The Temporal-Spatial Fluctuation Characteristics Of Wind Speed And Application In Multi-Energy Complementarity

The fluctuation and intermittence of renewable energy pose a threat to the safe and stable operation of power grid.Combined power generation for multi-energy is an effective method to reduce the fluctuation of independent power supply,and it is also an important development direction of power system in the future.The study of fluctuation characteristics is prerequisite for multi-energy combined power generation,thus it is of great significance to study the multi-energy complementary characteristics based on the fluctuation characteristics.At present,the researches on the characteristics of fluctuation and complementarity exist some problems,such as imperfect evaluation index system,insufficient characterization of fluctuation and complementarity,and less research on the complementary characteristics of Wind-Solar-Hydro power.Considering the above problems,the main work of this paper is as follows:(1)The evaluation index systems of fluctuation and multi-energy complementarity are established.In order to evaluate the fluctuation and complementarity of time series in an all-round way,considering the local and global fluctuation characteristics,an evaluation index system of fluctuation is established from four aspects:instantaneous fluctuation,continuous climbing,discrete degree and maximum fluctuation.Based on this,a multi-energy complementarity evaluation index system is proposed.(2)The study of temporal-spatial fluctuation characteristics of wind speed time series is carried out.The daily-solar term's-seasonal time scale fluctuation characteristics of wind speed time series are comprehensively analyzed by using the fluctuation evaluation index system,and the Copula function is introduced to study the correlation between wind speed time series.The innovations are listed below:the fluctuation evaluation indices system is applied to comprehensively describe the fluctuation characteristics;considering the close relationship between solar terms and meteorology,the traditional Chinese solar terms are proposed as the time scale to carry out the research.The results show that the fluctuation evaluation indices system compensates for the shortcomings of the single indicator,and describes the fluctuation characteristics of wind speed time series comprehensively and meticulously.And the fluctuation characteristics are different in various solar terms,and the solar terms are more accurate and detailed than the months.Moreover,the spatial correlation degree of wind speed is related to the space distance and whether the units are adjacent.(3)The daily-solar term's-seasonal fluctuation characteristics and complementary characteristics of wind power,photovoltaic power and hydropower in a certain area of China are studied.The innovations are listed below:complementary characteristics is analyzed from the perspectives of the fluctuation characteristics of adjacent time windows and the continuous climbing of continuous time windows;a typical day screening method of t-distributed Stochastic Neighbor Embedding(t-SNE)dimensionality reduction combined with K-means clustering is proposed in order to solve the problem of data feature extraction with high dimensionality and complex data features.The results show that the proposed complementarity evaluation indices are more accurate and comprehensive than that of Copula function.The typical day screening method is scientific and reasonable and can be applied to study the daily characteristics of multi-energy complementarity.What's more,by studying the influencing factors of complementarity and the research of complementarity optimization,the results show that adjusting the proportion of wind power and photovoltaic power generation can reduce the fluctuation of combined power generation,optimize the degree of complementarity and improve the degree of complementarity at the same time.The research results of this paper provide a method for the study of the fluctuation and complementarity of renewable energy.It provides a reference for the planning and optimization of power grid dispatch of renewable energy combined power plants,and have important significance for reducing the fluctuation of renewable energy and exploiting the complementarity strength of combined power generation.