Analysis and Control of Power System with Wind Generation

Abstract

The objective of this work is to study the impact of large scale wind integration in the dynamic performance of power system. The variable nature of wind generation has been driving power system operating conditions from a largely predictable one to highly variable and stochastic. Such changes will have huge impact in the dynamic performance of the system. The limitation in dynamic performance is one of the constraints for effective utilization of available transmission and generation resources. The thesis draws a qualitative behavior of inter-area mode damping with increased wind penetration. The factors such as changes in power flow and displacement of conventional generators, resulting from large scale integration of wind are considered. Another consequence of wind variability is the changes in controllability and observability in the context of power system damping control when operating conditions vary significantly. The modal controllability and observability decide the controller performance, large variation of which can result in inefficient control effort and poor stability margin. A controller design methodology using robust signal selection is presented for power systems with increased variability in operating conditions. The core of this method is based on stochastic error co-variance matrix of modal residue due to large variation in operating condition. The work further explores possibility of using wind farms for damping control using active and reactive power modulation. Interaction of damping controller with torsional mode of wind turbines is analyzed and a signal selection criteria is presented to reduce the interaction. Also, selection of active or reactive power modulation of wind farm for damping control is discussed. The outcome of this research offers deeper insight into the power system dynamic problem in the presence of large asynchronous generation such as wind.