Traction Motor Research Articles

Comparative study of stator current-based and vibration-based methods for railway traction motor bearing cage fault diagnosis at high-speed condition

Traction motor’s rolling element bearings are one of the most critical components for the structural health monitoring of high-speed train vehicles. Most structural health monitoring techniques for railway rolling element bearings are using vibration signal. However, the vibration characteristic of cage defect is difficult to be transmitted to external monitoring point owing to the location of cage in bearing. Hence, the cage defect of Railway Traction Motor Bearing (RTMB) is usually difficult to be recognized with motor housing vibration acceleration signal. Considering Induction Motor (IM) itself a sensor, the mechanical imbalance of bearing cage defect can reflect in stator current through the motor gap magnetic field rather than a solid transmission path. A novel strategy with stator current for monitoring the traction motor bearing cage health status in High-Speed Train (HST) is proposed in this paper. This method requires no additional sensor in the practical application. To prove the strategy is feasible and more effective than vibration-based method for the cage fault diagnosis of RTMB, a comprehensive experiment investigation with a real railway traction motor of a HST is completed. Artificial cage defects are processed on bearings at both ends of the induction motor, respectively. Three high-speed (≥250 km/h) conditions are observed. The data analysis results show that vibration-based method is almost invalid at high-speed condition and the proposed current-based method is feasible and effective for the fault diagnosis of high-speed railway traction motor bearing cage.

Analysis of lithium-ion thermostabilization systems traction batteries of electric vehicles

Problem. The paper solves an important scientific and practical problem that allows to increase the competitive advantages of agricultural producers through the use of modern energy-efficient tractors with electric transmission. The control system of the traction electric drive is a component of the modern electric tractor of the fourth traction class which has become the most widespread and is intended for providing movement in the modes of various loading. The study of electric motors of a modern electric tractor of the fourth traction class is carried out. The electric motor is characterized by input and output parameters, internal parameters or state parameters, external influences. Methodology. The methods of theoretical basic electrical engineering have been developed in the production and calculation of circuits. Also classical methods of statistics of signals from ADC are used. Results. The technique of processing information from the current, voltage and temperature sensors using a mathematical apparatus without using harmonic analysis is presented. The hardware implementation of the proposed method allows the use of simplified computing tools. Originality. Complex analysis of the data obtained from the current, voltage and temperature sensors is carried out. During the analysis, the range of velocities with stable operation of the measurement system was determined. Based on the data obtained, it is concluded that the use of a horn antenna as a concentrator substantially eliminates lateral interference and extends the range of possible velocity measurements. It is shown that the level of sampling significantly affects the upper limit of the measurement speed. Practical value. It is shown that: As a result of the work, an important scientific and practical problem was solved, which allows to increase the energy efficiency of tractors through the use of tractors of the fourth traction class electric drive. To maintain the maximum energy efficiency of the traction electric drive of the tractor in the modes of various loads, its control system must include means of displaying the current state of the energy parameters of the power plant. The electrical equipment must include an on-board computer, which helps the driver to make the optimal tasks of work, according to preliminary calculations, as well as display the information needed on the route, the state of the vehicle, means of communication. communication of the car with the external environment, with the navigation system, etc. The on-board computer provides information to the touch screen with programmable virtual controls, and communicates with the driver's mobile systems. The study of electric motors of a fifth traction class electric tractor was carried out. As an object of motor control, it is characterized by input and output parameters, internal parameters or state parameters, external influences. An algorithm for selecting the parameters of the traction motor system has been developed and a circuit implementation of the control system has been offered.

Investigating the re-adhesion performance of locomotives with bogie frame suspension driving system

ABSTRACT The readhesion performance and driving system dynamics of locomotives with bogie frame suspension driving system were investigated. To investigate the driving system’s vibration characteristics in the adhesion saturation state and the influencing factors for locomotive’s readhesion performance, a train dynamic model was established. According to the simulation results, increasing the torsional stiffness of six-bar double hollow shaft coupling and adopting the traction motor with hard mechanical characteristics are beneficial for the locomotive’s readhesion performance. Besides, increasing the motor suspension stiffness within a certain range is advantageous. Moreover, resonance analysis was conducted, which indicated that the resonance of the driving system occurs if the natural frequency of wheelset’s longitudinal vibration is close to the rotary vibration natural frequency or its frequency doubling. Reasonable matching of primary longitudinal stiffness and six-bar double hollow shaft coupling stiffness is emphasized.

