The Research Of Power System Transient Stability Analysis Based On Trajectory And Trajectory Sensitivity

Power system is a strongly nonlinear complex system. Some components maybe running under the condition of the close to the stability limit. In the case whereany component fails may endanger the stability of the system, severe cases can evenlead to large area and longtime of power outage, causing irreversible damage tonormal life of people and economic development. Therefore, the research to ensureand improve transient stability of power systems approach is an important subject inpower system.Trajectory sensitivity is a mathematical tool quantitatively described theinfluence of parameters on the dynamic system behavior, it contains a wealth ofsystem dynamic information. Accurate and fast calculation of trajectory sensitivity isthe basis of analysis the transient stability. This paper verifies the feasibility of directcalculation of power angle relative generator active output based on trajectorysensitivity in a single machine infinite system, and shows that this method is notrestricted by the generator model theoretically.The trajectory sensitivity can be the reaction of generator active power changeon the influence of the angle. When the system is close to the stable boundary, with avery high peak sensitivity, which can estimate the critical output of the machinebased on the value of the trajectory sensitivity. Using a single machine infinitesystem, WSCC3machine9node system and10machine39node system to verify theeffectiveness of the proposed method.In power system transient stability analysis and control, the critical clearancetime is normally acted as stability index. Adjust the active power in the limit range ofgenerator to improve the system stability, and the solution satisfy the stability indexis often more than one. Considering the operation economy of the system, generatoradjustment at the lowest total cost is the scheme of active efforts to redistribute required in this paper. This scheme can not only successfully eliminate the potentialrisk of stable operation, improve the stability of the system, but also consider theeconomy, is a kind of effective prevention and control measures of transient stability.