Three-Phase Fault Analysis for a 28-Bus Distribution System

This MATLAB script performs three-phase fault analysis on a 28-bus distribution system. It calculates fault current and voltage magnitude.

This MATLAB code is designed to analyze the effects of a three-phase fault occurring at a randomly selected bus in a 28-bus radial power distribution system. The analysis is based on per-unit normalization with 15 kV and 20 MVA base values. Key features of the code include:

• Construction of the positive-sequence impedance matrix (Zbus) for the radial network.
• Calculation of total three-phase fault current at the faulted bus.
• Estimation of fault current contributions from all other buses.
• Determination of post-fault voltage magnitudes across the network.

The line data includes both positive and zero-sequence impedances, although this specific analysis focuses on three-phase (balanced) faults, making use of only the positive-sequence network. The script can be adapted for other fault types or extended to include protection coordination studies.