Research On Key Technologies Of Primary Frequency Regulation For Grid Connected Wind Farms

In recent years,wind power generation has attracted much attention and developed rapidly,and the momentum of installation and grid connection is also very strong.However,wind energy has the inherent characteristics of randomness,volatility and intermittence,which leads to large fluctuation of wind farm output power.Large scale wind turbines integration will affect the safe and stable operation of the power grid.In order to ensure the safe operation of the power system,the power grid requires the wind farms to conduct primary frequency regulation.In order to make the grid connected wind farms have the ability of primary frequency regulation,this paper puts forward the methods of scheduling optimization of wind turbines active power inside the wind farm,and installing energy storage devices outside the wind farm to participate in the primary frequency regulation of wind farm,and on this basis,develops and designs two kinds of software.Firstly,the optimal method of active power dispatching of wind turbines based on double-layer flower pollination algorithm is proposed.The classification method of wind turbines is studied.According to the performance evaluation indexes of wind turbines,the performance of wind turbines is evaluated and classified.The multi-objective power dispatching optimization model of wind turbines start-up and stop states and active power distributions is established.A double-layer flower pollination algorithm is proposed.The multi-objective power dispatching optimization model of the wind turbines is solved by using the algorithm.Finally the optimal operation state of the wind turbines and the optimal active power dispatching results of the wind turbines are obtained.The effectiveness and feasibility of the method are verified by an example.The results show that the proposed power dispatching method can meet the dispatching instructions of the grid to a certain extent,and make the grid connected wind farm have the primary frequency modulation capability.Next,a hybrid energy storage capacity optimization method of battery and flywheel based on adaptive chaotic-particle swarm optimization algorithm is proposed,and the corresponding charging and discharging strategies are proposed to stabilize the wind power fluctuation.In order to minimize the economic cost of battery and flywheel hybrid energy storage configuration,a hybrid energy storage capacity optimization mathematical model is established,and an adaptive chaotic-particle swarm optimization algorithm is proposed.The algorithm is used to solve the hybrid energy storage capacity optimization mathematical model,and the optimal hybrid energy storage capacity of battery and flywheel is obtained,Finally,the charging and discharging strategies of hybrid energy storage device are proposed.Using the optimal results of hybrid energy storage capacity and the proposed charging and discharging strategies of hybrid energy storage devices,the fluctuation of wind power is effectively suppressed,so as to achieve the purpose of grid connected wind farm primary frequency regulation.Then,the wind farm primary frequency regulation active power online scheduling optimization software is designed,and the development processes and functions of the software are introduced in detail.Six interfaces are designed in the software,including login interface,command input interface,system parameter setting interface,1#～11#wind turbines active power dispatching optimization interface,12#～22#wind turbines active power dispatching optimization interface,and 23#～33#wind turbines active power dispatching optimization interface.The online scheduling optimization of wind turbines active power is realized.Finally,the wind farm primary frequency modulation hybrid energy storage capacity optimization configuration software is developed,and the development processes and software functions are introduced.There are six interfaces in the software,including login interface,data selection interface,system data calculation interface,self selected data calculation interface,hybrid energy storage capacity optimization results interface and hybrid energy storage system wind power stabilization results interface.The graphical visualization of energy storage capacity optimization results and stabilization effects are realized,which make the effect more intuitive.