The Wide Area Protection’s Partition Of The Communication Reliability And The Current Differential Protection Fault Tolerance Method

With the development of power grid, power grid structure get more and morecomplex and need to be considered more operation modes. The traditional protectionsetting method is becoming more and more complex and difficult to protect power gridsensitivity and selectivity. Along with the wide area measurement technologydevelopment, the wide area protection technology matures gradually and becomes adomestic and foreign experts’ research focus. Based on the researches of the wide areaprotection literature, this paper studies on the wide area protection partition method of theregional centralized dispatching mode and the method of the current differential protectionfault tolerance after partition in districts. The main contents are as follows:Firstly, considering the protection communication circuit reconstruction, the paperstudies the wide area protection communication reliability calculation method and putsforward a kind of search method for all reconfigurable communication paths, usingbreadth-first search method. By the analysis of the wide area protection communicationnetwork running mode, the paper puts forward a kind of the wide area protection partitionmethod for the goal of reliability with the communication time constraint,.Secondly, in view of the traditional relay protection malfunction in the case ofexternal fault problem, the paper puts forward a new method to determine the currentdifferential protection, ensuring protection Fault tolerance when the current transformermeasurement data error. Different from the traditional method, which is through thecurrent value and the constant value comparative, this paper presents a method bycomparing the imbalance current of the components to find the maximum unbalancecurrent component as the short-circuit component. The method makes full use of the widearea measurement data, and has strong ability of preventing disoperation in the externalfault conditions. The paper uses the compensation method of the distortion in secondarycurrent to compensation the current value, In order to reduce measurement error range.Finally, due to the need of remote data collection, there may be some data errorsoccurring in the measurement and transmission of the wide area protection. For the question, the paper proposes a kind of wide area measurement data fault tolerance methodbased on the Kerchief’s law. This method not only ensures the rapid identification in thesimple data error case, but also ensures the reliability of identification in the complex dataerror conditions.This paper uses the matlab software to program on partitioning and fault tolerancemethod. The feasibility of the proposed method is verified.