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ABSTRACT This study presents the development of a small electric vehicle (EV) traction drive motor using Fe‐based amorphous laminated cores that can be mass produced. The following innovative technologies are developed to realize the amorphous laminated core: (1) production technology for thicker amorphous alloy foils to reduce the number of machining operations and (2) punching press technology for amorphous alloy foils that improves the usability of the tool life and maintains quality. The interior permanent magnet synchronous motor (IPMSM) using the amorphous laminated core is designed to be compatible with a 4.5‐kW‐class small EV traction drive with high efficiency while satisfying the required torque characteristics. A prototype of the designed IPMSM was manufactured and evaluated. The test machine achieves a maximum efficiency of 98.7% and a wide range of efficiencies exceeding 97%. Additionally, the prototype motor exhibit improved efficiency in all operating points compared with a prototype manufactured using an electrical steel sheet. [ABSTRACT FROM AUTHOR]

Today, a promising direction in the development of the field of application of linear motors is their use in the construction of well pumps. This makes it possible to significantly increase the stroke of the working body and improve the efficiency of oil production compared to the traditionally used rod-well analog. When solving such a problem, a difficult issue is forecasting and ensuring the traction force during the working trajectory of the movement, which is what the research conducted in the work is aimed at. As the main result, the application of the grapho-analytical method in the calculations and modeling of the characteristics of linear motors with complex trajectories of motion is substantiated. In the course of calculations with its use, the possibility of a four-fold increase in the traction force with a general improvement in the static characteristics of the engine in a given range of movement at the permissible speed of the working body was proven. References 5, figures 6. [ABSTRACT FROM AUTHOR]

The traditional mechanical wheel has high carbon emission, complex drive system structure, serious power reduction in high altitude and low temperature environment, and high operating cost. Aiming at the driving system of a 100t mechanical transmission dump truck, the composition and characteristics of the driving system are studied. A scheme of drive system and control system including main traction transmission and auxiliary system was proposed. The main traction system used 793 kWh power battery as the power source, to drive a 680 kW main traction motor combining with DTC algorithm. The two inverter modules, DC/DC module and battery cooling unit of the auxiliary system respectively drove the hydraulic pump motor steering and lifting, provided power for the vehicle air conditioning and cooling fan, and provided heat dissipation power for the battery. Mine loading test such as braking and traction conversion, heavy-load uphill starting, heavy-load uphill driving, and heavy-load downhill electric braking, etc. were carried out under full load condition at an altitude of 5500 m and-30 °C. The operation performance was reliable and stable, the operating cost was reduced by 93%, the total running time was 4230 h, and the total running mileage was 4238 km. The structure of the driving system is simple, recovery of braking energy improves the energy efficiency of the system, reduces carbon emissions and promotes the development of green mines. [ABSTRACT FROM AUTHOR]

Electric trains are becoming increasingly popular due to their environmental protection and ability to transport a large number of passengers. Alongside this trend, traction motors for electric trains have become diverse thanks to the rapid development of power electronics. Among them, the permanent magnet synchronous motor (PMSM) stands out with advantages such as high efficiency, high torque-to-current ratio, and compactness compared to other motors of the same power, making it the top choice. However, PMSM motors are nonlinear objects, so the nonlinear control technique of sliding mode control has been applied to the speed loop in this paper. Additionally, electric trains' inertial torque and load torque vary due to changes in the number of passengers during peak and off-peak hours and weather conditions. Therefore, this paper introduces two adaptive coefficients to account for these variations. Simulation results show that the sliding mode control technique for the speed loop circuit provides a faster and more accurate speed response. Meanwhile, the two parameters also adapt to the inertial and load torque variations. This ensures the safety and efficiency of the electric train system, contributing to the advantages of this mode of transportation. [ABSTRACT FROM AUTHOR]

