Mezhenkova M. Mathematical model of power station for analysing transients and estimation of the relay protection devices behaviour

Object of research - the processes occurring in block units of power stations at indignation, caused by short circuits. The purpose of research is increasing of reliability of work of electric system due to perfection of methods of the analysis of transients on power stations during both symmetrical and asymmetrical short circuits and specifications of behavior and parameters of operation of relay protection devices on the basis of calculation results by the developed model of power station. Theoretical researches are based on substantive provisions of the theory of stationary and transitive duties of the alternating current machines, on the theory of relay protection of power systems elements, on the numerical methods of the analysis and using the computer facilities. The developed mathematical model of the power station allows to receive instant values of regime parameters and their symmetric components in the established and transitive modes The equivalent circuits parameters of turbogenerators 100-800 МWt capacity with the limited number of equivalent contours on a rotor are received. On the basis of results of modeling the analysis of generators reserve protections behavior is carried out at the short circuits, the modes in which the specified protection appear disabled are revealed and ways of their improvement are offered. The method of definition of currents and voltages symmetric components in transitive modes for instant phase values and their harmonious components is developed. The results of work are implemented in Vuglegirska power plant, in scientific institute "Teploelectroproect", and handed to service of relay protection of the Donbass electropower system and to electrotechnical department "Donbassenergo" for implementation. The results of researches may be used in design and adjust organizations, in power systems, on heat and atomic power station for calculations of short circuit currents, for choice of the equipment and parameters of operation of relay protection devices.