Coordinated Control Strategy Of Large-scale Intermittent Power In Gird

With the depletion of fossil energy and increasing pressure of environmental protection,large-scale of intermittent power supply,such as wind power and photovoltaic,being used in the world for its rich resources and little pollution,have become more and more popular among countries.However,intermittent power has its characteristics of volatility and randomness,having caused great influence on the safe and stable operation of power system.Therefore,it is very important to study the coordinated control method of large-scale intermittent power supply connected to the grid.Firstly,starting from the features of wind and photovoltaic power,compositions,theory and mathematical model of the wind power and photovoltaic power generation system are expounded,and the prediction method of wind power and photovoltaic is analyzed in the paper.Meanwhile,the energy storage mathematical model and its application status are introduced,as well as a brief analysis of the position of the energy storage system in the power system.Secondly,the load type of automatic generation control(AGC),frequency control of power grid are introduced.The possibility of intermittent power system participating in frequency control of system,research status of intermittent power supply to power grid dispatching in domestic and abroad are analyzed.The paper put forward the coordinated scheduling strategy of intermittent power based on multi-time scale power prediction and real time control of active power of steady state of power system,and the lag frequency compensation strategy of wind plant and photovoltaic power station in situation of load fluctuation.Meanwhile,the paper expounded and analyzed the type and its reason of the fault of power grid and intermittent power.As to the regular fault of power grid,based on constant voltage control and voltage collapse prevention of voltage stability margin,taking each advantage of TSC,SVC and STATCOM,the paper put forwards parallel reactive compensation,enhancing the capacity of low voltage ride through of wind plant and photovoltaic power station.For the disconnection of intermittent power,the paper take control strategy of power shortage rapid compensation to maintain power grid stability.In this paper,the system simulation model of state of steady,load fluctuation and the fault of power grid are built,and simulation experiments are being carried out.Simulationresults show that,under steady state,intermittent power optimization scheme is realized by introducing the on-line rolling module and genetic algorithm,and through active power real time control,intermittent power improved the completion of the scheme plan.According to different load fluctuation,the corresponding control strategy is adopted to meet the demand of system frequency modulation,meanwhile,intermittent power is indirect participated in it.In the condition of fault of power grid,the output of SVS,which can prevent the intermittent power voltage drop sharply,played a certain active role in voltage recovery and improved the voltage stability of system.