Optimal Dispatch Strategy Of Wind Integrated Power System

Power system optimization dispatch is a crucial section to maintain power system security and stability operation and allocate generation resources in power system.With the rapid development of wind power installed capacity,the wind power penetration rate in the power system progressively increased which aroused some new challenges to the custom power system dispatch method for the uncertainty and volatility of wind power.Effective wind power prediction is the primary method to deal with the badness impact of wind power,while up to now the forecasted method cannot provide accurate wind power prediction values,so the uncertainty of wind power should be reasonable processed in the dispatch model.As mentioned above,in the dissertation some research works about wind power analysis and power system dispatch model considering wind power have been done as follows.Becasuse the meteorology inertia,the output power of wind farms have significant correlation in some area.The correlation between wind farms should be considered when simulate wind power in some models,but the traditional correlation analysis method analyses the correlation between variables based on the normal correlation structure for the analysis method prior-assumed the variable probability distribution as normal distribution.Because the distribution of wind power is not normal,it is not reasonable to analyses wind power correlation based prior-assumed normal distribution.In the first part of the dissertation,the correlation degree and correlation structure of measured wind power has been analyzed,then a mix copula function model by which can construct joint distribution function has been built to analyze wind power correlation which considering the correlation structure of different copula,and at last the dependence include the tail-dependence of wind power has been analyzed based on the mix copula model in order to increase cotrol level of wind power correlation.Medium and long-term unit commitment can coordinate the generator resources in longer time scales,with the raipd development of wind power and the build of Chinese middle electricity market,the influence of wind power and market electic quantity should be considered in the custom unit commitment.In the third part of the dissertation,the trding categories about electric quantity in the middle electricity market and the settlement price about scheduled electric quantity and market electric quantity which will influence the unit commitment model have been analyzed first,then a unit commitment model consider electricity market with scheduled electric quantity and market electric quantity has been build.In the model,simulated wind power scenarios which considering tail-dependence and rank correlation from the previous wind power correlation analysis,the “pay as bell” and “benchmark price” electricity pricing mechanism has been considered.And the model based on differential electric quantity which transition from balanced energy to coordinate the power purchase cost and coal consumption of the system,and the unit commitment model can be used to evaluate the percentage of market energy under different wind power.penetration rate.Wind power forecasting software which provide wind power value can be used as reference value in short-term dispatch model,but as the wind power ramp event occurred the custom wind power forecasting cannot provide credible forecasting value,it's need to special deel with wind power in dispatch model integrated wind power.In the forth part of the dissertation,the uncertainty of normal wind power forecasting and ramp event has been analyzed,then the uncertainty set based on six-point fuzzy number was used to describe wind power.The fuzzy robust dispatch model which considering ramp event constraints integrated wind power was bulid under the basic of fuzzy dispatch.The model can balance the insufficient of reseve capacity and economics when the wind power ramp event occurred.Less-predictability of wind power request reasonable considering its uncertainty in power system dispatch model.In the fifth part of the dissertation,less conservative robust optimization framework has been built based on robust optimization,then power system light robust optimization dispatch model considering wind power has been build by defining tolerace index of nominal scenario economics.In the model,wind power prediction value scenario was used as nominal scenario,the uncertainty of wind power was described by previous prediction intervals,and the robustness of dispatch solution was pursued restrained by the specific tolerance of nominal scenario objective function deterioration which can balance the solution reasonable and economics of object funtion.