Volume 88, Nº 3 (2017)

Results are presented for the construction of a model of an energy-supply parameter characteristic for the transportation process, “electric-energy consumption for traction (plan),” based on the identification thereof with actual production and economic parameters by the example of one of the branches of JSC Russian Railways. The research was carried out based on a database created for monthly actual values over a long period, from 2007 to 2016. A methodology and results are presented for statistical studies of the parameter “electric-energy consumption for traction (plan)” in conjunction with 20 parameters, including “sectoral speed,” “average weight of the train,” “transportation costs.” The methodology involves choosing the factors for a multifactorial model and elimination of the consequences of multicollinearity based on the results of cluster analysis and constructed dendrograms. Variants are presented for the construction of multifactorial models to predict and manage the parameter of “electric-energy consumption for traction (plan)” for control and risk-management tasks. A variant of construction of a multifactorial model for predicting and control of the parameter “electric-energy consumption for traction (plan)” for control tasks and risk-management is given. As a mathematical tool for constructing the multifactorial models, a technique of linear regression equations has been used. The construction of dendrograms and obtaining the regression equation coefficients have been carried out using the Statistica software package. Using the multifactorial model results in improvement in the predictive accuracy of the “electric-energy consumption for traction (plan)” parameter measured with a MAPE estimate, from a 15% level to a level better than 6%.

In many applications, objects are distributed and described by equations of mathematical physics. Such objects are often described by models with lumped parameters. Therefore, improving the accuracy of the description of a distributed object on the basis of a model with lumped parameters is an urgent problem. The aim of this paper is to develop a method for adaptive identification of long-line models on the basis of equations with fractional-order differences in the presence of noise. In many applications, the spatial coordinate can be considered constant and measurements can be performed at the beginning and at the end of the line. For such cases, the object transfer function is an irrational function of variable p. It is shown that an object with an irrational transfer function can be approximated by equations with fractional-order differences. A mathematical model of a long line in the form of a finite impulse-response filter with fractional-order differences is proposed. Such a filter combines the advantages of the known infinite impulse-response and finite impulse-response filters: it has a comparatively small number of coefficients and remains stable at any limited values of the coefficients. On the basis of the recurrent least-squares method, an algorithm for adaptive identification of long-line models with fractional-order differences was developed. A computer experiment showed a high accuracy of the proposed model as compared with the known infinite impulse-response and finite impulse-response filters. In addition, the identification algorithm on the basis of the proposed model showed the higher noise immunity. The obtained results can be used in the development of adaptive-filtering algorithms for long lines (communication channels, track circuits, power lines).

This paper considers the problem of digital information processing by the example of encoding and decoding the control signal of a wireless working cycle correction technology for an autonomous electrical grid. Being subjected to random interferences or intentional attacks, the encoded signal may be decoded incorrectly, causing disruption (change) in the system operation. In this work, we simulate different types of interference. For subsequent software implementation, algorithms are proposed that simulate group and single errors, as well as errors that are combinations of these two types. The effects of errors of different types on the results of decoding the compressed and uncompressed image files are investigated. This paper also proposes some options for representation of graphic files encoded in the software implementation. The files are encoded using the Reed–Solomon codes and are decoded using the Guruswami–Sudan list-decoding algorithm. A comparison between the files obtained after decoding for different types of errors simulated in the process of encoding is presented.

Results of simulations of the processes of changing currents and voltages in power circuits of VL10 (VL-10W) locomotives with traction motors, which are connected in series, in cold insulation have been considered. Taking the thermal state of the insulation structures of traction motors of locomotives into account is a new approach in simulations of electrical processes in power circuits. Such a differentiated approach to simulating the electrical processes in power circuits of locomotives became possible when the capacitive components of anchor and pole windings of traction motors in locomotives were studied and taken into account in the equivalent circuits, as well as their temperature dependences. In this work, the results of simulations of the processes of changing currents and voltages in power circuits of VL10 (VL-10W) locomotives during a start from rest in the case of series connection of traction motors with insulation temperature of their anchor and pole windings equal to 20°C. The results of simulations are shown as graphic time dependences of currents and voltages in the main elements of a locomotive power circuit.

