Electrodynamic Braking Research Articles

An Estimation of the Energy Savings of a Mainline Diesel Locomotive Equipped with an Energy Storage Device

The method of improving a two-section mainline diesel locomotive by using energy storage in the traction system is considered. A mathematical model was developed to study the movement of a diesel locomotive based on the recommendations and provisions of the theory of locomotive traction. For this purpose, the movement of a diesel locomotive as part of a train along a given section of a track was studied. It was determined that the use of an energy storage device on a diesel locomotive will allow up to 64% of the energy spent on train traction to accumulate. The use of energy storage in the accumulator during electrodynamic braking ensured a reduction in fuel consumption by about 50%, regardless of the options for equipping the traction system of the diesel locomotive with an energy accumulator. It is established that regardless of the options for equipping the traction system of the diesel locomotive with an energy storage device, the indicators characterizing the degree of use of the diesel engine do not change. These research results can be used in works devoted to the improvement of the control system of energy exchange between the accumulator and traction engines of diesel locomotives.

Sound Generation by Metro Trains during Braking and Its Suppression Method

The causes of acoustic noise occurring during braking of electric vehicles, in particular, in the metro, were analyzed. The spectrum of such noise was measured, and it is shown that high-frequency discrete tones are excited by braking resistors, applied for electrodynamic braking of electric vehicles. Three proposed mechanisms of electromechanical interaction in a Fecral plate, which is a braking resistor element, were considered: the Ampère force and linear and nonlinear magnetostriction. It was shown that predominant odd harmonics indicate the presence of a significant piezomagnetic effect and the inverse effect of linear magnetostriction in the Fecral alloy. A phenomenological approach was used to calculate the piezomagnetic tensor elements for Fecral. Calculations by the finite element method showed that asymmetric cuts introduced into the plate may significantly decrease intensity of acoustic vibrations excited by the braking resistor.

Justification of the Structure of the Electric Traction Drive of the Electric Locomotive for Railway Quarry Transport

Purpose. The study is aimed at substantiating the structure and determining the main parameters of the traction electric drive of an electric locomotive for railway quarry transport, taking into account its modes of operation. Methodology. The research was carried out by means of mathematical modeling, which included solving the traction problem and evaluating the parameters of the energy exchange processes between the components of the traction electric drive. The simulation was carried out for the movement of the train along the track section and during shunting, which differ significantly in their mathematical description. During simulation of movement along the track section, the traction problem was solved using recommendations for traction calculations for train operation. A simplified model was developed to simulate movements during shunting. Determination of the parameters of the traction electric drive components is carried out by analyzing the processes of energy exchange in the traction electric drive based on the power balance. During the studies, it was assumed that the on-board energy storage in the traction mode feeds the traction electric motors of the booster section. In the electrodynamic braking mode, the energy accumulator stores energy from all traction electric motors of the electric locomotive. Findings. The authors obtained time dependences of the parameters that characterize the train movement at all stages of the cycle «empty half passage – loading – loaded half passage – unloading» (on the example of an electric locomotive for PJSC «Ferrexpo Poltava Mining»). The analysis of the obtained dependencies made it possible to determine the parameters of the main components of the traction electric drive for the proposed storage operation scenario. It was established that the energy capacity of the energy storage should be 250 kWh for one movement cycle. The energy storage power is 6000 kW. Originality. The authors of this paper for the first time proposed the structure of the traction electric drive of an electric locomotive for quarry railway transport, in which the electric motors of the control electric locomotive are powered from the catenary network, and the electric motors of the booster section are powered from the energy accumulator and are included in the operation at a load that exceeds 50% of the nominal one. Practical value. The practical value lies in the developed mathematical models of movement and energy exchange processes, which can be applied to the study of traction electric drives of vehicles of various purposes.

