Development Of Visual Relay Setting Calculation Software Of Large-capacity Generators

Currently, most electricity production and design departments still use manual or semi-manual method in calculation of relay protective setting. It always has a long cycle with low efficiency. Furthermore, it is vulnerable to errors caused by human factors. With the rapid development of computer technology, computer technology and software systems have been widely applied to various fields. Today computer-based relay protection solutions have developed rapidly. Compared to the normal method, developing computer software can solve complex computational problems of relay protection settings with greater accuracy and speed.Microsoft Visio has a powerful graphical modeling capabilities and data exchange control environment, besides, it will support secondary development of programming language. Compared with traditional graphical secondary development platform such as AutoCAD, Visio provides a more complex interactive design, flexible and efficient graphics operation function, which can improve system performance and applicability. This paper adopted Microsoft Visio as graphical development platform to do secondary development work combining with expertise in power system. It combined the drawing function of first system wiring diagram of power station with calculation function of power system, which formed the software with parameters input, status setting and results output function based on system wiring diagram of power station. It was called as visual or graphical relay protection setting calculation software. The main content of this paper is as follows:1. It completed an independent module of system short-circuit calculation where the short-circuit point is user-defined. It completed the appropriate modules for topological analysis of first system, which included node automatic numbering module, node admittance matrix forming module and matrix inversion module.2. The paper achieved relay setting calculation and completed the relay setting calculation module. Through the development of new command on the menu bar, relay protection setting calculation results show directly. This module can calculate the short circuit automatically and store the results for relay protection setting calculation.3. It used the software to test the short-circuit calculation and setting calculation of first-stage project of a power plant. The paper compared the output data with the data calculated by hand to test whether the software met the design requirements. In summary, the software had strong practicability, good universality and expansibility. It can realize the automated and intelligent computing which is easy for setting calculation personnel to use and manage. What is more, the Visio secondary development used in this paper also provided new effective ways for study of other application software on power system.