This paper presents the analysis of power supply restoration time after failures occurring in power lines. It found that the power supply restoration time depends on several constituents, such as the time for obtaining information on failures, the time for information recognition, the time to repair failures, and the time for connection harmonization. All these constituents have been considered more specifically. The main constituents’ results values of the power supply restoration time were analyzed for the electrical networks of regional power supply company “Oreolenergo”, a branch of Interregional Distribution Grid Company (IDGC) of Center. The Delphi method was used for determining the time for obtaining information on failures as well as the time for information recognition. The method of mathematical statistics was used to determine the repair time. The determined power supply restoration time (5.28 h) is similar to statistical values of the examined power supply company (the deviation was equal to 9.9%). The technical means of electrical network automation capable of the reduction of the power supply restoration time have also been found. These means were classified according to the time intervals they shorten.

Development of smart grids for power supply to rural consumers assumes the creation of adaptive voltage regulation systems in 0.38 … 10 kV electrical networks as one of the directions. This paper considers a new approach to create an algorithm for controlling the technical means of regulation and voltage stabilization. The proposed adaptive voltage regulation system allows collecting and processing information on the actual voltage at the consumer inputs and automatically determine the voltage regulation coefficient. The developed mathematical model allows calculating the voltage regulation coefficient depending on the voltage at various points of the 0.38 kV electric network. In the paper there are also new methods of adaptive automatic voltage regulation in the 0.38 kV electrical networks and the requirements to the functional capabilities of this system. The article suggests technical solutions for the implementation of adaptive automatic voltage regulation system. The successful tests of experimental model of this system have been carried out.

The paper proposes the analysis of power supply system efficiency, including power supply reliability, power quality, and the quality of technological connections to power networks. In the paper, there is the interpretation of the power supply system efficiency, the main criterion of which is the minimization of operation expenses. The article lists the types of expenses, divided into stimulating and supporting. It is found that the regulation of stimulating expenses allows managing the power supply system efficiency, while supporting expenses provide the ability to fulfill the conditions of quality of services from power supply companies. The dependencies of expense constituents on the power supply outage time are shown. It allows developing stimulating mechanisms for power supply companies and consumers to improve the power supply reliability, power quality and the service quality of technological connections.

Sectionalizing 0.4 kV power transmission lines (PTL) improves power supply reliability and reduces electricity undersupply through the prevention of energy disconnection of consumers in the event of a short circuit in the power line behind the sectionalizing unit (SU). This research examines the impact of sectionalizing on power supply reliability and reviews the literature on sectionalizing unit allocation strategies in electrical networks. This paper describes the experience of the use of sectionalizing units with listing strengths and weaknesses of adopted technical solutions and describes the new structure of sectionalizing units. A new methodology is proposed, whereby there are two criteria for allocating SU in 0.4 kV power transmission lines. The first criterion is the sensitivity limits against single-phase short circuits used for calculating the maximum distance at which SU can be installed. The second criterion is power supply reliability improvement, evaluating the cost-effectiveness of installing sectionalizing equipment by reducing power supply outage time. The established methodology was put to the test on an actual electrical system (Mezenka village, Orel area, Russia), which demonstrated that the installation of a sectionalizing unit paid off.

   АКТУАЛЬНОСТЬ. Надёжность электроснабжения потребителей зависит от надёжности всех элементов системы электроснабжения, в том числе устройств релейной защиты и автоматики (РЗиА). Знание современных значений показателей надёжности различных устройств позволяет учитывать их при проектировании РЗиА, выбирая более надёжные устройства, выявлять недостатки средств РЗиА и выполнять работу по устранению.    ЦЕЛЬ. В связи с недостаточностью открытых данных о современных значениях показателей надежности устройств релейной защиты и автоматики (РЗиА) электрических сетей 10-110 кВ, актуальным является вопрос их определения на примере энергосистем различных регионов.    МЕТОДЫ. Авторами приведены и проанализированы официальные статистические данные по количеству аварийных отказов, ложных и правильных срабатываний устройств релейной защиты и автоматики в электросетевой организации – филиале ПАО «Россети Центр» – Орелэнерго» за 2013-2021 годы.    РЕЗУЛЬТАТЫ. В ходе исследования были определены численные значения следующих показателей надежности устройств релейной защиты и автоматики: поток отказов и частота излишних срабатываний. Устройства релейной защиты и автоматики, для которых были определены показатели надежности, применяются для реализации дуговой защиты, максимальной токовой защиты, автоматического повторного включения, дифференциальной защиты шин и трансформатора, поперечной направленной дифференциальной защиты, газовой защиты трансформатора, дифференциально-фазной защиты.    ЗАКЛЮЧЕНИЕ. Установлены значения потока отказов для разных типов реле и микропроцессорных устройств РЗиА, например, для электромеханического реле типа ДЗТ-11, используемого для реализации дифференциальной защиты трансформаторов с высшим напряжением 110 кВ, поток отказов составляет 0,2 год^-1/ТОО гит., а частота излишних срабатываний - 22,22 год^-1/ТОО шт. Сделаны выводы, о необходимости мероприятий по регулированию уставок и техническому обслуживанию устройств различных типов.