Applied the Software of MATLAB to Calculate the Balanced Three-Phase Fault Using Impedance Matrix

The key point of this article narrates the balanced three-phase fault occurs on a bus in power system that is been calculated from impedance matrix using MATLAB application software. Its purpose is to solve the problem of changing buses voltage and lines current. During the calculation, the impedance value of each device is only taken from the positive sequence impedance value. This paper is divided two parts - one for handwriting and other for computer program algorithm to narrate, the latter purpose is to facilitate the accuracy and effectiveness up so that avoid clerical errors caused by complicated steps of handwriting, it was been verified from practical cases. The manuscript algorithm and the execute steps of the computer program are simultaneously describe it in order to see the pros or cons. For clearly explain what these steps of calculation, these calculation steps of program were been shown on the bottom of paper. In order to promote interesting learning and shorten the time of calculation and design, this method has become a convenient and effective tool for the calculation of balanced failure in the field of power system.