Nebera O. Improvement of methods and tools for simulation electric power supply systems with motor load

The object of study: transients in the power supply systems voltage of 6-10 kV with motor load nodes. Objective: analysis of modes of power supply systems with a motor load by improving the methods and means of mathematical modeling in phase coordinates. Methods: fundamental positions of the theory of transients in electrical systems and electrical machines AC, namely the nodal method, implicit method of Euler-Cauchy, Newton's method, the phase coordinates method. The thesis is devoted to the development of mathematical models of electric power supply systems with motor load that allows to reproduce electromagnetic and electromechanical components of transients in three-phase circuits of arbitrary configuration. In the work current state of the problem, existing methods and tools for simulation of power supply systems were analyzed. Scientific novelty: first time a mathematical model of transients based on equations in phase coordinates for power supply systems with static elements and rotating electrical machines was developed. Methods of forming and solutions of differential equations in phase coordinates in relation to three-phase systems were improved, method for determining parameters of elements in phase coordinates was proposed, elements of inverse matrices inductance of rotating electric machines in an analytical form were received. First time the method of determining local frequency variations in the electrical systems which provides to increase speed and efficiency of measurement and diagnostic devices was proposed. Introduction: the results introduced in PAT "Ukrgidroproekt" (Kharkiv), NVP "Khartron-Incor" (Kharkiv), in the educational process of the Department of electric power transmission of the National Technical University "Kharkiv Polytechnic Institute". Scope of application: analysis and improvement of the operating modes of power supply systems.