Research On Modeling And Correction Strategy Of Active/Reactive Power Coordinated Optimization In Transmission And Distribution Networks

Active/reactive power coordinated optimization adjusts active/reactive devices at the same time, which may enhance the system efficiency and security with a larger feasible region. Currently, there are some studies about active/reactive power coordinated optimization. However, these studies have some shortcomings. In transmission network, the most important power source generators didn’t get enough attention, which may endanger the generator running security. In ADN (Active Distribution Network), electric vehicles and energy storage systems are considered loosely, and load characteristics were ignored. This paper has done some research on modeling and correction strategy to improve the above defects.In transmission network, this paper considers generator capability limits in active/reactive power coordinated optimization, and derives the function relationship among constraint limits of reactive power output, active power output and terminal voltage. During optimization, constraint limits of reactive power output should be corrected according to active power output and terminal voltage, rather than maintaining constant. In this way, generators can always run in their safe region, and optimization results can be more objective and practical. This paper verifies the advantage of coordinated optimization and the necessity of considering generator capability limits. In view of the relationship between generation cost, generator economic parameters and active power output, this paper also analyzes the impact of economic parameters’changing of generators with different distances to load center on generator active power output after coordinated optimization.In ADN, considering the future development trend and the viewpoint that battery swapping mode has more advantages than charging mode, the BSS (Battery Swapping Station) is mainly studied. Based on the connection mode between charging/discharging device and battery pack and the charging/discharging characteristics, the model of BSS is established and involved in the ADN coordinated optimization model. The feasibility of BSS participating in coordinated optimization is verified, and a comparative study between BSS and Battery Energy Storage Station is presented. Take ZIP loads as an example to research on load static voltage characteristics. During optimization, through correcting power balance equations and related elements of Jacobian matrix, the optimization results can be more practical. And the influence of load static voltage characteristics on optimization is verified.