Научная статья на тему 'The magnetic field of a multi-phase induction device with switching windings from a triangle to a star'

The magnetic field of a multi-phase induction device with switching windings from a triangle to a star Текст научной статьи по специальности «Электротехника, электронная техника, информационные технологии»

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Ключевые слова
INDUCTOR OF LONGITUDINAL MAGNETIC FIELD / THREE-PHASE INDUCTION DEVICE / SWITCHING THE TRIANGLE OF WINDINGS INTO A STAR / VECTOR DIAGRAM OF MAGNETIC FLUXES / NONLINEAR MULTIPHASE MODEL OF A MAGNETIC CIRCUIT / ASYMMETRY OF THE THREE-PHASE FREQUENCY INVERTER MODE

Аннотация научной статьи по электротехнике, электронной технике, информационным технологиям, автор научной работы — Tyapin A., Kinev E.

The peculiarities of the configuration of the magnetic field of an induction device designed to influence the molten metal are considered. The windings of the induction machine are made switchable, from a triangle into a star, which ensures the operation of the device when pumping, transporting, or mixing aluminum alloys. Heating the melt with a field is able to ensure the removal of aluminum plugs at the start, as well as to compensate for heat losses during casting. The device is one of the varieties of linear MHD machines with a core and windings, with a variable number of pole pairs. The sequence of switching windings is determined by the algorithm of the control unit modules. Due to the open configuration of the magnetic circuit of the MHD inductor, asymmetry of the magnetomotive forces of the windings occurs, which leads to a distortion of the low-frequency traveling magnetic field. The nature of the asymmetry of the electromagnetic mode of the shortened inductors for different winding switching circuits can be estimated from the model of the magnetic circuit. The distribution of magnetic flux vectors is estimated from the results of an iterative calculation of a nonlinear multiphase magnetic circuit of an induction machine. For the scheme of separate switching on the phases of the inductor, there is a software-algorithmic method for controlling the power switches of a three-phase IGBT inverter operating at lower frequencies. Regulation of the force and intensity of heating is performed by redistributing by the linear current load between the phases of the inductor. With the proper choice of the winding connection scheme, the proposed device provides a continuous circular raster of flows in the cores, creating uniform traction forces and increasing the effect on the melt.

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Текст научной работы на тему «The magnetic field of a multi-phase induction device with switching windings from a triangle to a star»

3. Кукуи Ф.Д., Скороходов Д.А. К вопросу об обеспечении безопасности судна судоводителем // Наука и транспорт. №2. Москва 2012. С. 30 - 33.

4. Международная конвенция о подготовке и дипломировании моряков и несении вахты 1978/95 года (ПДМНВ-78/95) с поправками.

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6. Организационно-технические структуры, обеспечивающие безопасную эксплуатацию судна / М. А. Гладышевский, М. А. Пасечников, К. В. Пеньковская ; под общ. ред. В. И. Меньшикова. Мурманск : Изд-во МГТУ, 2008. 212 с.

7. Основные процессы в структурах безопасной эксплуатации судна / Ф. Д. Кукуи, Н. А. Ани-симов, А.А. Анисимов; под общ ред В. И. Меньшикова. Мурманск : Изд-во МГТУ, 2008. 185с.

8. Проблемы безопасного мореплавания в сложных навигационных условиях стесненных вод / В. И. Меньшиков, А. Н. Суслов, В. В. Шутов; под общ. ред. В. И. Меньшикова. Мурманск: Изд-во МГТУ, 2013.186 с.

9. Резолюция ИМО А.772 (18) «Фактор усталости при укомплектовании судов экипажами и обеспечении безопасности» от 04 ноября 1993 г.

10. Резолюция ИМО А.947 (23) «Принципы и цели организации в отношении концепции человеческого элемента» от 05 ноября 2003 г.

