The article shows the results of non-destructive technological control of the defects number in the enamel insulated wire based on polyimide insulation. The application of statistical analysis of the control indicators measurement results with the help of a mathematical trend model for their use in insulation defects online control is considered. Recommendations for the practical use of the trend function parameters for processing the obtained measurement indicators are offered. The main parameters of the trend are run-in and the period of normal isolation during technological time. Theoretically shown and confirmed by measurements, the algorithm for quantitative assessment of the tendency of enamel insulation defects change for PEEIDH2-200 wire with two-layer polyimide insulation during the inline technological cycle. The algorithm allows for making technical decisions both in real time and remote analysis. Data on the sensitivity of this approach to technological changes are given.
The article presents the results of analysis of construction principles and functionality of systems used to monitor the condition of high-voltage power transformers. The main functions of modern monitoring systems used to diagnose the condition of electrical network equipment both in Ukraine and abroad were analysed. Based on the analysis it was found that the most characteristic functions of monitoring systems are the detection of rapidly developing defects and continuous control of parameters necessary to predict and assess the state of equipment. It is shown that efficiency of monitoring systems will be determined by both accuracy of measuring instruments and adequacy of prediction and diagnostic models used in the process of measurement results processing. Requirements to the equipment which observance allows providing effective and economically reasonable use of monitoring systems are considered. The typical architecture of modern monitoring systems is analysed, the basic elements of such systems are considered. Basic levels of information flow processing within the systems for monitoring the condition of power transformers have been considered. A detailed description and justification for using diagnostic parameters for monitoring the main components of power transformers such as dissolved gases analysis, partial discharges, current, voltage and power of transformers, oil temperature in different transformer locations, switching and atmospheric overvoltages, short-circuit currents, deformation of windings and others are presented. The output parameters returned by monitoring systems are given. The introduction of modern systems and technical means of monitoring the condition of high-voltage power transformers will reduce the risks of emergencies and, consequently, reduce the economic losses associated with the replacement of damaged transformers and under-release of electrical energy.
Currently, the development trends of global medium voltage cable networks are aimed at the introduction of cables with cross-linked polyethylene insulation. Such cables have a higher operating temperature, which allows to increase their throughput, and increased stability when working in conditions of overload and short circuits. It is possible to determine the allowable heat and electrical loads only if the heat balance is observed. Fundamentally important for solving the problems of heat balance is the significant dependence of thermal conductivity and heat capacity of polyethylene insulation on temperature. It is established that the capacity of the cable, determined by regulatory models and average environmental parameters, provides only preliminary information about its heating. For certain requirements and for innovative cable designs, a necessary condition for determining the load capacity in real stationary modes of operation is the use of the heat balance model. A system of mathematical equations is proposed, which due to the combination of structural and thermophysical parameters of the cable with the conditions of the external environment allows to determine the parameters of the stationary thermal regime of the cable at any load current.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.