Search results

This paper describes an algorithm evaluating the effectiveness of energy-saving devices and technologies, based on the methods of mathematical statistics. Diagram presented in the article. It can be applied in the traction system and power supply without traction. Approbation of the algorithm is executed in the traction power supply system. The developed algorithm includes five stages: 1. Stage calculate the required number of observations. The basis of this stage is to evaluate the dispersion and calculating on it the desired number of observations. 2. Stage of the collection and processing of data obtained before the implementation of energy-saving devices and technologies. Collection is carried out on of electricity consumption and factors influencing the process of electricity consumption. Processing includes the calculation of the correlation matrix, the coefficients of determination and the parameters of the regression equation. 3. Stage of the collection and processing of data obtained after the implementation of energy-saving devices and technologies. Data collection is carried out according to the parameters selected in step 2 and the processing is done by the calculation of the parameters of the regression equation. 4. Stage of comparing the data before and after the introduction of energy saving devices and technologies. Comparison of the data obtained before and after the introduction of energy saving devices and technologies produced using the Chow test and nonparametric mathematical statistics such as omega-square (Lehmann-Rosenblatt). 5. Stage of calculating electric power saving. The calculation is made on the consumption of electricity obtained by the regression equation before the introduction of energy-saving devices or technology by substituting the values of the factor after implementation and actual consumption of electricity after the introduction of energy-saving devices or technology. Approbation of the algorithm was successful.

The article presents statistical studies of acoustic control signals when diagnosing power transformers of the railway power supply system. Statistical processing of acoustic monitoring data was carried out on the example of transformers with different levels of insulation condition. Comparisons of histograms of the experimental distribution of amplitudes and dominant frequencies of signals with the nearest theoretical distribution laws, performed in the STATISTICA program according to control data obtained from the automated system. The conducted studies have shown a close correlation of defects registered by the acoustic method with the distribution of signals in the form of laws of distribution of random variables. It is shown that for power transformers with mechanical oscillations, both during the passage of the train and at idle, the distribution of amplitudes and dominant frequencies of the recorded signals corresponds to a uniform law. The distribution of amplitudes and dominant frequencies is not centered around a certain average value. For power transformers containing partial discharges, the cause of which is the deterioration of the insulating properties of the windings under the influence of high voltage, the best approximation, both amplitudes and dominant frequencies, showed the Lognormal distribution. The signals are centered around a characteristic mean value. When the train passes, the acoustic system registers both high-frequency signals from the PD and low-frequency signals from body vibrations. There are two components in the distribution law - uniform and lognormal distribution densities. Thus, by the type of distribution of the recorded signals, their amplitude and dominant frequency, it is possible to determine the presence of a defective state of the insulation of power transformers. The study was carried out with the financial support of the Russian Foundation for Basic Research within the framework of the scientific project No. 20-38-90231.

The article is devoted to checking the validity of the hypothesis that the information on a user's computer system, obtained on the basis of covert monitoring of standard peripherals allow timely recognize disloyal behavior and prevent the realization of the internal threats to information security, which is important for the information systems of rail transport.

Single-phase transformer with an additional tap at the middle point of the secondary winding is a very common element in the various electrical circuits, including on-board electric rolling stock. A typical case is powered from the transformer zero full-wave rectification circuit. The aim of the article is to provide a detailed description of the computer model developed by the author of said transformer, built on the basis of a combination of circuit and operational design principles. The proposed model can also be used to describe the process in a single-phase two-winding transformer without additional tap, given the possible connection group I / I-6 or I / I-0. Connection groups can be considered individually for each half of the secondary winding in case of using of additional tap. Shows an example of embedding the transformer model in a more complex computer model of the electric traction DC motors excitation current stabilization system, which includes a computer model of a saturable reactor, thyristor rectifier, system of pulse-phase rectifier control and control loop with a proportional-integral current regulator and boost nonlinearity. Obtained during the simulation graphics excitation current in the field winding of collector traction motor and its reactive component show that the above system of stabilization of the current and its computer model of functional and successfully fulfill their functions: at the downturn of the armature current excitation current is maintained by the growth of the current make-up of excitation control rectifier. The correct operation and ease of use of the developed computer model of a single-phase transformer with an additional tap at the middle point of the secondary winding is stated.

