis of dual excited synchronous generator with excitation control

Abstract

A Dual Excited Synchronous Generator (DESG) has two field windings. The stability enhancement of the power system can be achieved with felicitous control of these two field windings independently. Most of the work covered in the literature is on the stability analysis of DESG and the independent control of field windings. The independent control allows different amounts of current in field windings, which leads to unequal field losses and uneven rotor heating. The drawback is minimized in this work by keeping a predetermined angle between the excitation voltages. A simple excitation control similar to IEEE static exciter, regulates the d-axis and q-axis components of voltage, termed as Excitation type-1 (ET1), is presented in this paper. Also, the excitation system presented in the literature termed in this paper as Excitation type-2 (ET2) for comparison. The modified versions of both ET1 and ET2 are also presented to get overall improvement after a disturbance. The DESG connected to an infinite bus through a double-circuit transmission line is the system under study. Transient stability analysis of DESG with both types of exciters as well as Conventional Synchronous Generator for several disturbances in the system are presented, and also the results are compared.