A Novel Faulty Phase Identification Algorithm and Fast DQ Transform Technique for Voltage Sag Detection

Abstract

The disturbances created in AC transmission line power flow due to various faults and unavoidable natural circumstances have to be monitored carefully for uninterrupted power supply to the consumer and to avoid unacceptable situations. Voltage sag is one such unwanted disturbance occurring in the power system due to varying causes like lightning, loose connections, accidental short circuits, tree branches touching the line, birds hitting the line, etc., owing to non-recoverable damage to sensitive equipment in industries which also leads to financial losses. This paper proposes a new technique using DQ transform and integrator for fast voltage sag detection which is possible within [Formula: see text]th of a cycle and a new algorithm to identify the faulty phase. The authors are able to detect the voltage sag within the lowest time of 0.3[Formula: see text]ms for single-phase fault and 0.2[Formula: see text]ms for two-phase and three-phase faults. The simulation results for various types of power system faults with different point-on-waveform (POW) are presented using MATLAB/Simulink tool.