Fast Identification And Transmission Limit Analysis Of Key Section Of Power System

At present,with the increase of the national electricity and the development of economy,the scale of the power system is becoming larger and larger,the structure and the operation mode of the power system are becoming more and more complex and changeable.Accordingly,higher requirements are put forward for the reliability of power system safety operation.The monitoring and control of each component in the system is a huge task but not necessary.The key transmission section is the weak link in the power system.And many serious power outages are caused by the cascading failure of the line on the key section.Therefore,it is of great practical significance to study the key section of the system.Research in this field is also one of the hot spots in the present study.In this paper,we mainly research on the rapid identification and the transmission limit of the key section.In the existing recognition algorithms of the key section,the fuzzy clustering method does not need to be given a number of categories.So it can effectively avoid the subjective influence of human factors and get a wide range of applications.This method is mainly divided into three steps: the determination of initial section,the determination of candidate critical section and the determination of the critical section.In determining the candidate key transmission section,the paper puts forward the concept of "transfer station".Based on the automobile relay model,the algorithm can quickly search the shortest circuit which contains a two lines,avoiding the complex matrix operation.In determining the critical section,the active power flow is defined on the basis of the power flow transfer factor.This index considers the situation that the load flow of the light load line is reverse increased,which avoids the leakage of the line.The effectiveness of the proposed algorithm is verified by the example of IEEE standard node system.The transmission capacity of critical section restricts and affects the power transmission of the power grid.In this paper,the transmission limit value of the critical section N-1 is calculated,and the results are compared with the PSASP calculation results.The algorithm of the transmission limit based on the generalized generation distribution factor(GGDF)is proposed.The algorithm considers the balance machine control on power flow,so there is no need to ensure that the total generating capacity is constant,more in line with the actual working conditions.Transmission power limit of transient stability is an important index to measure system stability.In this paper,the calculation of section transient stability limit transmission power is analyzed and the calculation method of ultimate transmission power is proposed.The algorithm takes the system transient stability margin of the section as the goal.When the stability margin of the algorithm is close to the critical value after several iterations,the power of the section is the transmission limit value.The effectiveness of the proposed algorithm is demonstrated in the IEEE39 node system.