Research On Wind-hydro Power Generation Coordination Scheme With The Accumulation Of Meteorological Forecast Uncertainty

The volatility and randomness of wind energy resources leads to the randomness and intermittency of wind power generation.Large-scale wind power integration into the grid will have a greater impact on the operation of the power system.In order to solve the problem of wind power grid connection caused by wind volatility and randomness,improve wind power utilization and promote the development of new renewable energy,recognizing the complementary advantages of wind power and hydropower,the coordinated operation of wind power generation is to promote the absorption of new energy favorable way.The article starts with the joint operation of wind and hydro power generation.Considering that weather forecast is the key support link of wind and hydro power generation dispatch,the uncertainty of weather forecast directly affects the output power of wind power and hydropower,thus affecting the scientificity of dispatch decision.Most researches use constant probability distribution or fuzzy parameters to represent the uncertainty of meteorological forecast,ignoring the relationship between the uncertainty of the weather forecast and the forecast period,it is difficult to accurately and objectively reflect the uncertainty of the weather forecast,thus affecting the short-term scheduling decision-making effect In this paper,the uncertainty accumulation model of weather forecast is proposed,and the coordinated operation plan of wind-hydro power generation is proposed based on this model.The main content of the paper is as follows:Based on the characteristics of the increase of the uncertainty of weather forecast with the forecast period,evolution process of meteorological forecast is analyzed,and building conditions and assumptions of uncertainty accumulation model is put forward.Through defining the evolution of forecast,distribution characteristics of meteorological parameters considered forecast uncertainty accumulation is developed,which is used to describe the relation between weather forecast uncertainty and foreseen period,and lay the foundation for subsequent establishment of wind power and hydropower generation output model and optimization scheduling of wind power and hydropower based on the meteorological forecast uncertainty accumulation model.Wind power and hydropower generation output model are established based on the meteorological forecast uncertainty accumulation model.Estimate of the wind power output is mainly based on the forecast of wind speed and wind turbines rating data.Output characteristics of wind turbines determines that its output model is hybrid random variable model,which needs to compute the fan power output probability density function and calculate the expected value,and finally get wind turbines output.Estimation of hydropower output is mainly based on the data of reservoir capacity and runoff,and the actual runoff is calculated by using MGF as the tool according to the reservoir runoff prediction model,and finally the output of the hydro turbine unit is obtained.Based on the forecast uncertainty cumulative model,the optimal dispatch of wind and hydro combined power generation is carried out.In order to ensure the self-efficiency of hydropower in coordinated operation,the multiple objectives of joint output of wind and hydro,the abandoned power of hydropower,and the guaranteed output of hydropower are comprehensively considered.The mid-term coordination model of wind-hydro power generation is introduced.The approximate random variable of the cumulative net flow is solved by the moment generating function,and the storage opportunity constraint is converted into a deterministic equivalent class form to facilitate the model solution.The example uses genetic algorithm to verify the effectiveness of the proposed scheme,and analyzes and verifies the impact of the chance constraint confidence,the variance of runoff forecast evolution,and the effect of the forecast period on the coordination effect.