Research On Reliability Of The IEC61850-based Relay Protection System

Nowadays, in China the electric power industry puts its importance on the research and innovation about power transformation and transmission with voltage. As the very essential element of power transformation part of power system, the digitized transformer substations will become the mainstream in power transformation area. In the running system of digitized transformer substation, the issue about the reliability of electric power relay protection system should be researched.Currently it becomes a critical problem how to develop the reliability of the electric power relay protection system. It can keep the protection system protecting high-tension line in safety and efficiency that this problem can be evaluated. There’re mainly two entry points for the problem as follows:1st, the sensors of system must be properly selected and fixed to assure system that the sensitivity for detecting the power line’s fault can be developed and the probability of error action can be reduced;2nd, the algorithm for reliability asses in system daily maintenance must be properly selected to assure system can be maintained timely and accurately.This paper mainly does the research on a hot issue, the reliability issue related to the digitized IEC61850-based electric power relay protection system. The main direction is researching the reliability from two respective expanded points of developing it with the mutual inductor selection and accurately assessing it with a high efficient PC optimized algorithm.Firstly, the paper introduces the current situation of the development of national digitized transformer substation then it analyzes some problems which exist in the relay protection part of these substations and the national current situation of the relative research on the system’s reliability. Then it argues the feasibility of an idea about developing relay protection system’s reliability with optics current mutual inductor OCT. Also for the assess of reliability, it depicts the theory and advantages of asses by minimal path sets traversal method and special path sets disjoint method. Aiming at the fuzzy of the appearance of the error in the electronic power relay protection system, the user-service PCs which maintains the system can make right judgment and perform asses. Meanwhile, the paper also put forward that the asses algorithm can be optimized by "dynamic array" which can make a process called dimensionality reduction for the data in the path sets matrix in the program so that the PC’s efficiency for asses work can be boosted.Finally, the paper simply introduces the dynamic fault tree. The algorithm can verdict and deal with the system’s fault and build a module for PC’s traversal method doing the ability-asses so it can help maintainers work. Because of the almost mature development of dynamic fault tree, the paper only discusses the logical algorithm’s theory and feasibility without deeper research.