ANALYSIS OF POWER QUALITY INDICATORS IN INDUSTRIAL POWER NETWORKS

The aim of this study is to conduct a comprehensive analysis of power quality (PQ) indicators in the electrical networks of industrial enterprises in Ukraine, taking into account statistical data up to 2022 and changes caused by the full-scale war. Special attention is given to power supply in the metallurgical, chemical, and machine-building sectors, where the largest deviations in PQ parameters are recorded. The methods. The study is based on a comparative analysis of power quality measurement results at Ukrainian industrial enterprises. It incorporates statistical data up to 2022, monitoring results from the wartime period of 2022–2023, as well as relevant standards such as DSTU EN 50160:2014, IEEE 519, and ENTSO-E requirements. The analysis focuses on key causes of PQ deviations: harmonics, flicker, voltage unbalance, and reactive power issues. Findings. Prior to the war, the most significant PQ violations were observed in welding and foundry shops of metallurgical plants (THD_U up to 12%, voltage unbalance up to 3.6%), harmonic distortion of the 6th–16th orders at chemical facilities, and localized reactive power issues in machine-building enterprises. During the war, the primary challenges shifted to deep voltage sags, frequency instability under generator supply, and low power factor (cosφ). Part of the industrial sector was shut down, temporarily reducing the overall harmonic levels. The originality lies in the first comprehensive generalization of wartime impact on PQ parameters in Ukrainian industry. The paper presents unique data on THD, flicker, and unbalance under crisis conditions. Practical implementation of the research is in substantiating the need to implement modern tools for improving power quality — including active filters, reactive power compensators, and PQ monitoring systems.