Research On Frequency Regulation Coordination Strategy Of Multi-type Flexible Resources Participating In Power Grid

In recent years,new energy power generation represented by wind power has developed rapidly with the support of national policies,and the proportion of new energy installed capacity in the power grid is increasing,which has made an important contribution to achieve the goal of "Double Carbon Target".At the same time,a large number of new energy access has also reduced the inertia and stability of the power system.The reduction of the proportion of traditional hydro thermal power units reduces the supply of traditional frequency regulation resources,and the increase of the proportion of new energy power generation brings more disturbances.If we only rely on the traditional generators to participate in power system frequency regulation,we need to increase the rotating reserve capacity of synchronous generator continuously,which will undoubtedly increase the cost of frequency control,or even difficult to achieve.Therefore,it is necessary to find new resources to assist the traditional hydro thermal units to participate in frequency control.The proportion of air conditioning load in the load side has been increasing in recent years,and there is great potential for frequency regulation by relying on communication and intelligent control technology.Energy storage batteries rely on the characteristics of rapidity and accuracy,which makes them have strong frequency regulation ability.The uncertainty of wind power generation output brings challenges to power grid frequency regulation,but it also brings opportunities.It can also participate in frequency regulation through transformation.On the whole,the rapid development of multi-type flexible resources represented by air conditioning load,energy storage battery and wind turbine has brought new ways and means to power system frequency control.However,the frequency regulation characteristics of these flexible resources are obviously different from those of traditional hydro thermal power units,and the frequency regulation characteristics are also different from each other.Therefore,it is necessary to explore the coordination strategy of multi-type of flexible resources participating in power grid frequency regulation.The research contents of this paper include:(1)This paper analyzes the frequency response characteristics of multi-type of flexible resources in the process of frequency control,and establishes the frequency control model of various resources.Based on the basic power regulation mode of flexible resources such as air conditioning load,energy storage battery and wind turbine,this paper analyzes the frequency regulation ability and frequency response characteristics of various resources,establishes the frequency control model of various resources,compares the control performance and economic performance of these flexible resources through simulation,and lays the foundation for the follow-up study of coordinated frequency regulation of multi-type of flexible resources.(2)Based on the frequency regulation characteristics of multi-type flexible resources,the optimal primary frequency regulation dead band setting scheme of multi-type flexible resources is designed.Firstly,this paper establishes a collaborative framework that can consider multi-type flexible resources participating in power grid primary frequency regulation,and makes an overall modeling of multi-type flexible resources participating in primary frequency regulation.Considering the dead zone of flexible resources participating in primary frequency regulation means that the order and frequency of participating in frequency regulation are different,which directly affects the performance of power grid frequency regulation.Then,the optimization model and solution method of optimal primary frequency regulation dead band setting in typical load disturbance scenarios are given.Taking the actual load data as the sample,a typical load disturbance scenario is constructed by analyzing the probability distribution law of the proposed combined statistical disturbance.Taking the control performance indexes of power grid frequency regulation as the constraint condition and the economic cost of power grid primary frequency regulation as the objective function,the optimization model and solution method of dead zone setting of multi-type flexible resources participating in primary frequency regulation are given.Considering that the resource types and parameters contained in different regions are generally different,this paper first gives the dead band setting method of multi-type flexible resources participating in primary frequency regulation alone.For the case that many kinds of flexible resources participate in primary frequency regulation at the same time,the dead zone optimization results are given based on particle swarm optimization method.In addition,the correlation between the cost of energy storage battery and the optimal dead time of primary frequency regulation is analyzed.(3)Based on the frequency regulation characteristics of multi-type flexible resources,the optimal allocation scheme of active power when multi-type flexible resources participate in secondary frequency regulation is designed.Firstly,a collaborative framework considering multitype flexible resources participating in power grid secondary frequency regulation is established,and an overall model of multi-type flexible resources participating in secondary frequency regulation is established,including AGC architecture and control model considering multi-type flexible resources participating in secondary frequency regulation.Then,the optimization model and solution method of active power distribution coefficient when multi-type flexible resources participate in secondary frequency regulation are given.The simulation results show that under the unified and coordinated control of AGC,multi-type flexible resources can assist traditional units to participate in secondary frequency regulation and contribute to improving the frequency stability level of power system.Finally,compared with the traditional active power allocation scheme according to adjustable capacity,it shows the superiority of the optimal active power allocation scheme proposed in this paper.