Modeling Of Wind Farm Power Output Probability Distribution In Complex Terrain Based On Clustering Algorithm

Global decline in fossil fuel reserves, damaging effects of global warming, and rising energy demand due to increasing population have necessitated the need for more research and development of low-carbon sources of energy. Thanks to the environmental benefits, technological advance of wind power and government incentives, wind energy has become the fastest growing alternative energy source of the global renewable energy industry. Due to the output power of wind turbine generators (WTGs) always fluctuates because of the random nature of the wind speed, the increase in wind farm capacity makes the impact of wind power fluctuations on the system stability more considerable and even may lead to power system collapse in unsuitable situations.Focuse on the characteristic of wind farm power output, the relevant basic theories of reliability assessment of composite generation and transmission system containing wind farms were firstly introduced in this paper. Based on the research of the partial wake effect model of two WTGs at the different altitudes in complex terrain, a multiple wake effect model in complex terrain was established, which could be applied to describe the wake effect between different WTGs in kinds of complex terrain as well as in flat terrain.Secondly, taking the power output characteristic of WTG, the multiple wake effect model in complex terrain, the outages of WTGs, especially the outages of connection cables into consideration, a wind farm reliability model which considered the outages of connection cables was presented. Using Weibull distribution to simulate the wind speed and sequential Monte Carlo to simulate the outages of WTGs and connection cables, the models are implemented in MATLAB and the results show that the multiple wake effect model in complex terrain can accurately describe the wake effect between WTGs and the reliability model which taking the outages of connection cables into account improves the accuracy of the original reliability model.Finally, through analyzing the probability of WTG output power and combining the multiple wake effect model in complex terrain with the wind farm reliability model which considered the outages of connection cables, a model of wind farm power output probability distribution based on clustering algorithm was established. This model combined the randomness of wind energy with the probability of wind farm power output and made a wind farm equivalent to a multi-state conventional unit with clustering algorithm as a method. Taking IEEE-RTS79test system as an example, the results show that the model can effectively simulate the power output of wind farm as well as be used for reliability evaluation of power system with wind farms, and ensure the accuracy.