19 февраля 2018
«ЭЛЕКТРОЭНЕРГИЯ. Передача и распределение» № 1(46), январь-февраль 2018
СЕТИ 20 КВ
ДИАГНОСТИКА И МОНИТОРИНГ
ДИАГНОСТИКА И МОНИТОРИНГ
ПУТЕШЕСТВИЕ В ПРОШЛОЕ
The paper considers required measures for implementing voltage balancing and reactive power compensation in external power supply systems of electric railway.
power supply of railways, asymmetric loads, voltage balancing, power quality
The paper considers problems with overhead transmission lines gust-and-glaze loading in IDGC of South, PJSC electrical networks during autumn and winter period. Intelligent ice-melting system for overhead conductors and lightning protection cables based on universal ice melting equipment is proposed. Comparison of the system with generally accepted methods and installations is carried out. Efficiency of the system for application on 35 and 110 kV overhead lines of “Rostovenergo” (Branch of IDGC of South, PJSC) is demonstrated.
:glaze formation, ice melting, innovation, system for forecasting, early detecting and control of ice formation, intelligent ice melting system, extension cord, technical-and-economic efficiency
. Already more than 10–15 years in all classes of rated voltages from 6 kV and higher in Russia and in the world are being widely used single-core cables with XLPE insulation. Unfortunately, the normative documents and cable instructions still did not have easy methods to calculate longitudinal cable parameters that would allow to determine the series active and inductive impedance for direct and zero sequence depending on the cable sheath grounding scheme. The article offers the simple method.
cable line, single-phase cable, cross-linked polyethylene, the longitudinal impedance of the line, direct sequence, zero sequence, sheath grounding
. The possibility of energy bridges construction using superconducting technologies based on previously obtained experimental and theoretical results is shown. Power transmission capacity, total length of the line, maximum distance between the cryogenic stations, as well as the energy losses and required power of the cryogenic station are estimated. It is demonstrated that creation of superconducting transmission lines with power about 10 GW and any length is possible taking into account current level of superconducting and cryogenic technology development. It is shown that cryogenic stations should be placed along the transmission line with a maximum step of 45-75 km. The possibility of increasing the distance between cryogenic stations by improving the cryostats thermal isolation is discussed.
high-temperature superconductivity, superconducting and cryogenic technology, cryogenic equipment, long-distance cable lines
The main element of the modern current-limiting device designed to operate on the line voltage up to 110 KV, is a fast-blast switch, which is composed of various explosives. The explosive switch to standby mode is exposed to different physical and chemical parameters. The results of experimental studies of the influence of the operating parameters (temperature, vibration, thermolysis) are shown in the work. The methodology and results of the evaluation of physical and chemical resistance of different types of explosives used in blasting fast switches are presented.
current-limiting device, explosive commutator, physical and chemical resistance, thermolysis