For an electric locomotive traction motor, it is necessary to maintain relatively low vibration and noise due to the higher design standards. By using effective motor control strategies and implementing current harmonic suppression schemes, motor efficiency and vibration and noise suppression can be effectively improved. This study investigates the current harmonic suppression strategy for permanent magnet synchronous motors by (1) constructing a mathematical model of the permanent magnet motor to explore the sources of low-order harmonics currents such as fifth and seventh harmonics, as well as high-order harmonics at switch frequencies and their multiples, and analyzing the electromagnetic force characteristics generated by the current, and (2) establishing a vector control system for the permanent magnet motor. To suppress the fifth and seventh harmonic components in the current, a resonance controller is constructed, which utilizes the parallel connection of a resonator and PI controller to achieve low-order harmonic suppression. The factors affecting the effectiveness of the resonance controller's suppression are also analyzed. The experiments are conducted, and the current harmonic suppression scheme constructed in this study can effectively reduce the harmonics in the current, thereby reducing motor vibration and noise. [ABSTRACT FROM AUTHOR]

As a part of last-mile transportation, electric three-wheelers, popularly known as trikes, are considered as an important aspect of the future of the auto industry. The appropriate choice of electric traction motor drive is imperative to the design of an electric motor power train. In this paper, six main types of sinusoidal-fed electric motor power trains--Ferrite-Assisted Synchronous Reluctance Motor (FASRM), Synchronous Reluctance Motor (SyncRelM), Ferrite-based Spoke motor, Ferrite-based Surface-Mounted Permanent Magnet Synchronous Motor (SMPMSM), Wound-Field Synchronous Motor (WFSM), and Induction Motor (IM)--are compared for their performance in electric trike applications. The permanent magnet machines presented here utilize ferrite magnets, in line with the recent trend of not using rare-earth magnets. The comprehensive comparative analysis establishes that SyncRelM, FASRM, and Spoke motors are superior in terms of overall electromagnetic, thermal, and vibration performance. This paper also focuses on an optimal design of the FASRM due to its high torque density, lower torque ripple, and minimal use of ferrite magnets. A Design of Experiments (DoE)-based statistical analysis tool is used to identify the key parameters needed for robust motor performance in the optimization step. Furthermore, an Extreme Learning Machine (ELM)-based interpolation technique is employed for estimating the performance parameters during each step of the optimization routine. A 1.2 kW FASR motor prototype is developed and tested. A comparison of Finite-Element-Analysis-based modeling results is presented along with Indian drive-cycle results for the FASRM for trike application. [ABSTRACT FROM AUTHOR]

In modern electric traction, direct current traction motors have been replaced with asynchronous motors with a short-circuited rotor. The justification is that asynchronous motors are more reliable, cheaper, and have smaller weights and dimensions, so they are more sustainable. In order to start and adjust the speed required in traction, these motors are powered from the contact line using a transformer and a static voltage and frequency converter. As a result, you can use green electricity produced with wind power plants or solar energy converted with photovoltaic panels, increasing sustainability because the consumption of traditional fuels is reduced. This paper presents various simulations emphasizing the negative effects of the distorting regime, with concrete results. The quality of the simulations carried out is increased by using a mathematical model, which uses the variable parameters of the motor dependent on the modulation of the current and the magnetic saturation. In modern 1500 kW electric locomotives, the traction motors are powered by static converters, which means an increase in losses when operating at nominal load on the motors by 38.7 kW and 217.8 kVAR compared to the sinusoidal three-phase power supply. Thus, the research carried out provides qualitatively and quantitatively correct simulations of the non-sinusoidal regime related to the asynchronous traction motor in order to increase the sustainability of this traction system. [ABSTRACT FROM AUTHOR]

The traction motors installed on the bogie frame of high-speed trains are of adverse effect on the bogie hunting stability. Utilising the elastic-suspended motors as dynamic vibration absorbers can increase the hunting critical speed. However, the vibration and dynamic stress of the motor system will be aggravated compared to the rigid motor suspension. In this work, the hunting stability and dynamic stress of a high-speed bogie with elastic-suspended motors are studied. Firstly, the DVA mechanism of hunting stability for a bogie with elastic-suspended motors is conducted by the eigenvalue method. Increasing the critical speed by the elastic motor suspension will sacrifice the motor vibrations and stresses. Secondly, the rigid-flexible coupled dynamic model of the vehicle and motor system is developed to give insight into the consequent effects on dynamic stress. Finally, some countermeasures, e.g. wheel-rail conicity control and motor suspension optimisation, are proposed to suppress the dynamic stress of the motor hanger system. One effective manner to suppress the dynamic stress of the motor hanger system is to improve the hunting stability by limiting the wheel-rail conicity. Another one is to lower the lateral stiffness of the motor suspension and increase the damping ratio of the motor damper. [ABSTRACT FROM AUTHOR]

