АНАЛІЗ ЕЛЕКТРОМАГНІТНИХ ПЕРЕХІДНИХ ПРОЦЕСІВ В ПРОМИСЛОВІЙ НИЗЬКОВОЛЬТНІЙ РОЗПОДІЛЬЧІЙ МЕРЕЖІ З АСИНХРОННИМ НАВАНТАЖЕННЯМ

Abstract

The article is devoted to the issue of short-circuit analysis in the low-voltage network of the power supply system of an industrial enterprise. The analysis methodology is based on the recommendations of the IEC 60909 standard and the ANSI/IEEE C37 series standard, which regulate the calculation of short-circuit current for the selection and verification of switchgear and protective devices according to the level of short-circuit current. The Electrical Transient Analyzer Program (ETAP) software was used as an analysis tool. Short-circuit analysis is performed in two stages: the first stages involves modelling the low-voltage distribution network of the industrial facility; the second stages involves the simulation of faults in the network. The modelling the low-voltage distribution network takes into account the features of the network configuration with inductions motors used in the technological process. The Short Circuit module of the ETAP software was used to calculate the short-circuit current on the bus of the distribution network. The performed analysis takes into account the induction motors contribution to the level of short-circuit current. The result of the analysis is the determination of symmetrical and asymmetrical short-circuit current values and the detection of inconsistency of the characteristics of the installed equipment with short-circuit currents. Analysis of short-circuit current using ETAP software provides the possibility of selecting switchgear and protective devices according to the level of short-circuit current and verify the correctness of the decisions made regarding the selection of low-voltage switchgear of the distribution network, which contributes to the design of a reliable power supply system for the facility.