Transneft (Russia)

The application of a discrete wavelet transform, in particular Daubechies wavelets, to improve the accuracy and sensitivity of a leak detection system in main pipeline transport of oil and petroleum products is discussed. This study opens up prospects for further development and adaptation of the presented methods for transmitting technological information by communication channels.

The article considers publicly available corpus of texts presented in the internet, characterises and considers the potential of corpus linguistics for analysing the development of scientific trends, discourse and changes in the field of terminology. A dataset based on a corpus of texts of scientific articles in a petroleum transport trade journal and the Google Books Corpus is presented. The dataset allows us to examine changes in term usage frequencies from 1940 to 2019.The results of analyses of term usage frequencies are presented, and a comparison is made between changes in the technology industry and the development of key vocabulary. The results show that studies made using data from corpuses of scientific and technical texts have good potential for understanding trends in technological development and the dynamics of change in industry and terminology.

The study focuses on an assessment of the power quality of electrical consumers of Mariinsk substation of the Transneft–Western Siberia JSC and Skovorodino OPS-21 of Transneft–East LLC in the power systems adjacent to the Trans-Siberian Railway and Baikal–Amur Mainline. The dynamics of bringing the power quality indices at the OPS-21 to the normalized values of the State Standard (GOST 32144-2013) when using SVC-20/20-10 at this station is shown. The design solutions of the Round Table “Low quality of electricity in 35-220 kV electrical networks supplying electrified railways and public consumers. Technologies for its normalization” were noted within the framework of the International Forum “Electrical Networks”, Moscow, November 22–25, 2022.

The power converter for solar photovoltaic is considered, which contains one input choke, two transistors, two diodes and two output capacitors. The phase shift of the switching transistors of such a converter provides a doubling of the ripple frequency of the input choke current. This is due to the relatively small mass and cost of the converter. The use of a solar battery as a primary source of electricity and a three-level output DC/AC converter together with a rechargeable battery as a load determine the tasks of control this power converter. It is necessary that the control system is capable of both stabilizing the output voltage and limiting the output current, and working in the mode of searching for the peak power point of the solar battery. In order to create a control algorithm, a mathematical model of power converter for solar photovoltaic has been developed. The obtained mathematical model allowed to develop a control algorithm for the power converter concerned. A prototype of a power converter with a switching frequency of transistors equals 25 kHz and with an output power of 20 kW has been tested. The results obtained during the development of the control algorithm and testing of the prototype of the PC will be useful both for engineers developing converter equipment and for software engineers developing control for pulse converters.

The 3D problem of elastic wave scattering by a crack in the form of a half-plane in an elastic medium is considered. It is noted that the previously published solutions do not fully cover the issues relevant to ultrasonic flaw detection, for example, detecting transverse cracks in welds. The proposed solution is made by the Wiener–Hopf technique. It is shown that scattered longitudinal and transverse waves can be generally written in closed form. Some features of the identification of the tip of transverse cracks are noted, including scattering features during sonication of cracks along their surface and the influence of critical angles.

The 3D problem of elastic wave scattering by a crack in the form of a half-plane in an elastic medium is considered. It is noted that the previously published solutions do not fully cover the issues relevant to ultrasonic flaw detection, for example, to detect transverse cracks in welds. The proposed solution is made by the Wiener–Hopf tecnique. It is shown that scattered longitudinal and transverse waves can be generally written in the closed form. Some features of the identification of the tip of transverse cracks are noted, including scattering features during sonication of cracks along their surface and the influence of critical angles.

The problem of reducing the active component of the stator current and the energy efficiency of an asynchronous electric drive while reducing the load is analyzed, the preferred criterion for optimizing the control system of a locomotive traction electric drive is determined, and a method for calculating the dependence of the stator-flux linkage on the stator current optimized by the criterion of the minimum stator current of an asynchronous motor is presented. Using to the above methodology, the optimal dependence of the flux linkage on the current for the AD917UHL1 traction engine used in Russian locomotives is calculated, an approximation of the calculated dependence is performed, efficiency graphs are given for conventional and energy-efficient electric drive control; with low loads and energy-efficient control, the efficiency of the engine increases by 12%.