Modeling Of Multiple Wind Farms Output Correlation Based On Mixed Copula And Its Application On Power System Economic Dispatch

Wind energy is a kind of widely distributed,renewable and non-polluting green energy.There is huge potential for using wind energy to generate electricity.The utilization of wind power can effectively alleviate the energy crisis and environmental pollution.However,the active power of the wind farm is subject to the wind speed,and it will exhibit certain random characteristics.Because of the mutual geographical proximity of the wind farms in the same region,the active power output of multiple wind farms will exhibit certain positive correlation characteristics.These characteristics of wind power generation limit the further development and utilization of wind energy.With a view to better developing and utilizing wind energy,this paper will begin research and exploration on the correlation between wind power outputs.The work is described as follows:(1)Using a method combining ARMA model and time-shift technology to generate relevant wind speeds to obtain wind power output with high-to-low correlation,it is brought into the IEEE30 node system to carry out the calculation of node-voltage probabilistic load flow and reactive power compensation analysis of the power system.In order to analyze the impact of different correlation wind speed on the power system.The simulation results show that the correlation of wind speed has a great influence on the final probabilistic power flow calculation results.When the wind power output correlation level is high,the power system node voltage has a larger fluctuation range;for different related degrees of wind power generation In this case,the number of compensating capacitor groups required to obtain the same target value for reactive power optimization is slightly different.The higher the degree of correlation,the more reactive compensating capacitor groups are required.(2)In order to analyze the impact of different related degrees of wind power output on the power system,first use ARMA model and time-shifting technology to obtain wind power output data with high,medium and low correlation,and then on this basis Simulation analysis was performed in the IEEE30 node system.Taking the node voltage probabilistic power flow and reactive power compensation as examples,the influence of different related degree wind power output on the power grid was explored.The simulation results show that when the wind power output correlation level is high,the power system node voltage has a large fluctuation range;for different related degree wind power generation conditions,the compensation capacitance needed to obtain the same target value for reactive power optimization is obtained.The number of groups is slightly different,in which the higher the degree of correlation,the more reactive power compensation capacitors required.(3)Based on the established hybrid vine Copula model,the power consumption of the conventional unit under wind power output and the re-scheduled fuel cost of the power system under the random error scenario are taken as objective functions,and the power system considering the correlation of wind power output is performed.Dynamic economic dispatch,and the use of improved backtracking search algorithms for solving economic scheduling problems.In the IEEE 30-bus system,the economic scheduling analysis of the simulated wind power was conducted with the measured output of a certain wind farm in the United States.The simulation results show that,in the economic dispatch analysis,the random scene generation method that considers the correlation of wind power output can better reflect the actual wind power.The output situation,based on which the economic dispatch analysis is performed,can provide the dispatcher with more comprehensive dispatching reference information and help him to formulate a more reasonable dispatch plan.