Research on Diagnosis and Prediction Method of Stator Interturn Short-Circuit Fault of Traction Motor

The traction motor (TM) is an essential part of the high-speed train, the health condition of which determines the quality and safety of the vehicle. Hence, this study proposed a novel approach to diagnosing and predicting the TM stator interturn short-circuit fault (SISCF). Based on the Park vector (PV) of the stator current, this method could overcome the interference of current sensor errors, null shift, and motor frequency fluctuations in the actual conditions. More specifically, Park’s transformation was used to obtain the PV of the stator current. Then, the PV was fitted to obtain the elliptical trajectory and its parameters from which the negative sequence component of the stator current could be calculated. Finally, the SISCF diagnosis and prediction method were realized by the magnitude and trend of the negative current as well as the inclination of the trajectory ellipse. Furthermore, the performance of the proposed method was validated by a simulation model and a series of experiments. The simulation results were consistent with the experimental results, supporting the validity and correctness of the method proposed in this study.

Potentials of Brushless Stator-Mounted Machines in Electric Vehicle Drives—A Literature Review

Brushless stator-mounted traction motors, which are new and emerging, have many potential applications in the electrified transport industry. Brushless stator-mounted machines (BSSMs), with the so-called flux modulation (FM) effects, use asynchronous field harmonics to realize energy conversion by altering the basic principle for conventional machine design which requires the stator and rotor to have the same pole number. The machines show promise of meeting the challenging requirements of electric vehicle (EV) traction motors. Therefore, in this paper, a review is undertaken on the state-of-the-art and potentials of the BSSMs for EV drives. The focus on BSSMs is due to their suitability for high-speed high torque density performance, as well as possessing suitable heat dissipation and flux weakening capabilities. The study is used to first rehash and discuss the design and excitation topologies, operating principles, and some emerging trends based on the basic BSSM variants, e.g., the doubly salient machine, flux reversal machine, and flux switching machine, while also undertaking a bibliometric synthesis on relevant studies highlighting the design and performance candidature of these niche BSSMs in EV applications, especially when compared to the well-developed Prius–IPM motor.

DETERMİNATİON OF TECHNICAL FEATURES OF THE NEW GENERATION ELECTRIC CARRIERS OF THE AZERBAIJANI RAILWAY

The main issues facing the locomotive economy were examined at the AzerbaijanRailways CJSC and the existing logistics base of the locomotive park was analyzed. It was expedientto purchase new locomotives showing the age structure of the Locomotive Park. For this purpose,the development of technical requirements for the production and commissioning of new locomotivesand motor vehicles, as well as the development of material and technical basis for the technicalmaintenance and repair system, as well as the development of advanced repair technology.The ATD uses the Az4A and Az8A electric locomotives from the new power circuits of staticconverters of electric motors in the main electric locomotives, and the functional circuits andenergetic diagrams of locomotives are installed. The use of asynchronous traction motors in newlocomotives is 1.5 times higher than the engine power compared to the constant dynamics of directcurrent; This allows you to increase 2.0 times, ATD can operate at rated power at all speeds, use lessnon-ferrous metals, use less environmentally friendly materials, reduce the complexity of repair andmaintenance. At the same time the number of locomotives decreases and the reliability and servicelife of locomotives increases. One of the main innovations in the new electric locomotives is thecorrect choice of structural schemes of traction transmission in the transmission of motion for thesupply of ATD.Functional diagrams and power schemes of locomotives are constructed using power supplycircuits of static converters of electric static electric locomotives in the main electric locomotivesusing electric locomotives Az4A and Az8A. The article analyzes the existing material and technicalbase of the locomotive fleet in the system of Azerbaijan Railways. The structure of the locomotive fleet and the tasks facing it are determined. The launch of international transport corridors and thegrowth of Azerbaijan's economic capacity have increased the demand for freight and passengertraffic. To this end, in connection with the purchase and commissioning of new locomotives andvehicles, the issues facing the Azerbaijani Railway will be resolved. As a result of the operation ofnew locomotives, the efficiency of the railway transport process will increase and train safety will beensured. In connection with the commissioning of new locomotives in the locomotive industry, thefollowing complex issues will be considered.