Optimization of Train Energy Cooperation Using Scheduled Service Time Reserve

The main aim of the paper was to develop an innovative approach to the preliminary estimation possibility of train energy cooperation based on data from timetables, without traction calculations. The article points out the need to strive for sustainable and environmentally friendly transport. It was pointed out that rail transport using electric traction is one of the more ecological branches of transport. It also offers a number of possibilities for improving energy efficiency and reducing energy consumption, one of which is the recovery and reuse of energy lost in the electrodynamic braking process. The main ways in which such energy can be used are listed, but the focus is mainly on the aspect of the so-called “energy cooperation” of trains. Then, the current state of the research and knowledge on the narrowed scope of rail traffic management and recuperative braking in rail transportation is presented; an innovative approach to the indirect optimization of the amount of recuperated electrical energy immediately usable by another vehicle by maximizing the duration of energy co-optimization is proposed; and the authors’ function is proposed to enable optimization, taking into account various parameters. The optimization was performed with the use of a proprietary, multi-criteria objective function and the Solver optimization module. Finally, the results obtained using the proposed approach are presented and illustrated with the example of train timetables used by some of the largest railway stations in Poland.

Performance assessment of railway track under the impact of longitudinal forces during the implementation of maximum traction modes when using electric locomotives with an asynchronous traction drive

Strategic task of increasing carrying capacity of railways requires a constant increase in the mass of trains due to the passage of heavy and coupled trains. Development of heavy haul traffic is one of the most significant technological solutions aimed at increasing efficiency of using the infrastructure's capacity. In this case, capabilities of the track infrastructure become decisive. The article presents the results of experimental studies of the performance of a continuous welded track under the influence of longitudinal forces arising from the motion of modern locomotives with an asynchronous traction drive in the modes of maximum traction and electrodynamic braking. It is shown that it is necessary to take these forces into account when calculating continuous welded track for strength and stability. The object of testing was a railway track under the influence of increased longitudinal forces during the motion of the 2EV120 electric locomotive with the implementation of various traction modes and electrodynamic braking. Tests were carried out on three sections of the Test Center's track of the JSC VNIIZhT, the experimental joint was equipped with special strain gauge pads designed to measure longitudinal forces. According to the research results, it can be noted that the longitudinal forces in the rails caused by the implementation of the maximum traction forces and electrodynamic braking can reach up to 25 % of the maximum temperature forces. The real forces of resistance to the longitudinal displacement of rails in the nodes of intermediate fasteners when tightened with the force provided by the standards are about 3-4 kN, which is significantly lower than the standard values of 14-16 kN, and may be a consequence of the wear of the elements of intermediate fasteners and the state of friction surfaces. These phenomena can cause longitudinal displacement of both individual rail lines and the grid as a whole. The development of a set of measures to prevent this phenomenon requires a wide range of studies in real operating conditions, including optimization of traction and braking modes of driving heavy haul trains.

Study of the functional diagram and algorithm of tracking system for electrodynamic braking of DC electric train

One of the key ways to save operating costs in suburban traffic on lines electrified with direct current is to increase the return of electric energy when the drivers use the regenerative braking mode. Electrodynamic braking control systems that track the magnitude of the voltage of the contact network can increase the percentage of return of electric energy from the use of regenerative braking due to the rapid redistribution of energy generated by traction motors. Similar systems (the so-called tracking systems) are used on DC electric trains with an asynchronous traction drive. In this work, authors analyzed an electrodynamic braking system for a DC electric train with a collector traction drive, which regulates the recovery current by changing the resistance of the braking resistor, and the armature current due to the magnetic flux of the motors. Characteristics of the pulse braking resistance controller for the current settings of the 250 and 350 A armature were calculated. Functional diagram of the tracking system with a description of its individual elements is developed. On a simulation model, electromagnetic processes in the power circuit of an electric train were studied with a changing current consumption. Based on the analysis of the model results, the ability of the tracking system to regulate the armature current with full absorption of electricity by the consumer is shown. The article provides the refined algorithm for the transition of the servo system from the mode of regenerativerheostatic braking to rheostatic with excessive generation of electricity. The developed algorithm of the tracking system provides a stable implementation of the braking force in the entire range of speeds and at various levels of consumption of generated electricity. A rheostatic braking circuit with stabilization of the maximum value of the excitation current at low speeds is proposed.

