This paper presents an analysis of the dynamic stability of weakly interconnected power systems considering the impacts of wind power technologies and FACTS devices. In addition, the paper presents the design and verification of FACTS-based supplementary controls for power oscillation damping (POD). Both the traditional frequency domain and adaptive genetic algorithm (GA) based designs of POD controllers are presented.
Due to their variable and intermittent nature, large changes in the power production from wind farms are usually detected. Therefore, the effectiveness of the traditional POD controller design is investigated considering a wide range of operating conditions. The integration of wind power in power systems is considered from two perspectives; replacement and addition. In the replacement situation, a specific amount of conventional power is replaced with the same amount of wind power. On the other hand, the addition situation refers to adding wind power to an existing conventional power generation system. The study system is composed of two weakly interconnected areas.
The objectives of wind power integration are to reduce the dependency between the two areas and to reduce the use of the conventional fuels. The integration process is subjected to the minimum damping constraint for keeping system dynamic stability. Two popular wind energy technologies are considered which are fixed speed SCIGs and the variable speed DFIGs. The results show that the wind power causes reduction in the damping of power system oscillations. Therefore, POD controllers are integrated with the available SVCs to improve the system dynamic stability. The POD designs are evaluated by the modal analysis and the time-domain simulation.
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