Real-time power quality signals monitoring system

The increasing of sensitive electrical equipment in our technologies is the biggest issues to power line system. The quality of electrical power supply becomes more concern to customers or electric users. Power quality signals will affect manufacturing process, failure of equipment and economic losses. This paper presents the development of power quality signals monitoring system using linear time-frequency distribution (TFD) which is spectrogram. The TFD is used to represent the signals in time-frequency representation (TFR) and is very appropriate to analyze power quality signals that have magnitude and frequency variations. Parameters of signal such as instantaneous of root means square (RMS) voltage, fundamental RMS voltage, total waveform distortion (TWD), total harmonic distortion (THD) and total non-harmonic distortion (TnHD) are estimated from the TFR to identify the signal characteristics. Standard power line measurements are also calculated from voltage and current such as RMS voltage and current, real power, apparent power, reactive power, frequency and power factor. The developed system also shows high accuracy monitoring system that presents very low absolute percentage error (APE) measurements and is suitable for power quality monitoring purpose.