The article deals with the problem of diagnosing the technical condition of the collector-brush unit of DC motors. The topicality of this problem in the engines operating on the railway transport, which are in the most severe operating conditions, is particularly noted. These studies are aimed at improving the reliability of diagnosing the technical condition of the collector-brush unit through the use of a new method of diagnosing the condition of collector DC motors’ commutation. The proposed method of diagnosis is based on a new principle of processing diagnostic information about the spark pulses under the brushes. The article presents the histograms of the distribution of the pulses' intensity of different sections of the armature winding. The research conducted an experiment using a digital control device that allows to identify and digitize a useful diagnostic signal from multipolar brushes with a high sampling rate and transfer it to a computer. Analysis of the experiment’s results showed that the average value of the pulse’s area increases with increasing the spark’s intensity. Nevertheless, severe sparking at the collector leads to the law of distribution becomes double-modal, and as a result, dramatically increases the standard deviation of the values of the pulses’ areas. Described effect makes misinformation in the diagnosis procedure using the parameters of the laws of distribution of the spark’s intensity. The proposed method of diagnosis allows to eliminate this effect. The copyright for a new method of diagnosing is protected by a patent.

The article considers an approach that allows to reduce the asymmetry of consumed currents by traction substations of railways from a three-phase power supply system using a compensating device with an asymmetric structure installed at the substation. Reactive currents of the compensating device allow to redistribute between phases of the traction transformer active and reactive power of asymmetric traction load and to receive symmetric load of three-phase power supply system. The theorem is proposed to determine the conductivities and reactive currents of the branches of a compensating device with an asymmetric structure depending on the traction loads. The article presents the calculated expressions, which can be used to calculate the conductivity and reactive currents of the branches of the compensating device for any traction load of the feeders, in which the equivalent load, including the reactive currents of the branches of the device and the currents of the feeder zones will be symmetrical and active. As an example of the application of the theorem and the proposed expressions, a test problem is presented in which the secondary winding of a traction transformer with asymmetric traction load of feeders is considered, the conductivity of the branches of the device is calculated. With the use of vector diagrams shows the receipt of a symmetrical system of currents of the secondary winding of the traction transformer. Mathematical expressions allowing to realize the necessary law of regulation of reactive currents of the device are given. The necessary ranges control of reactive currents of the compensating device on traction substation on the set probabilistic laws of change of traction loadings are defined. Various options for the practical implementation of a compensating device that will provide the necessary inductive or capacitive current of each branch are considered.

The article describes two methods to estimate the rotor speed of the induction motor using special spectral components generated by the engine design. After you search for these components is possible to estimate the rotor slip. The aim is to compare these methods under different engine loads and to determine the most accurate method. The result is program algorithm for determining the rotational speed of the rotor of an induction motor, which can be used for a variety of practical tasks that require precise definition of speed, but there is no any access to moving parts to install the speed sensor or the use of sensors is undesirable revolutions.

One of the ways to increase the capacity of railways is to use long-distance freight trains with a distributed traction system. In order to reduce the influence of the human factor, it is advisable to use automatic speed control systems on the locomotives of such trains, that take into account the transients occurring in the train. Determination of the longitudinal forces that occur in the train can be carried out by using either a reference mathematical model of the train, or pre-calculated dependencies of these forces on the parameters of the train movement. The second method allows you to simplify the structure and improve the performance of automatic control systems.

The technique and algorithm of definition of consumption rates of materials on the current maintenance of a way depending on freight density, the passed tonnage, the plan and a profile of sites of a way, axial loadings of a rolling stock is given. Standards are developed on the basis of the analysis of the existing normative documents, statistical data from forms of primary accounting of PU-74 of the consumption of materials, annual reports of linear sites and other sources. Depending on service conditions standards are determined by analytical dependences and the correcting coefficients.

The need to apply various methods for predicting the technical condition of reinforced concrete supports of the contact network is currently a necessary condition for ensuring the safety of train traffic. Such a need arose due to the presence in operation of supports with extended service life, in the absence of a reduction in loads, without the presence of various kinds of redundancy. The article describes a method for predicting the technical state of the supports of the contact network. Solving the problem of exploitation, which consists in the fact that it is rather difficult to reveal the system of failures of the considered object of exploitation, under the influence of many factors. The probability of finding the contact network supports in a certain state is expressed through the statistical properties of the contact network supports, based on the change in the carrying capacity

