An Applicable Method to Improve Transient and Dynamic Performance of Power System Equipped With DFIG-Based Wind Turbines

Abstract

The improvement of synchronous generators (SGs) stability is one of the most important issues in power systems. To this aim, doubly fed induction generator (DFIG) can be helpful. The main purpose of this paper is to improve both transient and dynamic performance of SG by using local DFIG-based wind turbines. Firstly, a transient controller (TC) is designed in controlling block of DFIG which changes its operating mode from generator to motor regime. Secondly, two damping controllers which are named electromagnetic torque band damping controller (ETBDC) and reactive power band damping controller (RPBDC) are suggested to improve dynamic stability of SG. Each damping controller includes three feedbacks namely, SG speed changes, SG electromagnetic torque and DFIG electromagnetic torque. Moreover, genetic algorithm (GA) is used to adjust these controlling parameters. The performance of TC is examined by comparison of system transient indexes such as critical clearing time (CCT), SG accelerating energy and DFIG inertia energy with and without using the proposed TC in a two-area test network. Similarly, system dynamic performance indexes such as overshoot, settling time, eigenvalue and damping torque of SG are compared with and without using two dynamic controllers. The obtained results show the effectiveness of proposed controllers.