Levitation Characteristics of a Transport Installation with an Electrodynamic Suspension During a Longitudinal Joint with Road Track

Aim:to propose a technical solution to ensure the lateral stabilization of the vehicle with an electrodynamic suspension. Development of a method for calculating the levitation characteristics of a transport installation with an electrodynamic suspension in the presence of a longitudinal joint in the track. Analysis of the results of theoretical studies.
 Мaterials and methods: The article used the methods of the electromagnetic field theory, generalized functions, Fourier transform, analytical and numerical methods for determining quadratures. The program for PC was developed in the Fortran language.
 Result: to ensure lateral stabilization of the vehicle with an electrodynamic suspension, it was proposed to introduce a longitudinal insulating joint into the structure of the track bed. A mathematical model is proposed for this system of electrodynamic suspension in approximation of an infinitely wide track structure of rectangular cross section.
 A mathematical model is proposed for this system of electrodynamic suspension in approximation of an infinitely wide track structure of rectangular cross section. Numerical integration of these equations was performed by applying the Gauss formula and the Philo method. The results of the calculations allowed us to obtain a number of graphical dependencies of the levitation characteristics on the magnitude of the lateral displacement of the carriage electromagnet from a relatively symmetrical position.
 Conclusion: thus, the obtained results of the study fully meet the goal of determining the parameters of the side stabilization of the vehicle with an electrodynamic suspension with a track, containing a longitudinal joint under the assumptions made.
 Comparison of the proposed method with other proposed stabilization methods does not reveal the decisive advantages or disadvantages of the new method. In most cases, its most serious drawback is its low levitation quality. However, it is significantly reduced if the movement of the high speed ground transportation vehicle occurs predominantly at high speed, at which the force of aerodynamic drag prevails over the force of electrodynamic braking.
 Same relative is and the dignity of the system-high lateral rigidity. The reason for this is that the demands on the lateral stiffness can be quantified only formulated in relation to a particular track HSGT taking into account the timetable and other factors.
 In fact, the main destabilizing influences in sideways are inertia at motion on component and crosswind. Its role in choosing the stabilization system could play and other tasks the system subsystems HSGT.
 For example, installing additional stabilizing magnets can make it difficult to escape the passenger compartment from the magnetic field. Plays a role also principle and system design of traction. From the above it is clear that the final choice of the lateral stabilization of the research at this stage would be premature.
 Proposed and studied in this article a new way to stabilize should be regarded as another possible along with the preceding. The answer to the question on the competitiveness of the new method must be bound to the characteristics of specific trails HSGT. Necessary and further refinement of results associated with the more strict account of edge effect, as well as consideration of the case of uninsulated interface.

Monitoring system of electrodynamic braking of DC electric train with collector traction motors

High proportion of electric trains with collector trac-A monitoring system of electrodynamic braking has been develotion motors in the multiple unit fleet and its low cost in comparison ped with preservation of the electric train standard equipment. It al-with electric trains with an asynchronous traction make it neces-lows regulating the recuperative current depending on the possibility sary to improve the control system of motor collectors. One of the of its consumption by changing the resistance of the braking resistors. ways is to create devices to improve the efficiency of recuperative Imitation model of DC electric train power circuit in the electrobraking. dynamic braking mode with a monitoring system was developed.It takes into account the influence of eddy currents in the motor frame, armature current ripples and the catenary voltage increase during recuperative braking.Electromagnetic processes in the electric train power circuit are investigated. Analysis of the obtained oscillograms shows the change in the armature current and the catenary voltage within the specified limits in the braking mode. Recuperative current regulator is tuned to an aperiodic transient with a time equal to 0.015 s.The paper shows possibility of the monitoring system to regulate the armature current in the recuperative mode together with the automatic braking control system in case of increasing the catenary voltage. When the voltage fails, the monitoring system is not able to limit the increasing braking current, its reduction is effected by the magnetic flux of the traction motors.Adjusting characteristic and the technical effect from the implementation of the monitoring system are calculated. The possibility of reducing the electric power consumption by 4.62 % is shown.

