Development of a methodology for calculating swings in an electrical system

Introduction. The most dangerous type of accident in an electrical system is short circuits, which lead to damage to equipment, increased wear on overhead insulation, and loss of electricity. After disconnecting short circuits with the help of relay protection, swings occur in the system, the nature of which is determined by the previous emergency and subsequent post-emergency mode of the system. The purpose of the research: determination of the maximum and maximum permissible angles of divergence of the EMF of the generator, the system and the swing currents in the line under the condition of dynamic stability. Objects and methods. The object of the study is the high–pressure hydroelectric power plant (HPP) of PJSC RusHydro - Zaramagskaya HPP. The main methods used to solve the tasks set in the work are methods for analyzing electromechanical transients based on the use of systems of differential equations. Results and discussions. The paper proposes a method for calculating the oscillating currents in an electrical system, which provides for determining the maximum and maximum angles of divergence of the EMF of the generator, the system and the oscillating currents in the line, which are permissible under the condition of dynamic stability. Conclusion. The described methodology allows calculating the maximum swing current in the line in the post-emergency mode, which prevents the occurrence of emergency modes in the electrical system. It should be emphasized that improper operation of the protection against swing currents can lead to the most severe type of system failure – a complete loss of communication between the generator and the system. Prospects for further research. Based on existing methods for analyzing electromechanical transients based on the use of systems of differential equations, the developed method for calculating swing currents in an electrical system can be used in the analysis of similar objects involving communication between the system and the generator under various operating conditions. Keywords: electrical system, swing currents, post-emergency modes, absolute acceleration of the generator, angle of divergence of the electromotive force, dynamic stability.