THE ABSORPTION CHARACTERISTICS OF THE PHASE AND ZONE PAPER-IMPREGNATED INSULATION OF POWER CABLE AT DIRECT VOLTAGE
Journal Title: Електротехніка і Електромеханіка - Year 2015, Vol 0, Issue 5
Abstract
Introduction. The moral and physical deterioration of medium voltage power cables with phase and zone paper-impregnated insulation requires implementation of quality systems and reliable nondestructive electric diagnostic. Informative indicator of the insulation is the time decay curve of the charging current. It reflects the processes of accumulation of space charges (absorption). The measurements are carried out the 15th since the second direct voltage supply, then – on the 30th and the second on the 60th second. The ratio of the parameters measured in these times gives the dimensionless criteria – absorption coefficients. Three measurements are made at different times, provide a more complete picture of the state of insulation than the measurement of the value of steady leakage (conduction-through), adopted in conventional prevention trials. Purpose. Research and testing methods of diagnostics of power cables with paper-impregnated insulation by absorption and phase characteristics of the belt insulation based on the total measurements. Methodology. A procedure for determining the individual characteristics of phase and zone paper-impregnated insulation based realized on the use of the equivalent circuit of a three-core cable in the metal shell and solved of an over determined system of linear algebraic equations by least squares. Results. The proposed method allows determining the absorption characteristics of the individual phase and zone insulation medium voltage power cables in the overall metal shell at a direct voltage. Individual characteristics reflect the characteristics of cables and allow a greater degree to assess the degree of aging of each of the components of paper-impregnated insulation. Originality. Regardless of the cable connection diagrams probing electric field grabs as the phase, and zone insulation. The cumulative nature of the measurement leads to the fact that the differences in the properties of insulation components are smoothed: the aggregate results of the measurements do not differ for the different schemes of the same type. The individual characteristics of isolation, defined on the basis of the proposed method are more differences than total, indicating that non-symmetrical modes of operation of the cable. Practical value. The values of individual characteristics power cables 6 kV are 3 times more total, because of what their direct measurement may be a problem. The total resistance of several insulation spaces connected in parallel, behind the individual. Smaller values of insulation resistance are measured more easily, especially on short samples cables.
Authors and Affiliations
G. V. Bezprozvannych, E. S. Moskvitin, A. G. Kyessaeyv
Keywords
Related Articles
- EP ID EP298271
- DOI 10.20998/2074-272X.2015.5.09
- Views 93
- Downloads 0
DIGITAL SUBSTATION COMPONENT SYSTEM "SMART GRID"
New production technologies of modern control systems have moved from the stage of research and experimentation into the stage of practical use. Modern communication standards for the exchange of information are develope...
AN ANTHOLOGY OF THE DISTINGUISHED ACHIEVEMENTS IN SCIENCE AND TECHNIQUE. PART 37: NOBEL PRIZE LAUREATES IN PHYSICS FOR 2000-2004
Purpose. Implementation of brief analytical review of the distinguished scientific achievements of the world scientists-physicists, awarded the Nobel bonus on physics for period 2000-2004. Methodology. Scientific methods...
DETERMINATION OF ECONOMICALLY JUSTIFIED PARAMETERS OF SYNCHRONOUS DISCONNECTION AT LOW-VOLTAGE CIRCUIT SWITCHING VIA A SYNCHRONOUS VACUUM CONTACTOR
Dependence of a single switching procedure cost upon the contact opening delay time and delay-time spread is derived for a low-voltage synchronous vacuum contactor. For different cost levels, boundaries of permissible va...
CORRELATION BETWEEN ELECTRICAL AND MECHANICAL CHARACTERISTICS OF CABLES WITH RADIATION-MODIFIED INSULATION ON THE BASIS OF A HALOGEN-FREE POLYMER COMPOSITION
Introduction. The high saturation of the cable routes of nuclear and thermal stations, wind parks and solar power plants, on-board systems imposes stringent requirements in the field of fire safety of cables, which makes...
THE DIAGNOSTICS OF INDUCTION MOTORS ROTOR BAR BREAKS BASED ON THE ANALYSIS OF ELECTROMOTIVE FORCE IN THE STATOR WINDINGS
A method for diagnostics of the induction motor rotor bar breaks, based on the wavelet-analysis of the electromotive force induced in the stator windings in the rundown mode is developed. A method for decomposition of th...