Design And Development Of The Line Protection Analysis And Evaluation System

The digital fault recorder is the important equipment in power system for fault and transient data recording. When faults or oscillations occur, the recorder data plays an important role in analyzing the fault cause and testing the operation of protective relays and automatic devices.By the available recorder data acquisition system, we can get detailed and actual waveform and data including mass information, which have large analytic potential. So designing and developing fault analysis software, and further analyzing the fault information, are of great importance for testing the operation of relays, fixing on fault cause, isolating fault and resuming power supply. And it also offers forceful supply for the amelioration of the protection principle.In this research subject, a system which can be used to analyze and estimate the line protection scheme is designed and developed .The author uses the RCS-901 line protective device on EHV (extra high voltage) level based on microcomputer which is made in NARI Company as the main simulation object. As the basic analysis tool for line protection, the software provides several analysis modules, including line pilot protection analysis, impedance protection using power frequency fault components analysis, distance protection analysis, zero sequence protection analysis and other various kinds of protection analysis units. It can be used to display the data process and the results, and also can replay the fault waveform and event data. When incorrect operation occurs, the software can analyze the cause, and analyze the sensitivity and safety margin when correct operation. It overcomes the flaws of the existing fault analysis software in analyzing the protection actions, and satisfies the analysis needs for the fault operating. The system is an effective tool in fault analysis, setting and protection algorithm evaluation.The paper elaborates the general design scheme and frame construction of the system at first, and then explains the fault data processing algorithm and protection analysis algorithm involved in detail. At last, the paper introduces the functions of the software briefly, and based on the actual recording data, carries out the simulation.The software is compiled in C++ language, using Microsoft Visual C++ as development tools, and passed debug in Windows XP.