Novosibirsk State Technical University (NSTI) continues to work on the creation of a system for determining the technical condition of overhead power lines — the system will allow a computer to automatically classify structures, reducing the time of express diagnostics to three minutes.
"Among the causes of accidents on overhead power lines (overhead lines), external factors are most often indicated: winds, tornadoes, ice loads. But not everything is as obvious as it seems. Any structure has its own frequencies — this is as important a characteristic of the structure as its mass, volume or rigidity. One of the reasons for such destruction is that there is a coincidence of frequencies of external influence and internal, natural frequencies. According to the current regulatory documentation, more than a dozen parameters must be monitored to monitor the condition of structures. Each such parameter implies a separate measuring device and up to several hours of operation. However, there is GOST 31937-2011, which allows you to expressly assess buildings and structures according to their dynamic parameters. We decided to transform and modify this rapid assessment method to analyze the condition of power transmission poles. This will make it possible to quickly detect defective overhead line supports," commented Alexey Kozhevnikov, Associate Professor of the Department of Aircraft Strength at NSTU-NETI.
Earlier, the NSTU Institute of Electric Power Engineering developed a special hardware complex for measuring the vibration frequencies of structures and, also designed and manufactured reduced experimental designs of typical overhead line supports that preserve all technological elements and characteristics of real power line supports. It is on them that a special technique for measuring natural oscillation frequencies is being developed: the correct arrangement of sensors, the need, and the type of external influence are being studied.
"We bring the developed system of technical condition control to an automated format of work: a computer without human participation, based on embedded algorithms, decides on the distribution of a structure into one or another group of technical conditions: serviceable, operable, limited operable. We have a lot of work to do on the collection of real experimental data and statistics, but I can say that this will allow for rapid diagnostics in just three minutes," the researcher shared.
To obtain information about the condition of the overhead line support, up to four sensors must be installed on the structure. The collected data are then transferred to a special application on a smartphone or computer. The user receives a complete report on the recorded natural oscillation frequencies in the form of graphs and indicators that allow assessment of the support condition.
This system is an analogue of three different complexes for evaluating internal vibrations simaltaneously, but the advantage lies in the ability to measure the frequencies of natural vibrations without external additional impact on the support structure. This will make it easier and faster to assess the actual technical condition of the structure. Based on the frequency of vibrations, we can conclude to which defect it is related. The ability to take measurements and analyze data on-site in real time is one of the key points when using this technique.
The main promising task is to create a standard that will allow you to have a more accurate understanding of which fluctuations are the norm and which are the deviation. To achieve this, experiments are carried out on different types of overhead line supports. Scientists will have to work out the methodology, further test on different types of construction, and analysis of the information received.
Currently, the researchers are continuing to develop the project, expanding the scope of the proven methodology to various types of structures, such as: reinforced concrete pillars for urban and railway transport networks and, supports for power transmission lines of low-voltage distribution networks, which are mainly used in rural areas and the private sector. Experimental models of three types of metal supports have already been prepared for research.
