Reliability impacts of increased wind generation in the Australian national electricity grid

Abstract

Wind power penetration has been consistently growing and it has been rapidly becoming a significant generation technology in many countries. However, the intermittent and variable nature of wind energy is a major barrier in wind power commitment. Wind speed fluctuations and unpredictability can affect the operation and reliability of power systems. Therefore, the impact of integrating large volume of wind generators on the system reliability needs to be carefully investigated and the reliability contributions of wind farms require to be evaluated for better integration of wind energy sources. Because of intermittency and variability of wind energy, conventional reliability evaluation methods are not applicable and different techniques have been developed to model wind generators. However, most of these methods are time-consuming or may not be able to capture time dependency and correlations between renewable resources and load. Therefore, this research intends to improve the existing reliability methods and proposes a faster and simpler approach. In this approach, wind power and electricity demand are being modelled as time-dependent clusters, which not only can capture their time-dependent attributes, but also is able to keep the correlations between the data sets. To illustrate the effectiveness of this framework, the proposed methodology has been applied to the IEEE reliability test system. In addition, the developed technique is validated by comparing results with the sequential Monte Carlo technique. Due to an increase in the wind power penetration level in Australia, this research also investigates the contribution of wind power in the Australian power system from reliability point of view. In order to calculate the reliability contribution of wind power, the proposed framework is implemented on the national electricity market at two different reliability assessment levels: generation and composite system levels. Moreover, the impacts of strategies such as coordinating hydro units with wind farms on the reliability of wind energy are investigated. Similar to wind energy, photovoltaic (PV) penetration level is increasing in the Australian power system, which can affect not only the reliability of the power system, but also the reliability benefit of wind farms. Therefore, in this thesis the impacts of solar energy on wind load carrying capability under different scenarios are also assessed.