Research On The Analysis And Improvement Of The Flexibility Of Regional Power System Schedulable Resources

In line with the tendency of the modern society of green,low energy consumption and sustainable energy,the share of wind power,photovoltaic and other clean energy in the power system is fast on the increase.However,this kind of energy generation is affected by complex environment,and the fluctuation,intermittency and uncertainty of power output adversely affects the reliable and steady operation of the grid.At the same time,the types and proportion of demand-side electric loads increase,resulting in the increasing peak-to-valley load difference,which brings pressure on the energy side to generate electricity to meet the load demand,and also affects the stable operation of the grid.To describe these problems,the concept of power system flexibility is developed to measure the power system’s ability to respond to load and renewable energy fluctuations and uncertainties in a timely and accurate manner.Therefore,in this paper,it is important to analyze power system flexibility and study flexibility enhancement techniques to improve the ability of power systems to cope with intermittent energy and load fluctuations,etc.This paper addresses the above issues as follows:(1)This thesis performs an analysis of the sources of flexibility requirement within the power system and the flexibility supply capacity of flexibility resources,and quantify the flexibility demand model and the flexibility supply model for flexibility resources such as thermal power,energy storage,and electric hydrogen production.Combine the above quantitative model to propose system flexibility supply and demand balance evaluation indexes.At the meantime,the system’s inherent flexibility potential is fully mobilized,and optimization indicators that take into account the inherent flexibility of the system are proposed.(2)A two-layer optimization model for power system flexibility is developed in this thesis.The above two indicators are taken as the optimization objectives.Meanwhile,from the perspectives of reducing flexibility demand and improving flexibility supply capacity,respectively,a flexibility demand optimization model based on scenario clustering in the upper layer and a flexibility optimization scheduling model considering source-load correlation in the lower layer are established.The two models jointly enhance the flexibility of the system.Among them,the upper-level flexibility demand optimization model clusters scenarios according to the different fluctuations of wind power and load of the system throughout the year,and formulates targeted demand reduction strategies for the flexibility demand characteristics of different typical days;the lower-level flexibility optimization scheduling model takes into account the relevance of wind power output to load in a typical day,and uses this as a basis for rationalizing the scheduling strategy for each flexibility resource in the power system.After authentication,the method proposed in this paper fully takes into account various operating conditions in the system,accurately formulates appropriate control strategies according to different conditions,effectively reduces the flexibility requirements of the system,at the same time,fully schedules flexible resources in the system,reasonably arranges power generation plans,and provides sufficient flexibility for the system under the guarantee of secure and steady work in each unit.