THE MAGNETIC FIELD OF A MULTI-PHASE INDUCTION DEVICE WITH SWITCHING WINDINGS FROM A TRIANGLE TO A STAR

Tyapin A.,

Postgraduate student, Siberian Federal University

Kinev E.

Candidate of technical sciences, Director Thermal Electric Systems LLC

Abstract

The peculiarities of the configuration of the magnetic field of an induction device designed to influence the molten metal are considered. The windings of the induction machine are made switchable, from a triangle into a star, which ensures the operation of the device when pumping, transporting, or mixing aluminum alloys. Heating the melt with a field is able to ensure the removal of aluminum plugs at the start, as well as to compensate for heat losses during casting. The device is one of the varieties of linear MHD machines with a core and windings, with a variable number of pole pairs. The sequence of switching windings is determined by the algorithm of the control unit modules. Due to the open configuration of the magnetic circuit of the MHD inductor, asymmetry of the magnetomotive forces of the windings occurs, which leads to a distortion of the low-frequency traveling magnetic field. The nature of the asymmetry of the electromagnetic mode of the shortened inductors for different winding switching circuits can be estimated from the model of the magnetic circuit. The distribution of magnetic flux vectors is estimated from the results of an iterative calculation of a nonlinear multiphase magnetic circuit of an induction machine. For the scheme of separate switching on the phases of the inductor, there is a software-algorithmic method for controlling the power switches of a three-phase IGBT inverter operating at lower frequencies. Regulation of the force and intensity of heating is performed by redistributing by the linear current load between the phases of the inductor. With the proper choice of the winding connection scheme, the proposed device provides a continuous circular raster of flows in the cores, creating uniform traction forces and increasing the effect on the melt.

Keywords: inductor of longitudinal magnetic field; three-phase induction device; switching the triangle of windings into a star; vector diagram of magnetic fluxes; nonlinear multiphase model of a magnetic circuit; asymmetry of the three-phase frequency inverter mode.

Most industrial induction devices are designed for use in three-phase shop electrical distribution networks. This is due to the advantages of a three-phase system in the transmission of increased power, compared to a single-phase one. But there is another advantage in the industrial power supply, which is the possibility of power supply of induction equipment, both on the phase and on the line voltage. In addition to the magnitude of the supply voltages, their space-time orientation is essential. With regard to devices with windings, this is convenient, since it allows you to control the internal magnetic field. For the common schemes of connecting three-phase windings with a star and a triangle, it is possible to perform a mutual switching procedure for a radical change in the characteristics of the equipment. In electric machines, such switching leads to changes in

the number of poles and the frequency of rotation of the motors. This effect can be successfully used to create linear induction machines for metallurgical purposes.

Many relatively old [1-3, 10, 15] and new publications [4, 5, 8, 9, 11, 12, 14-17] are devoted to the development of induction machines. The literature shows that transverse and longitudinal magnetic field inductors have found application in magnetohydrodynamic stirrers, pumps, and gates for the force effect on an aluminum melt during its transportation from a furnace or dosing. In addition to the force effect on the melt, induction machines provide thermal effects and can be used to heat aluminum when it is pumped between tanks.

A dosing device for a liquid metal containing a ceramic pipe located between the poles of an inductor

running magnetic field was proposed in [1, p.2]. This device provides for the possibility of melting the "plug" of the frozen metal at the beginning of casting and its formation at the end of casting. This approach provides overlap of the pipe in the interval between the casting of molten metal, as well as the possibility of automating the process. However, the application of the proposed device, it is difficult to normalize the release in the molten metal the amount of heat that may be excessive.

In a similar device for pumping a liquid metal, proposed in [2, 3], the melt is driven by electromagnetic forces of a traveling magnetic field. The running electromagnetic field induces induced currents in the liquid metal, the interaction of which with the inductor field creates electromagnetic forces. The electromagnetic inductor creates pressure in the melt, which ensures the lifting of the metal to a certain height in order to overcome the hydraulic resistance of the liquid metal. Simultaneously with the mechanical force, the induced currents cause the release of heat in the liquid metal. It can be used to prevent metal from cooling.

