Research On Power System Transient Instability Recognition And Control Strategy

Power system transient stability assessment and analysis have been an important research field in power system.According to the definition and classification of power system,transient voltage stability and transient power angle stability are two very important directions in power system transient stability analysis.Exploration and research in these two directions have been in full swing,and many excellent research methods have emerged in each,which are also of great research significance in actual scenarios.However,in the transient process of the power system,due to the interaction between the generator excitation system and the load dynamic characteristics of the transmission network,the two states of transient power angle instability and transient voltage instability are usually coupled together.At the same time,different instability states have their different generation and development mechanisms,and corresponding control measures need to be taken according to their characteristics.Therefore,accurate identification of transient instability is a key step for effective control.In response to these issues,the main research contents of this article include:1)Through the analysis of simple system voltage instability and power angle instability cases,the influencing factors of power system transient stability are studied,and the basic principles and research methods of two transient instability states are analyzed.Starting from the classic judgment method of power system transient stability,based on the consideration of putting two kinds of transient instability under the same system,and in order to better cover the various influencing factors in the system,the transient energy function method is selected to the study.The transient energy function under the classical model is introduced.2)This paper presents a method of power system transient instability state identification based on transient energy relation function.Based on the transient energy function of network structure preserving model,the transient energy relation functions of voltage and power angle are established by studying the energy power angle relation and energy voltage relation.Then,the expression of transient energy relation function is processed by means of average and normalization methods,and the sensitivity function index for identifying transient instability state of power system is obtained.Finally,for the single instability and coupling instability in the power grid,the sensitivity index is used to identify,and the corresponding control measures are applied according to the transient energy relation function to control,which verifies the effectiveness of the method.3)Based on the correct identification of the dominant instability state of the power system in the transient process,this paper studies the emergency control methods that need to be implemented.For the transient power angle instability state,the machine cutoff control measures are taken,and the machine-cut control location is determined based on the transient power angle relationship function;for the transient voltage instability state,load-cutting control measures are taken,and the switch is determined based on the transient voltage relationship function.Load control location.At the same time,based on the theory of transient energy transmission and flow,the calculation method of emergency control quantity is proposed.Finally,a complete power system transient instability identification and control strategy is formed,and a complete and effective strategy from power system transient stability analysis to identification to control under the transient energy function system is realized.