Incorporating correlation in the adequacy evaluation of wind integrated power systems

Abstract

Environmental concerns caused by burning fossil fuel and the safety concerns associated with nuclear power plants have led to increased interest and investment in wind power. Wind penetration in power systems is rapidly increasing world-wide and creating significant impacts on the overall system performance. The impact of wind generation on the overall system performance increases substantially as wind penetration in power systems continues to increase to relatively high levels. It becomes increasingly important to accurately model the wind behavior, the interaction with other wind sources and conventional sources, and incorporate the characteristics of the energy demand in order to carry out a realistic evaluation of system reliability. Analytical methods using annual wind models have generally been used for reliability evaluation of wind integrated power systems. These methods do not recognize the seasonal and diurnal load following capability of wind. In this thesis, the system adequacy indices are first evaluated on an annual and seasonal basis and then a technique is developed to incorporate the diurnal load following capability of wind. Power systems with high wind penetrations are often connected to multiple wind farms at different geographic locations. Wind speed correlations between the different wind farms largely affect the total wind power generation characteristics of such systems, and therefore should be an important parameter in the wind modeling process. Another concern that arises is the lack of time-synchronized data, especially at the planning phase, which limits the capability of system planners to accurately model multiple correlated wind farms using simple analytical methods. A simple and appropriate probabilistic analytical wind model which can be used for adequacy evaluation of multiple wind-integrated power systems is proposed in the thesis. A simple analytical method to develop an approximate wind model of multiple correlated wind farms when time-synchronized wind data is not available is also proposed in the thesis. The methods to incorporate correlations in the adequacy evaluations of wind integrated power systems presented in the thesis are expected to be highly useful for system planners and policy makers as wind penetration continues to increase.