Electronic Thesis and Dissertation Repository


Master of Engineering Science


Electrical and Computer Engineering


Dr. Tarlochan S Sidhu

2nd Supervisor

Dr.Amirnaser Yazdani

Joint Supervisor


Wind is the most reliable, clean and fast-developing renewable energy source. The DFIG-based variable speed wind turbine system is now the most popular in wind power industry. With power being so in-demanding, a large wind farm needs to be developed to produce more power from a stable system. But before such a large wind farm is installed, better understanding is needed of the system’s intrinsic dynamic behavior, range of stability region and parametric effects on system stability. Hence, a small wind farm with two identical DFIG-based wind turbines connected to a grid network has been considered for this study.

A detailed non-linear mathematical model of grid-connected single DFIG-based wind turbine system as well as a grid-connected multi DFIG-based wind turbine system in a dq-frame has been developed. Linearization of these non-linear mathematical models for both the systems has been performed from the set of developed non-linear equations. These two linearized dynamic models provide an analytical platform for determining the robustness and stability of the two systems. The linearized models are then verified with the simulation results of non-linear systems designed in a PSCAD/EMTDC environment. This step is needed to check the performance accuracy of the linearized models. The small-signal stability, the system’s parametric effects on stability and the modal analysis of two developed linearized models have been studied. Participation factor analysis has been employed to determine system parametric effects on each eigenmode. The intrinsic dynamic behavior of a single wind turbine connected to a grid and multi wind turbines connected to a grid (a small wind farm) are observed to be identical in nature at the same operating conditions and system parameters.