Copyright of Smart Rail Transit is the property of Smart Rail Transit Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the growing demand and projected shortage of rare earth elements in the near future, the urgent task of developing energy-efficient electrical equipment with less dependence on rare earth magnets has become paramount. The use of permanent magnet-assisted synchronous reluctance motors (PMaSynRMs), which reduce the consumption of rare earth magnets, can help solve this problem. This article presents a theoretical analysis of the characteristics of PMaSynRM in a subway train drive. Options with rare earth and ferrite magnets are considered. Optimization of the motor designs considering the train movement cycle is carried out using the Nelder-Mead method. Characteristics of the motors, such as losses, torque ripple, and inverter power rating, as well as the mass and cost of active materials, are compared. [ABSTRACT FROM AUTHOR]

This paper proposes an observer-based hierarchical distributed model predictive control (MPC) strategy for ensuring speed consistency in multi-linear motor traction systems. First, a communication topology is considered to ensure information exchange. Secondly, the control architecture of each agent is divided into upper layers and lower layers. The upper layer utilizes a distributed MPC method to track the leader's speed. The lower layer uses a decentralized MPC method to track the command signals sent by its upper layer controller. In addition, to eliminate the negative impact of disturbance, a nonlinear disturbance observer is designed. We then prove the asymptotic stability of the entire system by properly designing the Lyapunov equation. Finally, the feasibility of the proposed strategy is verified based on several simulations. • A hierarchical distributed model predictive control for multi-linear motor traction systems is introduced. • The nonlinear disturbance observers are adopted to improve the system's robustness. • A strict proof is constructed for the Lyapunov criterion of asymptotic stability. [ABSTRACT FROM AUTHOR]

Interior permanent magnet synchronous machines (IPMSMs) are widely used as traction motors in the electric drive-train because of their high torque-per-ampere characteristics and potential for wide field weakening operation to expand the constant power range. The paper aims to introduce the most important equations to calculate the operating trajectories of an IPMSM for optimal control. The main contribution is that the optimal operating trajectories are calculated by a feedforward, Newton–Raphson method-based searching algorithm that considers the iron loss resistance of IPMSMs. Steady-state calculations and dynamic simulation results prove the theoretical findings. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Hebei University of Science & Technology is the property of Hebei University of Science & Technology, Journal of Hebei University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The magnet-less switched reluctance motor (SRM) speed-torque characteristics are ideally suited for traction motor drive characteristics and its advantage to minimize the overall cost of on-road EVs. The main drawbacks are torque and flux ripple, which have produced high in low-speed operation. However, the emerging direct torque control (DTC) operated magnitude flux and torque estimation with voltage vectors (VVs) gives high torque ripples due to the selection of effective switching states and sector partition accuracy. On the other hand, the existing model predictive control (MPC) with multiple objective and optimization weighting factors produces high torque ripples due to the system dynamics and constraints. Therefore, existing DTC and MPC can result in high torque ripples. This paper proposed a finite set (FS)-MPC with a single cost function objective without weighting factor: the predicted torque considered to evaluate VVs to minimize the ripples further. The selected optimal VV minimizes the SRM drive torque and flux ripples in steady and dynamic state behaviour. The classical DTC and proposed model were developed, and simulation results were verified using MATLAB/Simulink. The proposed model operated in SRM drives experimental results to prove the effective minimization of torque and flux ripples compared to the existing DTC. [ABSTRACT FROM AUTHOR]

