Research of Non-sinusoidal Voltage in Power Supply System of Metallurgical Enterprises

Non-ferrous metallurgy enterprises are large consumers of electrical energy. The specifics of non-ferrous metals production involve the use of significant non-linear loads (6-12 phase valve inverters, induction furnaces, welding machines, etc.). This is up to 60% of the total load on the enterprise. Therefore, an important and urgent problem is the study, analysis and calculation of the quality indicators of electrical energy consumed. Much attention that is being paid to the problem of quality of electrical energy (QE) in recent years is explained by a significant economic damage due to QE indicators deterioration. Improving the basic indicators is a part of the energy- and resource-saving policy, the role and importance of which is now increasing all the time as a part of the energy program in the whole community. Based on the comprehensive energy audit in a non-ferrous metallurgy enterprise, the authors investigated coefficients characterizing the voltage non-sinusoidality: ratio of n-th harmonic component of voltage (k(U(n)), %) and ratio of non-sinusoidal voltage (k(U), %). According to the obtained samples coefficients, the authors performed a rank analysis of the spectrum of the most powerful electrical energy consumers (noevaya caste) higher harmonic (HH) voltage and determined the correlation coefficients between k(U(n)), k(U) and fraction of the noevaya caste electrical energy consumers (W, %). In addition, the contribution made by consumers in non-sinusoidality voltage at the points of common coupling (PCC) with the system is defined. The obtained results are introduced into the process at the enterprises of non-ferrous metallurgy for the production of hard alloys and zinc.