Methods Of Static And Dynamic Recative Power Sources Optimal Allocation For Power System

The development of energy internet has become an inevitable trend due to non-balance of energy distribution and power shortage in economically developed areas.The interconnection between regional power grids has many advantages in improving the reliability of power supply,improving the utilization rate of power generation equipment and improving the economic operation of the system.But once the backbone connection line failure,may cause the interconnection of the regional bus voltage is reduced,and even lead to voltage collapse,eventually result in a large area blackout.In recent years,the rapid development of reactive power support can quickly provide a large number of reactive power,improve the voltage magnitude,reduce system active power losses,etc.And the voltage level of application is getting higher and higher.However,because reactive power is expensive and can not be fully configured,it is of theoretical significance to study the optimal configuration of reactive power in power system,which is of great significance to the actual operation of power system.The specific problem studied in this paper is to optimize the configuration of static and dynamic reactive power in the power system from the point of view of the security of the power system,so that the system can resist the threat of serious faults threatening the voltage safety.In order to optimize the configuration of the reactive power in large-scale complex power network,some reasonable simplification should be done to reduce the computation time and calculation amount.In this paper,the methods of predictive accident analysis are used to propose the static and dynamic accident severity index and the bus vulnerability index to select the serious fault set and fragile bus set of the system.In the dynamic accident analysis synthesis,the bus voltage drop degree is taken into account,Low voltage duration and voltage recovery time.Then,the static and dynamic voltage / reactive sensitivity of the nodes are calculated by the sensitivity analysis method.The merits of the compensation effect of each node in the system are determined by the ranking of the sensitivity indexes,and then the pre-compensation region of the reactive power source is determined.The optimization of static and dynamic reactive power is used to solve the optimal compensation capacity of the reactive power supprot,respectively,on the basis of obtaining the serious fault set and the preselected compensation region.In the static reactive power optimization configuration process,from the economic point of view to minimize the capacitor investment objective fun ction.This paper presents the concept of dominant fault,which is a subset of the serious fault set.It can fully reflect the characteristics of the serious fault set,and then proposes a multi-fault based on the dominant fault.Static Reactive Power Optimization Analysis.Considering the mixed characteristics of discrete variables and continuous variables in power system,static reactive power optimization is considered as a mixed integer nonlinear programming problem.The reactive power optimization mode l is solved accurately by using branch-and-bound method and primal-dual interior point method.In the process of dynamic reactive power optimization,this paper analyzes the shortcomings of the basic optimization model,and proposes the concept of dynamic voltage trajectory violation integration to limit the magnitude of dynamic voltage of buses during the optimization process,and then forms voltage stability constraint via trajectory violation integration.Afterwards adding the generator power angle stability constraint to the optimization model.A method of mean variance mapping is used to solve the dynamic reactive power optimization model.The proposed method can limit the solution vector to the search range precisely by the mapping function,and has the advantages of fast convergence speed and avoiding local optimization.By simulation analysis of IEEE 39-bus system,the validity of the proposed reactive power optimization allocation method is verified,and an actual grid is taken as an example.The proposed method is used for contingency analysis,sensitivity analysis,static and dynamic recative power sources optimal allocation.The calculation results show that the proposed allocation scheme can enhance the voltage quality of the target power grid,and expand the new idea for the engineering application of reactive power.