Methodology of online assessment of technical state of transformer substation 35/6 (10) kV by express analysis coefficient

THE PURPOSE. The purpose of this study is to develop a methodology for determining the coefficient of express analysis of the main equipment of a 35/6 (10) kV transformer substation (TS) to assess its technical condition. A three-level structural complex has been developed for measuring and express-analysis of the technical state of TP. The technical condition of the main equipment of the TP is analyzed according to the selected diagnostic parameters.METHODS. The TP monitoring system makes it possible to assess the performance of its elements online. Express analysis provides remote monitoring, monitoring of the condition of the operating equipment and forecasting changes in the technical condition.RESULTS. The proposed method for determining the coefficient of express analysis allows online monitoring of changes in monitored parameters, reducing the recovery time of failed elements, and maintaining equipment in a working condition. CONCLUSION. The proposed solutions make it possible to move to the organization of maintenance and repair of the main power and electrical equipment of the transformer substation according to the actual state, as well as to improve the reliability and quality of the transmission of electrical energy to consumers.

METHODS OF EXPERIMENTAL RESEARCH JUSTIFICATION OF MINIMUM GEOMETRIC PARAMETERS OF GRAVEL BACKFILL IN THE OIL RECEIVER OF THE TRANSFORMER SUBSTATION

Transformer is one of the most fire-hazardous types of equipment at power substations. In case of emergency operation or damage to the integrity of the case they can cause a fire. Statistics on fires show that 50 % of fires in the energy sector are transformer equipment; as a rule, such fires are accompanied by an emergency spill of oil from the transformer and its ignition. Existing approaches to limiting the spread of fire during accidents at oil-filled transformer substations are insufficient and economically costly to minimize the consequences of burning transformer oil spills. At the same time, a number of design parameters have been identified that negatively affect the effectiveness of fire control. In particular, the Rules for Arrangement of Electrical Installations provide for the provision of electrical substations with oil receivers which is covered with gravel, and the latter is constantly polluted due to environmental influences which impairs its capacity and cooling capacity. The design and geometrical parameters of oil receivers with oil removal by oil drains defined in Rules for Arrangement of Electrical Installations can be a subject of scientific researches for their improvement. The purpose of this article is to determine the main provisions of the methodology of experimental studies to substantiate the minimum geometric parameters of gravel backfill in the oil receiver of the transformer substation. The ultimate goal of the study is to identify patterns of changes in the temperature of transformer oil from the parameters and characteristics of the oil pan, which should perform the function of a fire barrier and cooling the oil below the flash point. The essence of the method of experimental research is to identify patterns of reduction of the combustion temperature of transformer oil to a temperature below the flash point depending on the geometric parameters of the gravel backfill during oil draining into the emergency tank (oil tank). The developed technique allows to determine changes in the temperature of transformer oil from the geometric parameters of the oil pan, which should perform the function of a fire barrier and cooling the oil below the flash point.

Improvement of the technology of installation of «pillows» under the foundation of CTS 10 / 0.4 kV kiosk type

THE PURPOSE. To determine the number of reconstructed, newly installed and replaced 10 / 0.4 kV transformer substations, consider an improved technology for installing a "pillow" under the foundation of a kiosk-type 10 / 0.4 kV transformer substation and determine the time spent on its installation. METHODS. The article presents an analysis of data on the number of reconstructed, newly installed and replaced 10 / 0.4 kV transformer substations, an algorithm for installing an improved "pillow" under the foundation of a 10 / 0.4 kV kiosk-type transformer substation. RESULTS. In the course of the experiment on the installation of an improved "pillow" under the foundation of the CTS, the time of work was determined. The total time spent on the construction of an improved "pillow" under the foundation of a kiosk-type CTS was 580 minutes, which is just over 9.5 hours. Also the standardized time of work during the installation of an improved "pillow" under the foundation of a kiosk-type CTS Also, the standardized time for performing work during the installation of an improved "pillow" under the foundation of a kiosk- type package transformer substation has been proposed. CONCLUSIONS. The use of the data presented in the article on the number of reconstructed, newly installed and replaced 10 / 0.4 kV transformer substations will allow scientists and specialists to develop and propose new methods of reconstruction and construction technologies for various transformer substations, as well as determine the economic efficiency of new foundations for transformer substations. The technology of kiosk-type CTS foundation installation described in the article will allow not only to increase the operational characteristics of the CTS, but also ensure the fire safety of the installed equipment. The technical solution specified in the article can be used during the reconstruction and construction of a 10 / 0.4 kV kiosk-type package transformer substation. The proposed algorithm for mounting an improved "pillow" under the foundation of a kiosk-type package transformer substation is universal, since it can be used at a package transformer substation of various capacities.

Improvement of the technology of installation of «pillows» under the foundation of CTS 10 / 0.4 kV kiosk type

THE PURPOSE. To determine the number of reconstructed, newly installed and replaced 10 / 0.4 kV transformer substations, consider an improved technology for installing a "pillow" under the foundation of a kiosk-type 10 / 0.4 kV transformer substation and determine the time spent on its installation. METHODS. The article presents an analysis of data on the number of reconstructed, newly installed and replaced 10 / 0.4 kV transformer substations, an algorithm for installing an improved "pillow" under the foundation of a 10 / 0.4 kV kiosk-type transformer substation. RESULTS. In the course of the experiment on the installation of an improved "pillow" under the foundation of the CTS, the time of work was determined. The total time spent on the construction of an improved "pillow" under the foundation of a kiosk-type CTS was 580 minutes, which is just over 9.5 hours. Also the standardized time of work during the installation of an improved "pillow" under the foundation of a kiosk-type CTS Also, the standardized time for performing work during the installation of an improved "pillow" under the foundation of a kiosk- type package transformer substation has been proposed. CONCLUSIONS. The use of the data presented in the article on the number of reconstructed, newly installed and replaced 10 / 0.4 kV transformer substations will allow scientists and specialists to develop and propose new methods of reconstruction and construction technologies for various transformer substations, as well as determine the economic efficiency of new foundations for transformer substations. The technology of kiosk-type CTS foundation installation described in the article will allow not only to increase the operational characteristics of the CTS, but also ensure the fire safety of the installed equipment. The technical solution specified in the article can be used during the reconstruction and construction of a 10 / 0.4 kV kiosk-type package transformer substation. The proposed algorithm for mounting an improved "pillow" under the foundation of a kiosk-type package transformer substation is universal, since it can be used at a package transformer substation of various capacities.

Power quality issues: Power supply interruptions as key constraint to development in Ekiti State, Nigeria

The power quality issues in the world today are critical to the development of different nations. Prosperity of each nation depends on availability of constant power supply and the quality of supply of power is very important to the required developments in world in the past, the present and the future. Constant power supply is a major challenge in Africa particularly in Nigeria where the generated power is less than thirty percent of the required power. The metrics of power quality are voltage sag, flickers, spikes, harmonics, notching, transients and interruptions. This paper reviewed power quality issues and the interruptions as they affect the development of the State. The level of interruptions in Ekiti State was thoroughly examined and the causes of power interruption in the State were investigated. The method used was the collection of data in respect of power interruptions on Ekiti feeders from the Benin distribution company, assessment of the collected data through simple programming as a command for plotting the graphs through the use of MATLAB 2015 depicting the behavioural pattern of the interruption for a period of six months in 2016. The result shows that the interrelationship between the interruptions and development particularly as it affects domestic consumers, small and medium scale enterprise adversely. Recommendations were suggested with the objective of solving the problems being set up by interruptions in the State and these include installation of reactors, automatic voltage regulators and effective tap changing system on the lines, busses and transformer substation respectively.