Reactive Power Optimization Considering Static Voltage Stability

How to hold the security and economy balance of the power system operating, has been an important topic for power workers. Due to the rapid growth of the load and grid development is lagging behind,the system voltage stability margin is very lower than ever and easy to collapse when the system meets the serious contingencies.Reactive power optimization is an effective means of coordinating security and economy operation of the power system.The system voltage stability margin may be changed in the reactive power optimization process,therefore,it is necessary to consider the stability of the power system in reactive power optimization process. So the reactive power optimization incorporating static voltage stability is studied in this paper,the main research work is summarized as follows:(1)Provide an overview of the current study situation of the power system voltage stability and reactive power optimization,highlight shortcomings of traditional reactive power optimization and the mathematical model of reactive power optimization and the main algorithms for analyzing reactive power optimization.(2)The security and economy hybrid model of reactive power optimization is put out based on considering the active power loss,voltage quality and voltage stability margin,PSO algorithm in reactive power optimization of power system is studied,The test systems results show the model is right and the algorithm is feasible.(3)The system reactive power reserve capacity is an important index for the voltage stability margin,so a new reactive power optimization model with Static Security Constraints under Fault Condition is put out,whose objectives are to improve the system reactive reserve capacity and decrease the active power losse. Then the Benders decomposition algorithm is applied to decomposed the proposed model into a master problem and a subproblem,the master problem takes maximum reactive power reserve and minimal active power loss as objective function and consider static security constraints under normal condition,then the subproblem takes minimal total nodal mismatched power as objective function and consider static security constraints under Fault Condition. In order to improve the efficiency of solution by Benders decomposition algorithm,a parallel solution strategy and serial solution strategy combining with continuation power flow technique is given. Case studies are conduct with IEEE 39-bus system,the results shows the correctness of the model and the effectiveness of the proposed solution strategy.(4)The reactive power optimization models and algorithms mentioned in this paper are applied to practical power system-Chaozhou grid,analyzing the voltage stability margin and reactive power reserve capacity of Chaozhou grid in in summer 2013. Conclusion prove the proposed method can effectively improve the voltage stability of the system.