In this article, the process of wear of the material of the ridge of the wheel brace during the movement of the locomotive in a curve of a given radius is considered. The methodology of the study considered in this article was that, based on the expression for the depth of penetration of the rail head into the material of the bandage ridge, the movement of the wheel along the inner rail in the curve was considered. It was taken into account that the contact point on the ridge of the bandage will move along the edge of the rail with slippage and that the contact area is a fairly narrow surface with a border close to an ellipse. Formulas for calculating the speed and the slip path of the contact point of the ridge of the locomotive wheel brace with the rail are obtained. As a result of the study, equations were derived to estimate such quantities as the volume, intensity and wear rate of the bandage (per revolution of the wheel). It is shown that the expressions obtained as a result of the work carried out can be used to calculate the intensity of wear of the brace ridge when the locomotive is moving in a curve of a given radius. The amount of the ridges material wear of the wheelset bandages can be determined on the basis of the equations obtained individually for a specific locomotive series and a given range of its operation.

The article presents a method of the additional resistance calculating of ground grid drainage unit. This work has two main objectives: development of algorithm for determining the optimal values of additional resistance and to study the possibility of reducing losses in reverse traction network through drainage unit of traction substation. The calculation is carried out with a view to ensuring the normative values of the protective potential on the grounding grid and minimize losses in the reverse traction network. The method is based on the application of the reciprocity theorem, which allows to change the direction of the currents from the source to the load on the reverse one if the system is linear. The calculation of the values of additional resistance and power loss in the reverse traction network for average current on the considered traction substation of the Western-Siberian railway. In results the selection method of optimal values for the additional resistance is offered. This method can be used for designing of traction substation grounding grid protection.

The factors affecting the operational reliability of the assembly platform of a rail service car maintaining the repair and installation on the railways are considered in the paper. An assessment and analysis of a system of quantitative indices of reliability is performed, the methods for their separate determination by mechanical equipment and hydro and electrical equipment is described. The strategy of maintenance and repair combined with the use of methods and means of a modern diagnostic system is considered; it ensures the estimation of the object reliability during its design, operation and repair.

The aim of the research presented in the article was to develop computer models for determining the electromagnetic fields (EMF) generated by three-phase 25 kV traction power supply systems (TPSS). In contrast to traditional single-phase TPSS, three-phase systems are electromagnetically balanced, provide symmetric loads of substations, increase voltages at current collectors of rolling stock, reduce asymmetry and non-sinusoidality in 110 - 220 kV supply networks. However, the issues of quantitative assessment of electromagnetic safety conditions in three-phase traction networks remain unstudied. To implement the formulated goal, we used the methods of modes and EMF simulation developed at the Irkutsk State University of Railway Transport, the distinctive feature of which is the use of phase coordinates; in this case, the models of TPSS elements are formed on the basis of lacelike equivalent networks. The simulation was carried out for three-phase TPSS schemes of different complexity, in which case the complex traction network was implemented by modifying the model of a real TPSS of one of the main railroads of Eastern Siberia. Simulation results indicated that compared to the typical TPSS 25 kV, the maximum electric field strength increases by 2.5 % in the three-phase system. The maximum value of the magnetic field strength decreases by 26 %. Similar indicators for average values are 2.6 and 19 %. The proposed methodology and the developed computer models can be used in the design of promising three-phase TPSS. In the conditions of power engineering digitization, the application of this technique in practice will allow to apply a scientifically validated approach to the analysis of electromagnetic safety conditions traction networks and to develop its improvement.

Example of the methods to evaluate conditions and reserve of transverse stability in CWR curves under abnormal track maintenance is discussed in the article. The author presents the results of the research of this method and also its positive effect is described.

The paper discusses the use of automated electricity metering systems to control parameters of the traction power supply system in terms of speed and heavy movements. As the main control system offered an automated system for monitoring energy efficiency of transportation process. The results of testing of the system considered in the measurement example, the boundaries of the active area of railways DC Shalya - Podvoloshnaya Sverdlovsk railway.

The algorithms and modeling program allowing estimating indicators of financial technological risk, based on a random process of dynamic risk.

The article considers the peculiarities of the transport network ports on the Baltic sea, the problems of optimization is to increase cargo turnover and the challenges associated with the modernization of the transport complex of Russia

The paper presents a comparative analysis of different methods of quantization of continuous signals, including optimal with the maximum entropy and the entropy – suboptimal, with various parameters of signal distribution.

