Research On Optimization And Control Strategy In The Province Under The Condition Of Large-scale Power Loss

With the continuous increase in the scale of interconnected power grids,failures such as large capacity unit shut down or UHVDC transmission system emergency lockout may cause large power loss in the power system which seriously affects the frequency stability of the system.And also may cause flow offset,which affects the safety and stability of transmission lines throughout the interconnected system.The solution to the large-scale power loss problems,conventional security control measures and manual repeatedly coordinated scheduling are still adopted in state grid.It is difficult to meet the precise and intelligent scheduling requirements of China's complex power system structure.So research on provincial regulation strategies under different fault scales following the principle of "unified scheduling,hierarchical management" has great significance.At first,according to the power system frequency response and the frequency requirements of China's power grid,quantitatively analyzes the impact of different quantities of power on the safety status of the power grid,and then uses the frequency offset coefficient of the rotating reserve capacity and different operating modes as the evaluation index of the system's own regulation capability.A method of dividing the system security level based on the amount of power loss is proposed.Based on this method,the basic content of the province's internal control is formulated under the framework of the integration and coordination of the sub-provinces of the province,which serves as the basis for the study of control strategies in the province.And start to study the control and coordinate strategy in the following article.Next,consider the trend of migration phenomenon to study the control strategy,the coupling factors between unit and load in the system are analyzed by combining the electrical division theory and directed graph theory.Take coupling load nodes as priority removal targets,and develop a load cutting scheme based on coupling factors.After the scheme be proposed,an example is given to verify the effectiveness in restraining the drift of the tidal current and reducing the scope of the accident.According to different situations at different security levels,the corresponding schemes are formulated to form a relatively perfect provincial control strategy.Finally,the scheduling strategy in the province is studied.Establish a power rebalance process and a scheduling model for system recovery after troubleshooting based on security constraints.The models include the spare capacity input,the power support outside the province,the load recovery model and the resection power recovery model,the spare capacity recovery model and the economic dispatch model.The principle of coordination at each stage is clearly defined,and the control strategy is used to build the timing framework and the overall process of the province's intra-provincial regulation strategies at different security levels.At last this paper selects examples using the particle swarm algorithm to solve the coordinative scheduling model,and compiling the province's internal control plan after the large-scale power loss.