Power Quality Issues with Modern Appliances

Abstract

This master thesis investigates and analyzes the topic "Power quality problems with modern appliances." The investigation examines the power consumption patterns, power factor, and harmonic distortions found in a wide range of modern household lighting and devices, utilizing two power quality analyzers: Entes MPR-47SE and Unipower Unilyzer 900. Significant variations in power quality measures were observed in the experimental data, with an emphasis on the disruptive effect of harmonic distortions emitted by modern appliances such as LED bulbs and electronics; while the impact of a single appliance is marginal, the large-scale aggregation of these modern loads injects substantial cumulative harmonic distortions into the network. This collective behavior compromises the power quality and dependability of low-voltage distribution systems by overloading neutral conductors and causing premature thermal aging of distribution transformers. As a result, the study underlines the necessity to develop solutions for reducing harmonic distortions and improving power quality in residential settings. The findings reveal that while the widespread adoption of energy efficient appliances like LEDs and small electronics reduces overall consumption, it introduces severe current Total Harmonic Distortion (THD), particularly third and fifth odd harmonics, which can trigger neutral overloads, accelerate transformer degradation, and increase distribution network losses. Future research should focus on designing integrated, real-time adaptive filtering strategies through collaborative efforts among academia, industry, and regulatory bodies, with the goal of standardizing harmonic signatures and protecting grid reliability while aligning consumer device efficiency with network stability.