Economic Dispatch With Wind Farms Based On Fuzzy Chance Constraints

In recent years,our country has continuously promoted the construction of ecological civilization,and wind power as a renewable clean energy has been continuously promoting the development of low-carbon economy.With the access of large-scale wind power,the intermittence,volatility and anti-peak characteristics of the output of wind turbine bring new challenges to the safe and reliable operation and economic dispatch of the power grid.For the above characteristics of the output of wind turbine,a multi-objective economic dispatch with wind farms based on fuzzy chance constraints is established in this paper.First,a typical economic dispatch model of power system is established,and the prediction curve of wind power is obtained by using the normal distribution wind speed model and wind speed-power curve.The output characteristics of wind turbines and the influence of wind farm access on power grid scheduling are also analyzed.Next,the carbon trading costs and the green certificates trading costs are introduced into economic costs on the basis of the traditional economic scheduling model,meanwhile,taking into account the start-up costs and the valve point effect costs of thermal power units.At the same time,the objective function of pollutant emission is taken into account in the model,which can further promote the low-carbon emission reduction of the system scheduling.Aiming at the intermittence and volatility of the output of wind turbines,the fuzzy chance constrained programming is introduced,and the output of the wind turbines and the load are regarded as fuzzy variables.In this way,the fuzzy chance constraint conditions are established,and the clear equivalence forms of fuzzy chance constraint are adopted to clarify the chance constraints.The improved multi-objective particle swarm optimization algorithm is used to solve the optimization problem.The influences of carbon trading price(green certificate trading price)and purchase margin of green certificate(purchase margin of carbon emission rights)and confidence level changes on the economic cost and pollutant emission of the system are analyzed by an example.The feasibility and effectiveness of the proposed model and algorithm are verified by comparison of different scheduling models.Finally,according to the anti-peak characteristic of the output of wind turbines,a wind-storage joint economic dispatch model is established.Taking the total economy costs as the first objective function,considering the operation costs of thermal power units and the green certificates trading costs in the cost function,the pumped storage costs and the power generation costs of the pumped-storage power station are introduced.The second objective function is the variance of the output of wind-storage joint dispatch,so as to enhance the effect of smooth windpower output by the pumped-storage power station.The example shows that the wind-storage joint dispatch can effectively smooth the output of the wind turbines.The feasibility and effectiveness of the proposed model and algorithm are analyzed by comparison of different scheduling models.