This paper considers the implementation of an automated system for monitoring and controlling switching devices in remote-controlled stations. Switching-equipment breakdowns in the process of operation that cannot be quickly tracked without being at the location itself create a problem. The concept of a visual-inspection system for remote devices is developed. The system operates in the standalone mode without human intervention, allowing the dispatcher to visually monitor the condition of plants. The control zone covers the external condition of equipment and the heating parameters of its current-carrying parts. The visual-inspection system is designed to work with the telemetry and remote-signaling systems already installed at a plant. The proposed technology provides the power dispatcher with the complete information on a plant and allows the maintenance personnel to quickly respond to emergencies so as to prevent electricalequipment breakdown and accidents.

This paper presents a methodology and a specially developed software toolset for design and verification of real-time control algorithms and programs. The real-time control algorithm must timely execute required actions in accordance with the current situation reflected by the parameters checked. This kind of algorithm is an example of a mission-critical application. Unfortunately, these algorithms suffer from mistakes and errors resulting in disasters, large material losses, etc. That is why the process of design, development, and verification of real-time control algorithms is rather time- and labor-consuming. Verification usually involves many-staged debugging on special testbeds. Some errors in control algorithms are due to misunderstandings between the participants of the control-system development process: specialists in particular subsystems, system engineers, and programmers. The proposed methodology makes it possible to exclude programmers from the process of control-software development, thereby reducing the number of errors and the labor cost. The main idea is to design and use a special visual notation intuitively understandable for system engineers. This feature should reduce the number of errors in control algorithms due to eliminating the “broken phone effect” when the programmer can misunderstand a program specification and implement it in the wrong software. The toolset consists of special software modules, including modules for visualization, construction, and verification of onboard real-time control algorithms. All modules are executed from an integrated development environment.

One industrial application of linear motors is as working-body drives of vibration-technology machines. Such drives allow manufacturing of equipment with very low energy consumption and material costs. This paper presents the results of research on substantiation of the prospects of application of linear electric motors as drive vibration-technology machines. The results of designing a linear dc motor are presented. This paper describes the design of the electric motor and its operation in the hold-down and vibrating modes. The main technical characteristics of the motor are given. Simulation of the electric-motor electromagnetic field based on symmetrical setting of the task for the Poisson equation was performed with a view to specifying and verifying the preliminary calculation data. The results of the calculations and simulations show that it is possible to create low-cost, manufacturable, and reliable electrical motors for a linear vibratory actuator.

A Phasor Measurement Unit (PMU) is an important device for monitoring the wide-area power distribution network. Placement of the PMUs across the network enables reliable monitoring of the network to identify the faults in the bus system. Due to the increase in the installation cost of the PMUs, optimal placement of the PMU is a significant task. But the existing techniques do not provide the optimal solution for the PMU placement. To overcome this issue, this paper proposes a novel Clustering-based Hidden Markov Model (CHMM) optimization approach to achieve optimal placement of PMUs in the power distribution network. Optimal PMU placement is achieved by applying cluster formation in the bus system to extract the data with neighboring buses. Best optimal position for placing the PMU is estimated by using Fuzzy logic-based rale formation to update the binary table of the bus system. The HMM approach is used for updating weight in the cluster formation. Our system is implemented in various bus systems like IEEE 28-bus system, 69-bus system and also in Karnataka 155-bus system. The proposed approach is implemented in the IEEE bus system and Karnataka Power Transmission Corporation Limited (KPTCL) bus system and compared with the existing approaches, based on the total number of PMU placement. The proposed approach achieves better performance in the optimal placement of PMU than the existing optimization algorithms.

In electrified transportation, the rail network is used as a return conductor of the traction network. The resistance of the components of the rail network to the traction current within the track circuits is stabilized by the rail bonds (RBs), which are classified as “welded,” “plug-in,” and “spring” rail bonds. Depending on the type of traction, copper or steel–copper RBs of various sections are used; therefore, the current conductivity of the rail line depends on the design of the rail network and the operating conditions and maintenance of the track circuits. Analysis of the distribution of failure in the track-circuit elements shows that the faults in the rail bonds are one of the leading causes of failure in the track circuits. For example, during the fourth quarter of 2016, this figure for the Kuibyshev Railroad, which is a branch of OAO Russian Railroads, was 20%, with the track circuits accounting for 57% of the total number of failure events in the devices of the railroad automation and telemechanics systems. The number of failure events has increased in 2 maintenance sections out of 11 compared with the third quarter of 2016 including failure in rail bonds. This article deals with the problems of continuous monitoring and diagnostics of the conduction of the rail lines on the basis of the principles of invariance to the disturbing actions.