Comparison of Interior Permanent Magnet and Synchronous Homopolar Motors for a Mining Dump Truck Traction Drive Operated in Wide Constant Power Speed Range

Synchronous homopolar motors (SHMs) with an excitation winding located at the stator and a toothed salient pole rotor are a good alternative to motors traditionally used in traction applications such as induction motors or interior permanent magnet synchronous motors (IPMSM). This study presents the results of a theoretical comparison between an IPMSM and an SHM in a traction application with a constant power speed range of 1:10, which is specific to the mining truck drives, and with a rated power of 370 kW. The considered IPMSM and SHM have the same number of phases, poles and stator slots, and the same outer diameter of the stator lamination. The IPMSM design is optimized using the Nelder–Mead method. The main objectives of optimization are to minimize the average losses in the operating cycle and to limit the required power of the semiconductor inverter. The performance of the optimized IPMSM is compared with the previously obtained performance of the SHM optimized by the same method. Although the average losses in the operating cycle in the compared motors are approximately equal, the losses at high speed for the IPMSM are about two times greater than at low speed with maximum torque, which means that there is a need to intensify the IPMSM cooling system and there is deterioration of reliability. The advantage of the IPMSM is the reduction in the length of the active part by 30%. The advantage of the SHM is that there is 4.6 times lower cost of active materials. In addition, the SHM is more reliable than the IPMSM, as there is no risk of overheating, demagnetization or degradation of permanent magnets over time.

Derivation of Dynamic Model of Two-Input-Two-Output Torque Difference Amplification Motor Drive System and Independent Left-and-Right Wheel Control with Decoupling Compensator

A torque vectoring differential (TVD) enhances the cornering performance by generating a torque difference between the left and right wheels. For electrified vehicles, a TVD with a two-motor-torque difference amplification mechanism (TDA-TVD) is proposed, and it generates a greater torque difference than an Individual-wheel-drive (IWD) system under the same power output from the traction motors. However, owing to the complex gear reduction system including planetary gears and driveshafts, TDA-TVD has problems with the vibration of both the driveshaft torque and the yaw rate while cornering. To deal with these problems, a detailed dynamic model of TDA-TVD is first derived in this study. Secondly, a decoupling compensator is designed to achieve independent drive for the left and right wheels so that any motor drive algorithm designed for IWD systems can be applied. Thirdly, a vibration suppression controller is designed. Then, simulations and experimental evaluations using a real vehicle with the TDA-TVD are performed. The experimental results show the effectiveness of the vibration suppression of driveshafts and yaw rate.

Improvement of the model of an asynchronous traction motor of an electric locomotive by taking into account power losses

Wydawnictwo SIGMA-NOT wydaje czasopisma fachowe informujące swoich czytelników o najnowszych osiągnięciach naukowych i nowoczesnych rozwiązaniach technicznych w Polsce i na świecie, popularyzuje problemy techniczne oraz poszerza wiedzę i kulturę techniczną.

Diagnostics of traction motor of 1DT.003.11 type of electric train EP3D by modeling fuzzy linguistic parameters in matlab and fuzzy tech environment

The article presents the results of research in the field of diagnostics of a traction electric motor of the 1DT.003.11 type of the alternating current electric train of the EP3D series by simulating emergency modes of functioning of the fuzzy logic of a modular dynamical neural network. It is proposed to solve the problems of assessing the reliability of traction electric motors in railway transport with an increased service life using simulation modeling of the ANFIS modular neural network in the MATLAB package. The result of modeling the statistical diagnostic parameters of the traction motor is an assessment of the change in the linguistic coefficients of the residual life of the traction motor of the EP3D electric train and recommendations for the maintenance of traction electric motors, depending on their technical condition at the current time of operation.

Optimizing geometric parameters for the rotor of a traction synchronous reluctance motor assisted by partitioned permanent magnets

This paper considers partitioning parameters and the mutual arrangement of magnets in the rotor of the traction synchronous-jet engine with permanent partitioned magnets. The synthesis of geometrical parameters for the rotor of a synchronous reluctance motor with partitioned permanent magnets was proposed on the basis of solving the problem of conditional optimization. To solve the synthesis problem, a mathematical model has been built to determine the electromagnetic momentum of a synchronous reluctance motor with partitioned permanent magnets. It is based on the calculation of the electromagnetic momentum of the engine employing the results of a finite-element analysis of the magnetic field in the flat-parallel statement of the problem. The model is implemented in the finite-element analysis FEMM environment and makes it possible to determine the electromagnetic momentum of the engine with a variety of partitioning of permanent magnets. As an analysis problem, it is proposed to use a mathematical model of the magnetic field of the engine. The problem of conditional optimization of the rotor of a synchronous reluctance motor was stated according to the geometric criteria of the rotor. Restrictions are set on geometric, strength indicators, as well as on the level of electromagnetic momentum. The chosen optimization method is the Nelder-Mead method. Based on the results of solving the problem of synthesizing parameters for the partitioned rotor of the traction motor of trolleybus wheels, it was established that the volume of permanent magnets was reduced by 2.27 times compared to the base structure; their optimal geometric dimensions were determined (5 mm, 5.2 mm, and 5 mm), as well as the distance between them, 17.8 mm and 15.3 mm, and the engine load angle, which is 121.12 electrical degrees. Based on the results of solving the problem of synthesizing parameters for the partitioned rotor of a trolleybus traction synchronous reluctance motor, its optimal geometric parameters have been determined

