On-line evaluation of voltage quality indexes for harmonic distortion, flicker and sequence components

This paper describes an on-line voltage quality monitoring system, which detects simultaneously the total harmonic distortion, instantaneous flicker sensation and unbalancing components, present in three-phase voltages. To test the proposed monitoring functions, a microcomputer based system was implemented, processing the data on-line at 2.4 kHz sampling rate per phase. Signals with known disturbing effects were used to validate the algorithms. Results obtained from monitoring the network secondary voltages, are also presented to demonstrate the application feasibility of the proposed monitoring system