The disadvantage of this method of moving a liquid metal is that the heat released in the liquid metal, while creating the required amount of hydraulic head, may be excessive. This can lead to overheating of the metal, violation of the technological process of preparation of the alloy. Another risk is the lack of heat and solidification of the metal before moving or mixing [4, p.3].

In addition to the listed induction devices, electric motors are known that have two or more rotational speeds. By changing the stator winding circuit, you can change the number of poles and get different speeds when powered from a source of constant frequency. By switching the windings and changing the direction of the current in the coil group or phase, they get twice the number of poles. Such regulation is convenient to use in induction machines.

Formulation of the problem. The effect of an electromagnetic field on metal melts seems to be a universal way to control casting. Considering the simplicity and efficiency of electromagnetic inductors of a longitudinal magnetic field, it is necessary to develop an

MHD device suitable for pumping, metering and mixing molten aluminum. The creation of an induction device should provide simple winding switching controls for the most common triangle or star insertion schemes. In the power supply system of an induction device, a three-phase low-frequency IGBT inverter can be used, capable of stably operating at the edge of the frequency range, with a high asymmetry of currents in phases.

Decision. The above technical devices provide the ability to control the electromagnetic pressure developed by the electromagnetic pump, built on the basis of a longitudinal magnetic field inductor [5, p.65]. The effect of controlling the casting of metal can be obtained by switching the connection "double star" - "single triangle". Regulation of the regime is achieved by using a combined circuit of switching on windings with controlled keys and using a three-phase frequency converter [6, p.57].

The proposed induction device acts on non-ferrous metals, therefore, using three-phase inverters in the windings, they create low-frequency currents, increasing the penetration depth of the electromagnetic wave. The fixed values of the frequency of currents in MHD machines are significantly different. For dispensers, the frequency values are chosen higher, for electromagnetic trays the current frequency is optimized in the range of 5-15 Hz, for stirrers the range is 0.5-1.5 Hz [7, p.27]. By varying the voltage, it is possible to control the linear current load by changing the electromagnetic pressure [8 - 10]. At the same time, the power released in the liquid metal is also regulated.

The section of the induction MHD device placed in the wall of the furnace is shown in fig. 1, a. Inductor 1 for pumping high-temperature melt is installed in the space of the wall of the stationary furnace through the flanges 2 inside the cast iron plate 3. At the end of the tray there is a section 4 for transporting the melt from the furnace to the casting machine. To protect the inductor from molten aluminum, lining is used [10, 11]. It consists of a rear cinder stone 5, a heat-insulating tube 6 and a front cage stone 7. The inductor of the MHD device is connected to the inverter through a switching unit (SU).

Fig. 1. Section of a compact MHD device

The work of the MHD machine, is as follows. Dosing melt is pumped through the insulating tube 6 through the channel. Alternating current of adjustable frequency in the windings of inductor 1 creates a run-

ning magnetic field in the heat-insulating tube 6. Induced eddy currents in the liquid metal, lead to the appearance of electromagnetic pressure. Depending on the direction of the traveling magnetic field, the pressure either counteracts the outflow of the melt from the

b

a

stationary furnace, or vice versa, contributes to the creation of the flow. Thus, the electromagnetic force of the inductor either reduces the flow rate of the melt, or accelerates it. Inductor 1 (Fig. 1, b) is made with a winding 8, assembled from six disk sections (six-zone winding) and located between steel cores 9, fixed inside the pipe 10 of the magnetic core. Inside the MHD device is a non-magnetic steel pipe with slit 11.