All-SiC Traction Converter for Light Rail Transportation Systems: Design Methodology and Development of 165 kVA Prototype

The design and development of a high-performance 165 kVA, 750 V DC all-silicon carbide (SiC) traction converter for new generation light rail transportation systems (LRTSs) are described. In the design of the traction motor drive, the efficiency of the overall system is maximized and the line current harmonic content of the traction motor is minimized. A complete mathematical model of the physical system is derived to carry out real-time simulations and proper control of the LRTS on a real rail track. The electrical and thermal performances of traction-type SiC power MOSFET modules are compared with those of alternative hybrid and Si-IGBT modules for various switching frequencies. The implementation of the developed system is also described. The performance of the resulting system is verified experimentally on a full-scale physical simulator as well as for various track conditions. Very promising results for the next generation railway traction motor drives have been obtained in terms of performance criteria, such as very high efficiency, low harmonic distortion of the motor line current, low cooling requirement, relatively high switching frequency, and hence, superior controller performance. The effects of the SiC power MOSFET operation on the insulation of the available traction motors are also examined experimentally. This paper is accompanied by a video demonstrating the experimental work.

Technical Review of Traction Drive Systems for Light Railways

Due to environmental concerns, governments around the world are taking measures to decarbonise railway transport by replacing diesel traction systems with cleaner alternatives. While the electrification of railway systems is spreading rapidly, it is unlikely that all routes will be electrified as the volume of passengers will not justify the high infrastructure costs. Therefore, it is expected that, for several lines, a combination of hydrogen and electric traction will be used, with the latter partly provided by fixed infrastructure and partly by batteries. Railway traction drives will then need to change to accommodate these new types of power supply. A detailed review of the available traction motors and drives is provided with this review, given application to the new hybrid-electric systems. In particular, permanent magnet synchronous motors with multiphase windings are evaluated in comparison with traditional three-phase machines. Additionally, low and medium-voltage multisource power converters have been reviewed, taking into account the introduction of wide band-gap semiconductor devices.

Damage mechanism of crown spring for the EMU traction Motor’s connector

The electrical connector of the traction motor is an important device to ensure the stable operation of the electronic system of the EMU. Damage to the crown spring inside the connector will cause the traction motor to lose power supply. In this work, the damage morphology, composition and damage depth of the crown spring damage area were systematically analyzed using macroscopic and microscopic analysis equipment.Results show that the coating of the slightly damaged reeds was oxidized. Moderately damaged reeds have severe mechanical wear that caused the coating to disappear. Severely damaged reeds are caused by the combined action of mechanical wear, electrical wear and oxidative wear. At this stage, the connector joint heats up rapidly, which causes the crown spring to melt. The results show that the failure of the crown spring is the result of the combined effect of mechanical wear, electrical wear, and oxidative wear.

Analysis on characteristic of 3.3‐kV full SiC device and railway traction converter design

With the rapid development of wide-band gap semiconductor chip and package technologies, the voltage class of commercial silicon carbide (SiC) device is gradually improved. This paper concentrates on the latest 3.3-kV full SiC-based metal oxide semiconductor field-effect transistor (MOSFET) device and its application in railway traction. First, compared with the Si-based insulated-gate bipolar transistor (IGBT), the SiC-based MOSFET shows lower switching loss but weaker short-circuit capacity. Second, in the railway traction application, the SiC-based MOSFET with high switching frequency could reduce the inverter loss, the harmonic loss and the noise of traction motor. Third, a well-designed filter is necessary between the inverter and the motor to prevent the motor from terminal overvoltage and insulation problem, which are resulted from long cable and high dv/dt. Finally, a full-SiC railway traction inverter prototype is built and tested, and shows obvious advantages on miniaturization and lightweight.

