Brought to you by the South Ural State University
Professor Anton Korzhov of the Polytechnic Institute Department at South Ural State University developed solutions for enhancing the reliability of cable lines. His project will allow for enhancing the operational reliability and safety of cable lines under conditions of development of urban electric networks.
The innovation developed under Project 5-100 is based on new methods of studying the operation of the existing 6(10) kW cable lines.
The optimization of their operation as per resource economy criterion as the main element of the complex is being researched. An array of operational and mode data is taken into account, as well as subsurface-and-meteorological and electromagnetic parameters, the human factor and the impact of the modes of the network with the accepted relay protection and automatic control settings.
“We came to see the necessity of such a development having talked to our colleagues from the urban electric networks since these networks are based namely on these 6(10) kW cable lines with impregnated-paper insulation. Their failure-free operation and timely troubleshooting guarantee a reliable power supply for customers. I have been working on this problem for over 12 years now,” says the professor.
During the operation, premature ruptures in the insulation of cables and sleeves are registered, especially of those operating for a long time. In order to reveal what causes it, the patterns of occurrence of faults and deterioration of the cable's insulation are needed to be developed and specified at the phase of operation. Electrical and thermal deterioration of insulation are the most well-researched at present.
Insufficient attention is paid to: the issues of impacts on insulation; parameters of partial discharges and corrosive processes in cable shielding; factors related to the accepted design and operational solutions; the role of personnel; repeated short-circuiting; high-voltage testing; and the magnetic component of cable electromagnetic field.
The developed method of collecting and analyzing retrospective information for predicting the occurrence of faults in cable lines, as well as the provided recommendations on prolongation of their service life and the required rate of renovation have found application in the urban networks of Chelyabinsk and Neftekamsk. A patent for invention was obtained for the resource-saving setup of relay protection devices and automatic controls.
“At present for this research I’m involving students interested in it, and I’m planning to keep developing this field of electrical-engineering materials science new to our university,” says Mr. Korzhov.
This field’s research objective comprises competencies of not only electrical engineers, but also of specialists in physics, chemistry, mechanics, material science and mathematics. Our task is to find the most accessible and simple, practical ways of diagnosing the condition of cable networks, for instance, those which will help collect and process the mode and operational parameters.
Eventually these methods may be used as supplementary to the already developed methods of nondestructive diagnostics. The mentioned innovations are relevant in the context of switching operations with regard to the technical condition and the necessity to assess the remaining operational life.