In this study, we present a new mixed cooling system that combines internal oil with water-cooling, and the effective temperature control of the motor resulted in long-term stable operating conditions. Mass, momentum, and energy equations were obtained by adopting the volume of fluid and moving reference frame methods for an in-depth heat transfer analysis of motor cooling systems. In addition, various cooling systems, such as churning and drop methods were carefully selected by considering the maximum temperature and heat transfer path of the advanced motor. To ensure the reliability of the computational model, the internal thermal resistance of the motor was adjusted based on the analysis results of the reference case. The churning effect facilitated heat transfer through the air gap, thus minimizing the local temperature difference between the rotor magnets and stator coils. The drop effect directly cooled the end coil, thereby resulting in a high cooling efficiency. [ABSTRACT FROM AUTHOR]

Permanent magnet synchronous motors (PMSMs) have been employed in the direct drive traction system of locomotives as the traction motor. Due to the unique traction structure of the direct drive system, complicated excitations such as track irregularity and harmonic torque have a direct effect on the dynamic performance of the motor and other key components of the locomotive. However, the dynamic characteristics under this effect and influencing law have not been revealed completely. This paper develops a dynamics model of a locomotive with direct drive traction system which enables considering the electromechanical coupling effect between the vehicle subsystem and the PMSM control subsystem. The nonlinearity of the wheel–rail contact and flexible transmission coupling are taken into account in this model. By using this model, the dynamic responses of the locomotive are analysed under electrical and mechanical excitations. The results indicate that the harmonic components in the electrical subsystem have considerable effects on the key components of the locomotive, such as the wheelsets and the motors. It can also cause resonance in the mechanical transmission system when the locomotive is operating at a specific speed. This resonance can be eliminated by adopting the harmonic suppression algorithm. [ABSTRACT FROM AUTHOR]

Traction motor bearings, as a crucial component of subway trains, play a pivotal role in ensuring the safety of train operations. Therefore, intelligent diagnosis of train bearings holds significant importance. However, due to the complex and dynamic nature of bearing conditions coupled with limited fault data availability, traditional diagnostic methods fail to yield satisfactory results. To address this issue, we propose an improved metrics-based meta-learning approach for accurate few-shot cross-domain fault diagnosis of train bearings. Firstly, we introduce a 1D-signal channel attention mechanism that effectively extracts latent features and enhances recognition accuracy. Secondly, by incorporating the Adabound algorithm into our model framework, we further enhance its classification performance. Finally, through several case studies, we demonstrate the effectiveness of our proposed method in comparison to other approaches within similar settings. [ABSTRACT FROM AUTHOR]

Due to their excellent mechanical strength, corrosion resistance, and ease of processing, carbon fiber and carbon-fiber-reinforced plastics are finding wide application in diverse fields, including aerospace, industry, and automobiles. This research explores the feasibility of integrating carbon fiber solutions into the rotors of 85-kilowatt electric vehicle interior permanent magnet synchronous motors. Two novel configurations are proposed: a carbon fiber wire-wound rotor and a carbon fiber injection-molded rotor. A finite element analysis compares the performance of these models against a basic designed rotor, considering factors like no-load back electromotive force, no-load voltage harmonics, cogging torque, load torque, torque ripple, efficiency, and manufacturing cost. Additionally, a comprehensive analysis of system efficiency and energy loss based on hypothetical electric vehicle parameters is presented. Finally, mechanical strength simulations assess the feasibility of the proposed carbon fiber composite rotor designs. [ABSTRACT FROM AUTHOR]

The object of research is the process of dynamic balancing of rotors on a balancing machine in the process of restoring electric machines. The work is aimed at improving the quality of balancing rotors in the process of major repairs of traction electric motors for electric trains. The problem addressed was the quality of balancing the rotors of electric machines on stationary balancing machines. According to the conventional balancing technology, the rotor to be balanced is mounted on the supports of the balancing machine with support surfaces that usually have mechanical defects. These defects cannot be eliminated by machining due to the peculiarities of rotor repair technology. Theoretical and experimental studies of the effect of damage to the rotor support surfaces on the balancing parameters have been carried out. It has been proven that the properties of the bearing surfaces of the rotor during its balancing on a balancing machine significantly affect the results of determining the imbalance. At the same time, the difference in the mass values of balancing loads can reach 25 %. This is because damage to the bearing surfaces of the rotor generates false signals unrelated to the imbalance. In order to increase the accuracy of determining the mass of balancing loads during rotor balancing, it is proposed to improve the technological process of balancing. The improvement involves the inclusion of a frequency filter in the signal conversion chain of acceleration sensors. The filter is designed to separate signals with a frequency greater than the rotational frequency of the rotor. A condition for the practical application of the research results is the expediency of introducing a frequency filter of signals of acceleration sensors with a threshold frequency of filtering signals that exceeds the rotational frequency of the rotor into the schematic diagram of the balancing machine. [ABSTRACT FROM AUTHOR]

