The Evaluation And The Optimization Of Dynamic Reactive Reserve Of The Grid With High Penetration Wind Power

Sufficient dynamic reactive power reserve is essential for maintaining the transient voltage stability and improving the anti-interference ability of the power system.With the rapid development of new type of the energy such as wind power,the three north regions of China have become the typical power grid with high penetration of wind power.The start-up modes of the traditional energy are failing because of the significant increase of the wind power.The impact of the operating characteristics of the wind turbine on the safe operation of the system is more major.This has an adverse effect on the voltage support capacity of the system.To ensure the safe and stable operation of the grid with high penetration wind power,the system needs sufficient dynamic reactive power reserve in real-time.This thesis focuses on the analysis of the mechanism of the influence of various components on transient voltage stability of power system.Then the necessity of the sufficient allocation of dynamic reactive power compensation in the area where the wind power is accessed concentrated is proposed.Lastly,the evaluation of regional dynamic reactive power reserve and the evaluation and optimization algorithm of effective dynamic reactive power reserve for weak links is proposed.The main work of this thesis can be attributed to the following four aspects.The reactive power and voltage characteristics of generator and load,and the influence mechanism of HVDC and various reactive power compensation devices on transient voltage are systematically analyzed.The calculation method of dynamic reactive reserve of single reactive power element,including wind farm,is analyzed,and the idea of evaluating the reactive power reserve of power grid that classifies areas is put forward.Aiming at subarea system,the identification method of partitioned leading reactive power source and weak section of voltage stability is put forward,which further simplifies the technical difficulty of reactive reserve optimization.The practical calculation method and steps of effective dynamic reactive power reserve assessment engineering related to the weak link of the system are proposed.Based on the transient stability calculation,the reactive power variation of each effective dynamic reactive power source in the transient process is calculated,and the effective reactive reserve of the weak link is obtained.Based on the dynamic security early warning platform and the power system comprehensive stability analysis program(PSASP),the above theoretical method is applied to the Tongliao power grid in eastern Mongolia.The weak link of dynamic reactive power reserve is selected,and the most effective dynamic reactive power supply group and effective dynamic reactive power reserve for weak link voltage supporting capacity are obtained,which verifies the effectiveness of the algorithm.The optimal control scheme of reactive power and voltage in local area power grid and the strategy of improving the dynamic reactive reserve in the area which Qingfeng wind electric sink system with great influence on the key nodes of the weak link of Tongliao power grid is assessed centralized are further studied.According to the characteristics of the system access network,optimizing reactive power compensation capacity,type and group selection that the wind power collection stations need to be configured.Proposed a optimization control strategy of the reactive power voltage which considering comprehensive of wind farms,wind power convergence station.On the basis of ensuring the basic static reactive voltage index,the system has as much dynamic reactive power reserve capacity as possible.