Research On Dynamic Tidal Current Transfer In Electromagnetic Looped Network After Fault

With the development of power system and the construction of power network structure,Aparalleling operation structure of high voltage grade and low voltage grade transmission lines may emerge in the same regional network to satisfy the requirements for long-distance transmission.The structure,also called electromagnetic looped network,can enhance the transmission capacity and power distribution reliability under certain conditions.However,it may become a hidden operation hazard in the electric power systemThe instability and even the collapse of system voltage may generate from the strength of power transmission networks,the transmission level of power,load characteristics as well as the regulation and control device of reactive voltage,etc.Power flow transferring phenomenon,which is after the power system fault,is also proved to be a innegligible factor influencing the voltage stability in the operational process of power system.Among the flow transferring phenomenon,that of generator branch is of special concern.The traditional power flow transferring research is limited to a degree.The static safety and stability analysis method adopted currently uses the generator of the balanced node and the PV nodes to calculate the constant power load.However,the generator power can not be determined during the power flow transferring process after the disturbance fault in system.In this case,considering the potential's qeality of being free from mutation when sudden disturbance occurs,the generator is supposed to be the potential model when the power system operate,it would make the analysis of voltage stability phenomenon be more rational if taking into account the static characteristics of the load.In view of the facts mentioned above,we improve the safety and stability analysis method.At first,we will adopt the potential power supply and composite load to establish dynamic power flow model.Next,we will use the characteristics of fixed-point iteration and also consider the non-swelling characteristic of Jacobi iteration to solve the model.While taking the disturbance fault of generator into account,the iterative algorithms feature of the model can not only embody the non-abrupt change characteristic of generator's potential,but also reflect the phenomenon that node voltage drops and current increases after the fault,therefore highlighting the nonlinear phenomenon after the fault.Electromagnetic looped network is an important hidden trouble about security in power system operation.In this paper,after the establishment of dynamic power flow model for IEEE14 node test system and simple electromagnetic looped network,we used the fixed-point'snon-swelling feature of Jacobi iteration to solve it.The method presented in this paper,whichmake up for the lack of analysis in power system's safety operation,also can be proved to be correct and practical though the analysis of the result.