An example of one of the induction machine switching schemes is shown in fig. 2. The inductor of

the MHD device has six coil groups w1, w2, w3, w4, ws, w6 (fig. 1, b) which are designated by numbers 1 ^ 6 (fig. 2). A modified image of the same device is shown in Fig. 3 According to the presented scheme, the induction machine coils are connected to a triangle or a star through a switching unit (BC) implemented on the controlled keys sn, s21, s31, s12, s22, s32, s13, s23, s33. Both in the initial (Fig. 2) and in the modified scheme (Fig. 3) three switching options are implemented. The scheme of the triangle (Fig. 2) is quite obvious.

Fig. 2. The switching circuit of the MHD device when connecting by a triangle

By switching the windings of the same inductor, you can get a connection to a double star, as well as a single star with a reduced number of sections. For switching power supply circuits use electronic switches. The modified scheme (Fig. 3) for a triangle connection is implicit. However, the functionality of all elements of the scheme is preserved. The input voltage of the shop distribution network is initially designated by the letters A, B, C. The sections of the inductor w are numbered in the through sequence 1, 2, 3, 4, 5, 6 and arranged in order. The beginnings of all coil groups

are designated by the letters i1, i2, i3, i4, i5, i6 and marked with dots. The ends of the winding sections are designated by the letters o1, o2, o3, o4, o5, o6.

If necessary, in order to change the distribution of magnetic fluxes, an inversion can be introduced into the order of the alternation of contacts by performing the appropriate switching by jumper. The terminal contacts for the phase terminals of the frequency inverter (voltage regulator) are marked with the letters U, V, W and N.

Fig. 3. MHD device in a triangle based on the switching unit

The order of controlling the switching of keys sij can be represented by a set of logical states for which expressions are written in a matrix form. This is convenient for programming digital control systems. Below is a general view of the matrix of logical states of the key management system.

s11 s12 s13

[A] = s21 s22 S23

_S31 s32 s33

The on state of the key corresponds to the value of the logical unit, the off state corresponds to the logical zero. Assigning a logical zero to the elements of the matrix leads to the translation of the key sij to the disabled state and makes a change in the technological process.

At the beginning of casting in a stationary furnace, the level of the melt is maximum and it is necessary to counteract the hydrostatic pressure of the melt in the furnace due to the maximum pressure [13]. This pressure is provided for an inductor with the following parameters: the number of phases m = 3, the number of pole pairs 2p = 4, the number of winding groups Z = 6, the number of coils in the phase zone q = 1, the phase zone a = 120.

In the triangle connection scheme, a phase sequence UWVUWV (ACBACB) and pole step xi are provided, which is ensured by switching on the s11, s21, s3i switches and switching keys (si2, s22, s32, si3, s23, s33). The matrix of logical states in this case has the following form:

[Ai] =

The electrical circuit of the inclusion of a three-phase induction machine with six coil groups (Fig. 2), similar to the scheme of Fig. 3 provides switching windings from a triangle to a double star. In this case, the keys si2, s22, s32, si3, s23, s33 are enabled, and the keys su, s2i, s3i SU are disabled. In this case, the matrix of logical states of the key management system takes an inverse form:

S11 s12 s13 1 0 0

S21 s22 s23 = 1 0 0

S31 s32 s33 1 0 0

[A2] =

s11 s12 s13 0 1 1

s21 s22 s23 = 0 1 1

s31 s32 s33_ 0 1 1

Thus, a variant of the switching circuit of the windings of an induction MHD device is determined by the state of the electrical switches.

As the level of the melt decreases, the hydrostatic pressure of aluminum decreases [10, 13]. This requires a decrease in the head of the MHD pump, which can be weakened by decreasing the voltage of the power source. This decreases the current in the inductor coils and the linear load of current. In addition, the thermal power released in the liquid metal working body is reduced. The weakening of the action of the magnetic field of the inductor, accompanied by a decrease in the heating temperature. To maintain the required level of thermal power in the melt, at a certain moment, the MHD pump is switched to a circuit that forms other parameters of the inductor. The following combination is obtained: the number of phases m = 3, the number of pole pairs 2p = 2, the number of winding groups Z = 6, the number of coils in the phase zone q = 1, the phase zone a = 60.