Quantitative fatigue evaluation of complex welded connections and application in a train traction motor frame component

Welded connections are common in rail vehicle structures and associated equipment. It is well known that fatigue behaviors of welded structure are controlled by fatigue capability of welded joints. Although there exists numerous joint design guidance in Codes and Standards as well as best practices, they are largely empirical and difficult to apply in fatigue assessment of complex joints. In this paper, we adopt a mesh-insensitive structural stress method recently stipulated by ASME Code for fatigue evaluation of pressure vessels and piping components. Starting with stress concentration evaluation of two typical, but complex welded connections of relevance to some rail vehicle structures, we examine how the joint design principle inferred from the two examples can be effectively applied to an actual traction motor frame design and its effective fatigue improvement method. The experimental validation process is also presented for the proposed fatigue improvement technique.

Bidirectional DC-DC Converter for Electric Vehicle

The present work aims at designing and modelling of a bidirectional DC DC converter for driving a Permanent Magnet DC (PMDC) motor for Hybrid Electric Vehicle (HEV) and Electric Bikes (EV) application. Permanent Magnet Brushed DC (PMBDC) motors and Permanent Magnet Brushless DC (PMBLDC) motors are the most popular options that are used for the integration of an electric bicycle and bikes. But despite of the simple controllers and low cost of the PMDC motor its lower efficiency sets it back in choice in the present scenario as compared to the BLDC motors. The present design aims at improving the efficiency of the PMDC motor traction drive system by the incorporation of the bidirectional DC DC converter between the electrical source and the traction motor which in addition to its primary function of providing the traction energy, also facilitates the energy regeneration during braking (in the case of HEV and EV) and during the motion along down the slope(in case of a pedalled electric bicycle).

Optimization of powered wheels for commercial aircraft and design of test scheme

Electric landing gear drives equipped with traction motors are able to power the wheels of single-aisle commercial aircraft to provide the capability of taxiing on the ground. The powered wheels are utilized to solve the problems of low engine efficiency, high fuel consumption and high pollution of the aircraft during the taxiing process. The powered wheel electric drive system consists of an electric traction motor, a set of planetary gear assembly, and a wheel. This paper optimizes the parameters of the planetary gear assembly of the electric drive system to improve the outputted torque of the powered wheel. After that, two test schemes are designed for the powered wheel electric drive system to measure its torque. These two test schemes use moment of inertia and resistance loading to replace the actual vertical load of the aircraft applied on the powered wheel during the taxiing process. The first scheme uses the mass block to simulate the mass of the general aircraft, whereas the second scheme uses a flywheel with a variable moment of inertia to simulate the mass of large commercial aircraft.

T-Type Multi-Inverter Application for Traction Motor Control

The structure and principle of the T-type 3-level reverse voltage source that will be fed to three-phase induction motors will be presented in this study. The implementation of Space Vector Pulse Width Modulation (SVPWM) and the math models of the induction motor, the stator currents, and the speed controller design of the electric traction drive system based on Field-Oriented Control (FOC) will be also shown. This three-level T-type inverter in the FOC structure decreases Total Harmonic Distortion (THD) more than the previous two-level inverters. By combining the FOC control structure with the T-type 3-level inverter, the speed and torque responses necessary for railway traction motor load were improved. Finally, Matlab/Simulink will be used to demonstrate the correctness of the T-Type multi-level inverter theory.

Mitigation of Circulating Bearing Current in Induction Motor Drive Using Modified ANN Based MRAS for Traction Application

Induction motors are popularly used in various applications because of the proposed modest construction, substantiated process, and limited size of specific power. The traditional AC traction drives are experimentally analyzed. There is a high circulating current due to the high Common-Mode Voltage (CMV). The high Circulating Bearing Current (CBC) is a major problem in conventional two-level voltage source inverter fed parallel-connected sensor-based induction motors for traction applications. A sensorless method is well known for shrinking costs and enhancing the reliability of an induction motor drive. The modified artificial neural network-based model reference adaptive system is designed to realize speed estimation methods for the sensorless drive. Four dissimilar multilevel inverter network topologies are being implemented to reduce CBC in the proposed sensorless traction motor drives. The multilevel inverter types are T-bridge, Neutral Point Clamped Inverter (NPC), cascaded H-bridge, and modified reduced switch topologies. The four methods are compared, and the best method has been identified in terms of 80% less CMV compared to the conventional one. The modified cascaded H-bridge inverter reduces the CBC of the proposed artificial neural network-based parallel connected induction motor; it is 50% compared to the conventional method. The CBC of the modified method is analyzed and associated with the traditional method. Finally, the parallel-connected induction motor traction drive hardware is implemented, and the performance is analyzed.