A Simulation Model of a Servo System of a Regenerative-Resistor Braking of a DC Electric Train

The possibilities to improve the energy indicators of dc electric trains with commutator traction motors are considered. The features of the power circuit structure implementing contactr–resistor starting and regulation of velocity in the traction and braking modes using rheostat and regenerative braking are shown. Ways to improve the power circuit and control system are proposed allowing increasing the energy efficiency of regeneration. The servo system of regenerative-rheostat braking and a mathematical model of the power circuit as applied to electric trains of ED4M series are developed, and the parameters of the braking resistors and method of regulation of their resistance in the mode of electrodynamic braking are determined. The quality of regulation of the regeneration current is determined by the proposed servo system ensuring stabilization of its value with the change of the overhead system voltage. The possibility of increasing the energy supplied to the power source in the mode of regenerative-rheostat braking by 3–6% is shown. It is recommended to use an artificial neural network to increase the operation speed and regulation accuracy allowing connecting the pulse converter control system and automatic braking control system.

MODEL OF THE TRACTION ASYNCHRONOUS ELECTRIC DRIVE IN THE MODE ELECTRODYNAMIC BRAKING WITH A SCALAR CONTROL SYSTEM

This article is devoted to the problem of traction asynchronous electric drive operation in normal and abnormal conditions in the mode of electrodynamic braking. The proposed simulation model allows us to study the dynamical processes that arise in a traction asynchronous electric drive while driving on sections with different coupling coefficient of wheel pairs with a rail. The simulation model is rather versatile, which allows us to analyze in detail the electromagnetic and electromechanical processes occurring in a frequency controlled driven asynchronous electric drive taking into account changing conditions of rolling stock operation in electrodynamic braking, to evaluate the energy and operational parameters, to investigate the influence of parameters of the frequency converter, traction engine, parameters links of direct current to the nature of the transition processes, using modern methods of mathematics some simulation. As an example, the results of the simulation of a traction asynchronous electric motor with a scalar control law in the mode of electrodynamic braking with stabilization of the voltage in the DC link and the control of the braking effort, depending on the coupling coefficient of the wheel coupling with the rail, are given. The proposed system of protection against excessive slipping and skid wheel pairs can prevent the occurrence of abnormal operating mode of the traction asynchronous electric drive in the mode of traction and electrodynamic braking with a sharp change in the coupling coefficient of the wheel coupling with a rail, to identify the restoration of a satisfactory coupling coefficient and to analyze the need for adjusting the traction and braking torque of the traction asynchronous electric motor depending on the condition of the surface of the rails.

The Safety Rotor—An Electromechanical Rotor Safety System for Drones

We propose a novel rotor safety mechanism for rotary-wing small unmanned aerial vehicles, such as quadrotors, that avoids problems associated with cages, rotor shrouds, and obstacle avoidance safety systems. The system works by using a passively spinning hoop as a mechanical interference sensor; changes in hoop speed are detected with a reflective IR sensor, which triggers an electrodynamic braking circuit. Experiments demonstrated that the system can rapidly detect incipient collisions and bring the rotors of a retrofitted DJI Phantom 3 to a halt from flight speed within 0.06 s of contact. In testing with finger proxies and surface collisions, the safety rotor provided an effective mechanism for reducing the severity of rotor injuries during impact.

Wheel life prediction model – an alternative to the FASTSIM algorithm for RCF

ABSTRACTIn this article, a wheel life prediction model considering wear and rolling contact fatigue (RCF) is developed and applied to a heavy-haul locomotive. For wear calculations, a methodology based on Archard's wear calculation theory is used. The simulated wear depth is compared with profile measurements within 100,000 km. For RCF, a shakedown-based theory is applied locally, using the FaStrip algorithm to estimate the tangential stresses instead of FASTSIM. The differences between the two algorithms on damage prediction models are studied. The running distance between the two reprofiling due to RCF is estimated based on a Wöhler-like relationship developed from laboratory test results from the literature and the Palmgren-Miner rule. The simulated crack locations and their angles are compared with a five-year field study. Calculations to study the effects of electro-dynamic braking, track gauge, harder wheel material and the increase of axle load on the wheel life are also carried out.

