Power Quality Assessment and Analysis for Low Voltage Distribution Networks

Due to high application of non-linear loads and energy-saving devices at low voltage networks, power quality (PQ) assessment and investigation becomes an important requirement for electrical systems. Such a step is required to reveal the current situation of power quality, identify the margin from the unsafe boundary and take necessary remedial actions. The purpose of this paper is to investigate and assess the current situation of power quality of a low voltage distribution system within the Jordanian electrical system. The study was conducted for aggregated commercial and residential facilities. Several power quality parameters are monitored: Voltage distortion, current distortion, and power factor. Detailed measurement results and analysis are presented and explained. Among different power quality disturbances, load unbalance and distorted waveform of the current are observed. The results show that current unbalance reaches as high as 56% of the phase current. High total harmonic distortion (THD) level in the current is also observed. Its maximum value reaches 30.36%, while the Total Current Demand Distortion (TDD) level reaches as high as 10%.