Lebedka S. Models and methods for evaluating and selecting options resonance and impedance earthed neutral cable networks 6-10 kV

Object of study: electromagnetic transients during earth fault in networks 6-10 kV with different modes of neutral. Objective: to determine the conditions of application and parameters of resistive and resonant neutral grounding in electrical networks 6-10 kV. Methods: the theory of electromagnetic field, theory of electric circuits, Gire numerical method for solving systems of ordinary differential equations, the method of phase coordinates, mathematical modeling of electromagnetic transients. Theoretical and practical results: developed software tools to analyze electromagnetic transients in electrical networks 6-10 kV for the closure phase on the ground including network configuration, neutral mode, the factors that reduce the effectiveness of the practical implementation of resonant neutral grounding, found reason failure relaying in networks with resistive neutral grounding proposed quantitative assessment to determine the area of low-and high-resistance neutral grounding resistive. Novelty: the computer simulation elements for three-phase power networks multiples applied Gire implicit method of the second order, were further developed mathematical models of electromagnetic transients in electrical networks 6-10 kV based on equations in phase coordinates, improved methods of numerical and experimental determination of the resonance parameters and neutral grounding resistor elements. Degree of implementation: results of the use of technical services of "Sumyoblenergo" (Sumy) and "Kharkivoblenergo" (Kharkiv) for the transient analysis for earth fault in networks 6-10 kV and the choice of limiting currents and surge. Area of application: electricity.