Reliability Assessment Of Power System Considering Wind Farm Correlation

Growing energy demand and environmental consciousness have re-evoked human interest in wind energy. As a result, wind is the fastest growing energy source in the world today. Due to the intermittency, volatility and randomness of wind energy, large-scale wind power integration will seriously threaten the safe and reliable operation of power system. Taking into account the correlation of wind speeds between different wind farms in the same area, it is necessary to consider the wind speed correlation when assessing the reliability of the power system including multiple wind farms.Focused on the reliability assessment of power system considering wind farm correlation, the main work of this paper includes the following aspects:Firstly, wind speed time series model and wind speed probability distribution model are established and methods for solving the corresponding parameters of wind speed probability model are also introduced. Aiming at the reliability assessment of power system including wind farms, wind farm reliability model is established, which includes wind turbine power output model, wake effect model and wind turbine outage model. Among them, wake effects model contains Jensen model, Lissaman model and partial occlusion model, and a case study is carried out to analyze the impacts of wind direction and wind turbines layout on wind farm wake effect.Secondly, considering the correlation of wind speeds between different wind farms in the same area, a reliability evaluation method of power system considering wind farm correlation is proposed. In this method, wind speed correlation model is established to simulate the wind speeds which have a certain correlation among multiple wind farms. Meanwhile, the wake effects of wind turbines are taken into account and sequential Monte Carlo simulation is used to simulate the status of each component. With multiple wind farms integrated to IEEE-RTS79test system, the impacts on power system reliability of wind speed correlation are studied. Finally, using MATLAB to write the corresponding programs, a case study is carried out and the simulation results show that:1) the correlation coefficient of wind speed increases, the fluctuation of wind farm power output increases;2) the reliability of power system including multiple wind farms decreases with the increase of the correlation coefficient of wind speed, that is the independence of wind speed can help improve power system reliability;3) wind farm scattered access is more advantageous than centralized access to help improve power system reliability;4) the wind speed correlation of wind farms should be considered when the wind power penetration or the peak load level is high during the reliability assessment of power system including multiple wind farms.