The sequence of phase rotation UwVuWv (Az-BxCy) at the pole step X2 is provided by including the triac keys s^, s22, s32, s13, s23, s33 SU in a star and the disabled keys s11, s21, s31. In order to provide the necessary pressure, increase the linear current load [13 - 15], which leads to an increase in pressure. An increase in current is accompanied by an increase in the heat output in the liquid metal working body, which allows the melt to be heated to the required temperature.

The connection diagram of the inverter 3 to the induction machine 1 of the six-zone structure is shown in Fig. 4. In this embodiment, the number of combinations of the winding connection is large, so it is also advisable to use the switching unit 2, which, under the influence of the microcontroller, switches the windings from a star to a triangle or to a double star.

For a circuit in a triangle, with a similar AxYbCz connection to the transistor inverter, the equations are made according to Kirchhoffs laws:

% + h - h = 0 > h = h - h > /y + 4 + 4 = 0, 4 = -Ia- 4 > I\w - In - Ih = 0, 7w = h + Ih.

(2)

According to topological equations, the construction of vector diagrams of operating parameters is carried out and a set of requirements for an inverter is determined for characteristic cases of asymmetry. Modes are important when currents and voltages may be in antiphase, and the inverter will go into recovery mode [12].

Fig. 4. Connecting an inverter to a six-zone induction machine

An idealized vector diagram of voltages and currents of a six-zone MHD device with parameters m = 3, 2p = 4, Z = 6, q = 1, a = n / 3 and the sequence of alternating phases AYCAYC is shown in Fig. 5.

Fig. 5. Vector diagram of six-inductor currents

The phase shift 91 of the current of the first coil w1 is adopted inductive, for the characteristic, extremely low values of the power factor of the induction machine. The vectors of the coils wi, w3, w4, w6 are obtained by direct switching on the coil groups. Vectors w2, w5 are obtained by inversion of the inclusion of the corresponding winding. Using vector diagrams, one can get a general idea of the distribution of magnetic poles and the nature of the phase alternation in the windings of an induction machine. However, in a real device, the switching circuit of the six windings 8 located between the cores 9 (Fig. 1, b) may be different. Its configuration is determined by the nature of the distribution of magnetic fluxes and the resulting ratio of the components of the traveling and pulsating magnetic field in the inductor.

Due to the use of an open magnetic core and the presence of edge effects, the real picture of the distribution of currents and magnetic fluxes in an induction

machine differs significantly from the idealized symmetric one. To estimate the distribution of magnetic fluxes, it is necessary to create and analyze a mathematical model in the form of a system of equations of magnetic equilibrium [14, 17]. However, the analysis of such a system of equations is extremely difficult, since, in addition to edge effects, the mutual inductance of the windings should be taken into account with finite values of the magnetic permeability of the pipe and the inductor cores. The saturation of the steel in turn depends on the currents in the windings.

Practice has shown that in such conditions, the result is easier to obtain using circuit simulation mode, taking into account the listed features. A fragment of the spatial model of a nonlinear multiphase magnetic circuit, intended for the evaluation of integral fluxes, is shown in fig. 6.

Fig. 6. Fragment of a model of a nonlinear magnetic inductor circuit

The model uses controlled sources of magnetomotive forces as magnetizing sources, the mode of which is given by an equivalent sinusoid on the set of harmonics depending on the degree of steel saturation [17]. Moreover, the equivalent vectors of the magnetizing forces of the windings w2 and w5 of phase B, for a double star circuit, are inverted by an angle n to obtain a phase shift a = n/3, typical of the classical inclusion of windings with an inverted middle phase. The complexes of equivalent sinusoids of the magnetomotive forces of the phase W, are left unchanged, with the natural phase +2n/3 in direct sequence. Air gaps and metal melt in the model are represented by constant magnetic resistances, calculated from the actual geometry of the inductor, designed for small pumps with an air gap of 80-150 mm. The sections of the magnetic circuit are replaced by nonlinear resistances with a tabular description of magnetic weber-ampere characteristics.