RESEARCH OF SUCCESSIVE EXCITATION ELECTRIC MOTOR DYNAMIC MODES WITH PULSED SCHEMES OF THE ELECTRIC DRIVE REGULATION

Purpose: The purpose of the work is to research the dynamics of DC motor of series excitation with pulse speed control and determine the possibility of the drive circuit simplification. Research methods: With the help of simulation and analytical methods of calculation techniques developed a simulation model, identified the advantages of using a modernized impulse control scheme. The obtained results: The modernized scheme of series excitation DC current motor pulse control is designed. For the proposed and existing pulse regulation schemes the models are developed; they help to investigate the electromechanical processes of electric drive in these schemes and to perform the comparative analysis. The results of the modernized DC motor speed impulse control scheme investigation in the acceleration mode, overrun and electro-dynamic braking are given. Scientific novelty: Developed advanced pulse regulating sequential excitation DC motor scheme. For existing and proposed schemes impulse regulation developed models that allow study of electromechanical processes in electric drive for existing and proposed impulse control schemes. The practical significance: It is shown that the addition of a shunt field winding diode to pulsed regulator scheme reducing the rate of current decay in the winding. It is determined that the proposed upgrade allows to use electro-dynamic braking mode at the motor self-excitation. The proposed scheme design avoids the use of additional independent power sources and simplify the technical implementation and reduce costs.

Determination of Longitudinal Forces in the Cars Automatic Couplers at Train Electrodynamic Braking

During the research an analysis of forces which arise at the car automatic couplers in the course of electrodynamic braking of a train moving on the given railway profile has been performed. As the initial data dependences of the train velocity and the passed distance on time were taken. The obtained results demonstrate that at braking the maximal longitudinal forces in the automatic couplers are practically independent from the location of empty cars group along the train. The allowed compressive force value of 500kN for empty cars is not exceeded on condition that they are located in the last third of the train length.

On Electrodynamic Braking for Small Wind Turbines

Straightforward analysis can show that it is difficult to implement a successful electrodynamic braking system for a small wind turbine system, i.e. of swept area less than 200 m2 and power rating of 50 kW. Two principal difficulties are: (i) the peak short-circuit torque of the electrical generator can be far too low to overcome the torques associated with the wind turbine rotor, even at wind speeds close to rated; (ii) the energy dumped into the generator during braking is significant and can cause swift heating to high temperatures. Transient electrical effects can also lead to electrical and electronic component failures. Documented failures in machines of up to 10 kW indicate that it is the case that electrodynamic braking is not well understood throughout the industry. Additionally, the academic literature on the topic is sparse. In this paper, we show how very straightforward analysis can shed light on the edge cases for electrodynamic brake systems and help to avoid expensive errors.

Схема для выбора нужного варианта электродинамического торможе-ния асинхронного двигателя

The proposed scheme for fast selection of electrodynamic braking of an in-duction motor. Considered five options schemes electrodyne-economic deceleration. Need option scheme braking is set horizontal-LEM.

The efficiency of condenser energy-storage systems for underground wagons

A procedure for determining the efficiency of condenser energy-storage systems that are installed in underground cars for receiving electric power for traction electric cars working in a recuperative-braking regime is proposed. It was suggested to carry out comparative analysis of the efficiency of energy-storage systems on the basis of the following parameters: index of electric-power recovery in a full start-brake cycle of the wagon operation, relative determination of electric-power recovery in the braking regime and electric-power loss in the active regime of car operation, index of electric-power recovery in electrodynamic braking of traction electric cars, and relative evaluation of the mass of energy-storage systems. It is proposed to analyze the efficiency of energy-storage systems taking into account their design features. Energy-storage systems can be manufactured in a monoblock or stepped design. The proposed procedure of comparative analysis of the energy and mass-dimensional characteristics of underground cars with energy-storage systems allow their operation to be evaluated with a minimum number of source data. Installation of energy-storage systems increases the mass and energy expenditure during wagon operation, but this loss is significantly less than the energy volume recovered with an energy-storage system in a regime of recuperative braking of traction electric cars. Energy-storage systems allow one to create effective systems of autonomic recuperative braking on underground cars. A stepped design of energy-storage systems decreases their mass-dimensional characteristics and increases energy efficiency. The only real disadvantage of energy-storage systems preventing their use is their large size.

