Optimal Allocation Of Wind-Solar Complementary Capacity Based On Probabilistic Power Flow Under Multi-type Hydropower Coordination

Developing renewable energy is an great strategic target of Our Country,"Thirteenth Five-Year Plan" of renewable energy development issued by the National Development and Reform Commission established the idea of "accelerating the development of non-fossil energy including hydropower,and enhancing conversion utilization of renewable energy such as wind power and solar energy actively".In response to national energy policies,Hunan Province has actively developed wind power and solar power generation in recent years.As Hunan is relatively poor in primary energy and highly dependent on other provinces,the development and utilization of renewable energy has become a top priority.The richness of resource is the precondition to measure the development and utilization of renewable energy.The uneven distribution and unreasonable allocation of renewable energy will bring many problems to the safe and stable operation of power grid and result in waste of resources.Therefore,this paper carres out characteristics analysis of renewable energy,probability power flow distribution and optimal allocation of installed capacity of wind-solar power station in view of the hydro,wind and solar renewable power generation resources in Hunan Province.Firstly,the output stochastic models of wind and solar power generation are established,then the combined probability distribution of wind-solar power output is established based on the Copula theory,and the eorrelation and complementarity of wind-solar power output are simulated in detail.The spatial and temporal distribution of hydro,wind and solar power resources in Hunan province is described in detail by using statistical method based on the historical monitoring data provided by meteorological departments,which mainly involves the multi-precipitation and less-precipitation areas in Hunan province,variation of wind speed in each region,the distribution of solar radiation in three similar regions,and the characteristics of hydro,wind and solar power installed capacity,grid-connected capacity and output in each region are also described.The analysis lays a foundation for the following research on the influence of wind and solar access on the probabilistic power flow distribution of Hunan power grid and the optimal capacity allocation of wind and solar power stations.Secondly,the linearization model of node injection power and branch power is established,and the application of semi-invariants and Gram-Charlier series expansion method in probabilistic power flow is analyzed.Based on the analysis of the space-time distribution and output characteristics of hydro,wind and solar resources in Hunan province and the joint probability distribution of wind and solar output based on the Frank-Copula function established in Chapter ?,the power flow calculation and analysis of wind and solar power connected to Hunan 500kV system in three scenarios are carried out by using semi-invariant and Gram-Charlier series expansion method.The steady-state power flow characteristics of Hunan power grid without wind-solar access,wind power alone access and wind-solar complementary access are compared,which provides a guarantee for the safe and stable operation of the power grid in the optimal capacity allocation of wind-solar power stations considering multi-type hydropower coordination.Finally,the paper establish output models of runoff hydropower,cascade hydropower and pumped storage,and a operation strategy of multi-type hydro-thermal-wind-solar combined system is proposed further.On this basis,considering the analysis of resource characteristics,output characteristics and wind-solar complementarity characteristics in chapter ?,and the analysis of the influence of wind-solar access on probabilistic power flow of Hunan power grid in Chapter ?,the paper establish an optimal capacity allocation model for wind-solar power plants with multi-type hydropower coordination,which objective is to minimize the cost of construction of wind-solar power stations,the cost of operation and maintenance of combined systems and the cost of purchasing electricity,and to maximize the proportion of wind-solar power generation to load demand.The operation of multi-type hydropower stations,reservoir capacity with the constraints of node voltage,branch power and transmission power.Based on the equivalent wiring diagram of the 500kV line of Hunan power grid,wind and solar power generation are respectively connected to Sudan and Luocheng nodes in the region with relatively abundant wind and solar resources in Hunan,an improved particle swarm optimization(PSO)algorithm based on extreme learning machine is used to simulate,and an optimal installed capacity allocation scheme for wind-solar power plants is obtained.The operation of the combined system consists of three different types of hydropower,thermal power and wind-solar power on a typical day is compared.It is concluded that runoff hydropower,cascade hydropower,pumped storage,thermal power and wind-solar combined system have the largest installed capacity,the best daily operation economy of the system,and the highest proportion of wind-solar power generation in the load demand.