ANALYSIS OF POWER SUPPLY QUALITY ISSUES IN MODERN ELECTRICAL SYSTEMS

Abstract

This paper considers the urgency of the problem of ensuring the quality of electric power (EP) in modern power supply systems (PSS), which is associated with the growing integration of distributed generation (DG) and the widespread use of nonlinear loads. The key challenges caused by the distortion of voltage and current sinusoidality by higher harmonics, as well as difficulties in managing reactive power and maintaining voltage stability are analyzed. The purpose of the article is to comprehensively analyze the problems of harmonic distortion and reactive power control in a PPS with DG, as well as to demonstrate the scale of these problems based on experimental studies of NP parameters at a real industrial facility. The research methodology includes an analysis of scientific and technical literature and regulatory documents governing power quality indicators. Experimental measurements were made at a complete transformer substation (CTS) of the rolling mill of an industrial enterprise using a specialized power quality analyzer. Time trends of voltage, current, power factor, total harmonic distortion coefficients of voltage (THDU) and current (THDI), as well as the spectral composition of harmonics were analyzed. The study found that the operation of a powerful nonlinear load (rolling mill) leads to significant distortions of NF. A significant excess of the standard values of THDU (average values of 12–13 %, peak values of more than 20 %) and THDI (average values of 45–90 %, peak values of more than 100 %) was recorded. The scientific novelty lies in obtaining and analyzing relevant experimental data on the levels of harmonic distortion generated by modern powerful industrial equipment and their complex impact on the NP indicators in a real EPS, which complements existing theoretical studies and models. The practical value of the results obtained is to substantiate the limitations of the use of standard means of reactive power compensation at high harmonic levels and to provide recommendations on the need to use active filters or static reactive power generation devices to effectively improve the EE at similar industrial facilities, which will help to increase the reliability and energy efficiency of their power supply.