Analysis for Size of Ultra-Capacitor Bank to be Installed on 1.5kV System for Energy Storage during Regenerative Braking DC Drives

Economic indicators of electro-dynamic braking have not been properly estimated. Vehicles with alternative power trains are in transitional stage between developments of pollution - free vehicles. According to these aspects the investigation on conventional hybrids drives and their control system is carried out in the paper. The equations that allow evaluating effectiveness of regenerative braking for different variants of hybrid drive are given. Suitable size of ultra-capacitor for efficient energy storage medium in all hybrid electric vehicles has been evaluated. This paper also discuss the advances in double layer electrolytic capacitor technology have opened new areas to complement batteries as a storage medium. Equations for both constant current as well as constant power discharges are discussed. An iterative method for determining the minimum number of ultra-capacitor cells is introduced. The effects of ultra-capacitor sizing on the rating of interface power electronics are examined. Keywords - Ultra-capacitors, hybrid electric vehicles, energy storage, diesel locomotives, braking. I. Introduction Evaluation on diesel loco Vehicle's, indicates 20-40 % of mechanical tractive power is lost during braking. Estimation of recovered energy is very important (5). When a vehicle brakes, energy is released to grate, most of this energy is lost in the system. The challenging alternative is to store the braking energy and to use it during acceleration operation of the vehicle. Conventional diesel locomotives powered electrical vehicles cannot use regenerative brake energy. High interest and the onrush of hybrid vehicle are conditioned by a number of hybrid drive advantages:  Decreasing of fuel consumption and of exhaust emissions. (In India per day petroleum consumption in year 2010 was 3,116.22 barrels /day).  Possibility of breaking energy regeneration.  Possibility of using in hybrid vehicles with decreased volume preserving dynamic characteristics.  Increase of efficiency coefficient due to serial and multiple energy conversion.  High percentage of recovered energy. Estimation of recovered energy is very important. It is needed to reduce electric demands.  It can be a new energy savings opportunities and power will help in supply optimization, in case of hybrid traction vehicles systems, which are using regenerative braking energy. Ultra-capacitor technology has been commercially available for over the past decade. They can store much more energy than conventional capacitors and are available in sizes up to 4000F with voltage ratings of up to 3V per cell. They can be discharged or charged faster than batteries and can deliver 10-20 times more power e.g. ultra- capacitors typically have 10 times the specific power (W/kg) as well as a much lower charge time when compared to lead acid batteries. They also offer 10 to 100 times the energy density (Wh/Kg) of conventional capacitors. In terms of energy and power density, ultra capacitors can therefore be placed between batteries and conventional capacitors.

Energy of electrodynamic braking of the locomotive as a source to activate the air-fuel mixture of diesel ozone

In the article the use of energy of braking of locomotive for activating the fuel-and-air mixture is analytically substantiated. The possible methods of activating are analysed and the method of ozone activating of fuel is offered. The results of experimental researches of influence of the ozonized fuel on its physical and chemical properties as well as on the working process of diesel are presented.

ELECTRODYNAMIC BRAKING IN HIGH‐SPEED RAIL TRANSPORT

The paper considers electrodynamic braking of trains, which is of particular importance for high‐speed railway transport from theoretical and technical perspectives. Braking methods used for high‐speed trains should ensure compatibility and redundancy of braking systems. They include a mechanical method (based on adding frictional disks to wheelsets), as well as magnetic braking, which is being currently implemented and based on eddy currents, etc. High‐speed trains have AC/DC engines, for which the principles of electric braking can be applied. Electrodynamic braking is of particular importance for high‐speed transport using linear motors and developing the speed of 400–500 km/h. These traction rolling stocks will not have commonly used trucks. The tests in this area are being conducted in Japan and Germany now. The paper suggests some theoretical and practical solutions to these problems. Schematic diagrams of the locomotive braking and ways of controlling the braking force by varying electric circuit parameters are presented. The authors suggested contact‐free regulation of braking rheostat resistor for controlling braking force in rheostatic braking. A schematic diagram of harmonizing electrified railways and power system's upgrading aimed at ensuring power regeneration is also presented.