The vector diagram of the magnetic fluxes in the cores of the induction machine, obtained from the six-

zone computational model, is shown in Fig. 7. The distribution of magnetic fluxes in the channel is shown in Fig. 8. On each diagram, a combination of flows with a system of magnetomotive winding forces is performed, in order to compare the obtained phase relations. The distribution of the magnetic field in the channel itself, directly in the region of the inducing coils, can be analyzed by another vector diagram (Fig. 8).

The obtained distribution of flows as a whole confirms the efficiency of the chosen scheme of the MHD device and its high tractive properties in such a configuration [17, p.345]. During the study, several winding switching circuits were tested, and for uniform distribution of phase shifts of magnetizing forces with an angle of n/3, the calculated values of the magnetic fluxes ®1 - ®7 turned out to be significantly less, and the nature of their distribution around the circumference turned out to be less uniform, which causes a greater influence of the components of the pulsating magnetic fields.

Fig. 7. Vector magnetic flux diagram of cores

Fig. 8. The distribution of magnetic vectors of the fluxe in the channel

The experience of using various connection circuits for induction machine windings allows us to recommend the most efficient winding connection configurations, among which the AYCAYC scheme has clear

advantages for small-sized products, especially for a double star. In such a compound, it is easy to realize the traditional inverse inclusion of the second phase, which creates phase shifts a (Fig. 5) for the magnetomotive

forces of a binary star. At the same time, better results and a more uniform distribution of flows teeth around the circumference with smaller values of the pulsating magnetic field components gives the condition F2 = F5 >> F1 = F4 and F2 = F5 >> F3 = F6. In practice, this means a greater number of turns in the middle windings of each star.

Another way to control the uniform distribution of magnetic flux is to control the frequency inverter mode [6, 11]. Judging by the vector diagram, it is the increase in the currents of the middle sections of the inductor (or the number of turns) affects the dynamics of the phase relationships of the fluxes in the cores of the induction MHD machine. Analysis of changes in phase shifts of magnetic fluxes ®1, ®2, ®3, ®4, ®5, ®6, ®7 according to the diagram (Fig. 7) is convenient to start from point M, counterclockwise. Folding the phase shifts 91-2, 923, 93-4, 94-5, 95-6, 96-7 in two incomplete turns, it is easy to confirm that the total angle of coverage of the melt in the channel approaches 700 degrees.

The vectors ®w1 and ®w4, ®w2 and ®w5, ®w3 and ®w6 turned out to be grouped in pairs, due to the same magnetizing forces of the windings of the same name and much larger. In this case, the phase shift 5 between closely located vectors of the same name is not the same. In addition, the vectors for magnetic fluxes in the extreme inducer coils are shifted closer to the center due to the presence of edge effects. The calculation showed a more than threefold increase in the intensity of the magnetic field of each coil in the channel, and given the proximity of adjacent vectors, the increase turns out to be almost sixfold.

The results of the calculation of currents and magnetic fluxes (Fig. 7, 8) for the steady state of a multiphase nonlinear magnetic circuit with lumped parameters [17] show that the double star provides a combination of phase shifts characteristic of a four-pole induction machine 2p = 4. Although, judging by the diagram, due to the presence of edge effects in the shortened machine, it turned out that the sum of the phase shifts of the magnetic fluxes of the teeth is somewhat less than 4n.

Conclusion. The proposed MHD devices can be used to create technologies for electromagnetic effects on the aluminum melt. The use of a controlled switching unit ensures the switching of the windings of the inductors, with a change in the tractive characteristics due to a change in polarity.

