The Research Of Two-Terminal Fault Location And Virtual Protection Based On Fault Record Data

Along with Voltage Class become higher and higher, transportation distance become longer and longer, varied topography of transmission line through in modern Power System, transmission line occurred short-circuit fault easily. In particular, many terrains are mountains and wilderness or encountered bad weather, the line fault occurred frequently. When transmission line occurred short-circuit fault, whether can we accurate calculation of fault distance, and this determine that we find fault quickly and then remove it. It can minimize the risk of economic loss and power system oscillation if we can deal with the fault as soon as possible. Beside, through of study on virtual protection, we judge protective action is correct or wrong. If the protection device malfunction or delay action, we must repair or replace protective devices timely to prevent the recurrence of such fault action.This article mainly calculated fault distance accurately and evaluate the protection based on record data which fault wave recording device records. And then I am using java to programming series of algorithms and criteria. Finally software system has been finished. The software is realized to offline data analysis and put the data into waveform. Then the wave displayed on the screen in order to service for users of power system more convenient.First, this article proposed algorithm of two-terminal fault location. The algorithm is based on fundamental phase voltage and current fundamental electrical quantities which through the fault record data calculation. Then it used voltage and current both before fault or after fault electrical quantities, combine with asynchronous angle to derived algorithm formula. Build model using MATLAB to obtain simulated data and the simulation results verified accuracy of fault location algorithm. Finally, software realized fault location accuracy.On the other hand, when line fault occurs, virtual protection evaluate of switch action after switching. This paper designs three main modules, including device parameters management module, fault record data reading and processing module and logic protection module. The basic line protection model includes current protection and distance protection. The line parameters, action time setting value and start current parameters need to set specific parameters. All this parameters put into device parameters management module. We first put measured value compare with setting value, and then obtained the results about judge.The analysis software has achieved two functions now. It mainly includes display and analysis of recorded wave data, virtual realization of protective action and fault location accurately. The display of Waveform data is in order to observe easy visually. Fault location accurately and virtual protection discrimination can help to deal with fault. All in all, we achieved the research on power system virtual protection based on fault recorder data and development of fault recorder data analysis software.