Single-phase ground short circuits in the 6–10 kV mains and electrical traumas in the coal mines

Abstract

Introduction. This article provides analysis of electrical traumas and single-phase ground short circuits (SPGSC) in the 6–10 kV electrical systems in the period from 1995 to 2018. It has been shown that reduction in the number of SPGSC will improve electrical safety at coal mines. Research aim is to determine the interrelation between the indicated factors based on the statistical data in the 6–10 kV mains of coal mines according to SPGSC minor and moderate electrical traumas. Methodology. Coal production, development of single-phase ground short circuit and changes in numbers of injuries in the period from 1995 to 2018 have been analyzed making it possible to vividly and qualitatively estimate the dynamics of changes in coal output, the number of SPGSC, electrical traumas and determine the interrelation between these parameters. The discovered interrelation between SPGSC and electrical traumas allows to handle the problem of improving the electrical safety more seriously by means of reducing the number of SPGSC. Results. This article shows the main reasons of single-phase ground short circuit incidence depending on time. The article shows the main ways to lower the amount of single-phase ground short circuit in the 6–10 kV electrical systems of coal mines. Summary. Significant reduction in the number of single-phase ground short circuit in the 6–10 kV electrical systems and, as a consequence, reduction of electrical traumas at coal mines can be achieved by means of effectively limiting switching overvoltage, overvoltage in the mode of single-phase ground short circuit, reaching high selectivity of protection from ground short circuit and improving the quality of electrical energy, and limiting the overloading of electrical equipment and cables.

An Analysis of the Statistics of Technological Disruptions in a Medium Voltage Cable Distribution Network

“…Подобная тенденция наблюдается во многих сетях среднего класса напряжения. Например, в [17] на основе статистических данных исследовалась аварийность сетей горнодобывающих предприятий. Авторы работы показывают распределение ОЗЗ по элементам системы электроснабжения.…”

“…С 2010 по 2018 г. количество ОЗЗ, связанных с повреждением КЛ и ВЛ, также превалирует (48,5 %). В качестве основных причин отключений авторы выделяют грозовые и коммутационные перенапряжения, старение изоляции, механическое воздействие, перенапряжения в режиме ОЗЗ, перегрузка и т. д. Из [17] можно сделать вывод о значительном увеличении числа ОЗЗ, обусловленных коммутационными перенапряжениями и перегрузками. Если же рассматривать КЛ, то наиболее частой причиной и уязвимым элементом КЛ является пробой изоляции кабельной разделки.…”