The problems of optimization of organization of maintenance and repair of locomotives. The article presents new approaches for calculating the norms of spare parts and materials. Models of vehicle systems consisting of a fleet of operated locomotives are given, taking into account all conditions.

The article deals with the issue of improving the energy efficiency of DC and AC electric locomotives operated at the enterprises of JSC “Russian Railways». The main goals and objectives of the development program and energy strategy of JSC «Russian Railways» are analyzed and briefly considered. In accordance with these tasks, the relevance of scientific research in the field of improving the energy efficiency of electric locomotives is substantiated. The current data on traction rolling stock, on modern traction resource management systems and on Russian and foreign scientific research in the field of energy efficiency are analyzed. As a result of the analysis, it was found that most of the studies are aimed at studying the influence of key operational factors on energy efficiency indicators, so, in this case, on the specific power consumption for train traction. However, the reverse question has been poorly studied - the selection of the train mass and the technical speed on the basis of a preliminary assessment of the specific power consumption for train traction by analyzing the statistical data of trips on a certain section of the railway. The purpose of this study is to assess the possibility and develop a method for determining the optimal values of the key parameters of the operation of electric freight locomotives in order to achieve maximum operational efficiency in relation to them according to the criterion of energy efficiency. Two models were created in the program «Complex of calculations of traction power supply» (CORTES) - for DC and AC electric locomotives, describing the dependence of the energy efficiency indicator (specific power consumption for train traction) on operational indicators, such as the train mass and the technical speed. The initial data for further modeling were obtained by modeling trips on a conditional site.

Transportation in tank cars of viscous liquid cargo (fuel oil, paraffins, industrial oils, cracking residues, etc.) is difficult with their solidification, accompanied by a sharp increase in viscosity. In fact, this leads to the need to warm up or partially warm up the transported oil product before unloading, usually carried out as a gravity discharge, in order to restore the fluidity of the delivered oil cargo. The process of unloading in this case with heating leads to a significant increase in the cost of transporting petroleum products, including the downtime of tank cars, and in general, a decrease in the turnover of rolling stock. According to the analysis carried out to determine the costs of the technological process of heating frozen petroleum products transported by rail, about 600 thousand tons of conventional fuel are spent per year, and the idle time of tank cars under unloading and subsequent cleaning of boilers from high-viscosity residues of oil cargo exceeds 1 million car-hours. The urgency of the issue of reducing the cost of railway transportation of viscous cargo is due to the intensive development of the Northern and Eastern regions of the Russian Federation. Important factors for transportation in these conditions are not only the negative average daily air temperature, but also long distances. The issue of reducing the cost of transportation of viscous petroleum products at low air temperatures is considered. Viscous petroleum products, when thickened, turn into a rheological liquid, which does not have a clear interface between the liquid and solid phases. The methods of transfer to the stratified state of hot fuel oil during its slow cooling and partial solidification with the formation of a heat-insulating layer of solidified fuel oil are applied. The positive effect is achieved by reducing the time and cost of thermal energy for unloading the delivered oil product by reducing the rate of its cooling during transportation. This, in turn, is achieved by suppressing the natural convection of the hot oil product on the cold walls of the boiler of the tank car in the first few hours after filling the tank. From the comparison of the experimental data and the calculation results, the values of the empirical coefficients of the equation for the heat transfer coefficient of liquid petroleum products are selected. The standard deviation of the absolute temperature of the liquid petroleum product was 8 %.

Corrosion processes at various constructive changes of grounding system of traction substation are considered: construction of new cable lines, expansion of the territory of substation, etc. Calculation of corrosion processes of the grounding system consisting of three electrodes is carried out: steel in concrete, the metal gauze in soil, a steel vertical electrode in soil. Results of calculations are presented, the analysis of corrosion processes is made under various conditions.

Is executed the analysis of the special features of the territorially distributed objects of rail transport for developing the systems of video surveillance and video registration. Is proposed the three-stage design procedure of such systems, at basis of which lies the separation of entire system into the zones of video surveillance, zones of video registration and the information clusters, which ensure the optimization of system on the criterion of minimum expenditures.

The article is about defining corrosion state of overhead structures underground part. Specially designed concrete models are used for experiments and calculations. These models are made with the fabric technology of overhead structures creation. «Steel - Concrete» interface region parameters are calculated with a help of transient process which situated when DC power supply is connected to the scheme. There is a formulas and a methodic for calculation needed parameters. In the end of the article theoretical curve is located. It exactly coincides with an experimental curve.