By switching a triangle to a star or by switching a star, one creates the necessary scheme suitable for flexible control of pumping, metering or mixing the melt. The study showed that the correct choice of the connection scheme and phase inversion allows for a continuous circular raster of flows in the cores. In an external magnetic circuit, the field is characterized by the sum of the fluxes of the cores and becomes the field of stray.

With any distribution of magnetic fluxes over the cores, the intensity of the magnetic field in the channel is higher than in the cores, creating the required tractive effort in the melt. This can be considered an advantage of the proposed MHD machines, since the magnetic induction of leakage fluxes in steel does not reach extreme values and does not cause premature saturation.

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DISTRIBUTION OF TELEPHONE LOAD IN THE NETWORKS OF OPERATIONAL AND TECHNOLOGICAL COMMUNICATION OF JSC "UZBEKISTAN RAILWAYS"

Khalikov A.,

Doctor of Technical Sciences, Professor, Head of the Department of Automation, Remote Control and Telecommunication Technologies in Railway Transport Tashkent Institute of Railway Engineers

Urakov O.

The applicant of the department "Automation, Remote Control and Telecommunication Technologies for

Railway Transport" Tashkent Institute of Railway Engineers

РАСПРЕДЕЛЕНИЕ ТЕЛЕФОННОЙ НАГРУЗКИ В СЕТЯХ ОПЕРАТИВНО-ТЕХНОЛОГИЧЕСКОЙ СВЯЗИ АО «УЗБЕКИСТОН ТЕМИР ЙУЛЛАРИ»

Халиков А.

Д.т.н.,профессор зав.кафедрой «Автоматика, телемеханика и телекоммуникационные технологии

на железнодорожном транспорте» Ташкентского института инженеров железнодорожного транспорта

Ураков О.

Соискатель кафедры «Автоматика, телемеханика и телекоммуникационные технологии на железнодорожном транспорте» Ташкентского института инженеров железнодорожного транспорта

Abstract

The article discusses the main requirements for the network of operational and technological communication, as well as analyzes the efficiency of operation and the efficiency of dispatch communication based on the data of the Signaling and Communication Directorate of O'zbekiston Temir Yollari JSC.

Аннотация

В статье рассматриваются основные требования к сети оперативно-технологической связи, а также анализируются эффективность функционирования и оперативность диспетчерской связи на основании данных Управлении сигнализации и связи АО «Узбекистон темир йуллари».

Keywords: operational and technological communication, types of communication, software, switching.

Ключевые слова: оперативно-технологическая связь, виды связи, программное обеспечение, коммутация.

Введение

На железнодорожном транспорте обеспечение безопасности и надежности перевозочного процесса заключается важнейшим критерием рыночной экономики. Одним из главных направлений удовлетворения требований в управлении процессами перевозками является усовершенствование систем и средств обеспечения качественных телекоммуникаций.

Наиболее сильное влияние на эффективность и безопасность перевозочного процесса оказывает качество систем коммуникаций акционерного общества «Узбекистон темир йуллари» (АО «УТЙ»), которое на сегодняшний день выполняет около 40 % грузо и более 70 % пассажирских перевозок республики [1, официальный сайт. - URL.: http://rail-wav.uz/rul.

От четкой и надежной работы устройств связи во многом зависит эффективная работа железнодорожного транспорта, при помощи которых осуществляется оперативное управление грузо-пере-возочным процессом на железной дороге и их взаимосвязь с отдельными подразделениями.

Качество перевозочного процесса на железнодорожном транспорте обусловлено своевременностью, безопасностью и надежностью отправления грузов и пассажиров к месту назначения. Эти показатели в основном зависят от успешности взаимодействия и функционирования подразделений и всех хозяйств, непосредственно участвующих в организации перевозочного процесса и эксплуатации подвижного состава.

В соответствии с потребностями системы управления железнодорожного транспорта все необходимые задачи и качество связи определяют с

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