Induction motors make up approximately 80% of the electric motors in the railway sector due to their robustness, high efficiency, and low maintenance cost. Nevertheless, these motors are subject to failures which can lead to costly downtime and service interruptions. In recent years, there has been a growing interest in developing fault diagnosis systems for railway traction motors using advanced non-invasive detection and data analysis techniques. Implementing these methods in railway applications can prove challenging due to variable speed and low-load operating conditions, as well as the use of inverter-fed motor drives. This comprehensive review paper summarizes general methods of fault diagnosis for induction machines. It details the faults seen in induction motors, the most relevant signals measured for fault detection, the signal processing techniques for fault extraction as well as some classification algorithms for diagnosis purposes. By giving the advantages and drawbacks of each technique, it helps select the appropriate method that could address the challenges of railway applications. [ABSTRACT FROM AUTHOR]

AC-DC-AC traction transmission system provides power for high-speed train and is one of the key technologies for rail transit. The rectifier part adopts a four-quadrant rectifier, which has advantages such as high power factor, low harmonic content, and energy feedback. However, due to the power characteristics of single-phase power supply in electrified railways, there is a double power frequency fluctuation in the DC link voltage of the traction transmission system. In addition, the current output controlled by the inverter contains higher-order harmonics. In order to study the influence of harmonic components on the traction motor of high-speed train, an AC-DC-AC traction system simulation model for high-speed train was established. The results show that after LC filtering, at the condition that the stator current frequency is close to 100Hz, the motor stator current still undergoes distortion, but the effect on torque is not significant. When the LC filter fails, the torque ripple caused by 100Hz is very significant. It is recommended to consider this in the fault detection system of the traction transmission system. During train operation, the torque ripple at frequency of 6-times motor stator current is prominent, and this frequency also exists in the voltage and current of the DC link. [ABSTRACT FROM AUTHOR]

This paper deals with the phenomenon of torsion oscillations in railway vehicle drive systems. The main goal is to reduce the risk of presence of torsional oscillations in wheelset drive, eventually to propose systems to effectively identify and eliminate torsional oscillations of wheelsets. Therefore, a simulation wheelset drive model including a detailed model of the asynchronous traction motor control was built. The results of computer simulations show that the torsional oscillations can be effectively eliminated by avoiding the resonance states between the excitation frequencies given by pulse width modulation of the inverter and the eigenfrequencies of the mechanical part of the drive. Furthermore, it was found that the presence of torsional oscillations of the wheels can be detected based on the traction motor current ripple. The wheelset drive model was subsequently implemented in a simulation model of a four-axle locomotive. A new algorithm of an anti-slip protection system that utilizes motor currents was implemented in the model. Simulations show that such an anti-slip protection system can prevent the occurrence of undesired large amplitude of wheelset torsional oscillations. The models and simulation results are presented in detail in the paper. [ABSTRACT FROM AUTHOR]

Maintaining optimal temperatures in the critical parts of an induction traction motor is crucial for railway propulsion systems. A reduced-order lumped-parameter thermal network (LPTN) model enables computably inexpensive, accurate temperature estimation; however, it requires empirically based parameter estimation exercises. The calibration process is typically performed in labs in a controlled experimental setting, which is associated with a lot of supervised human efforts. However, the exploration of machine learning (ML) techniques in varied domains has enabled the model parameterization in the drive system outside the laboratory settings. This paper presents an innovative use of a multi-agent reinforcement learning (MARL) approach for the parametrization of an LPTN model. First, a set of reinforcement learning agents are trained to estimate the optimized thermal parameters using the simulated data in several driving cycles (DCs). The selection of a reinforcement learning agent and the level of neurons in the RL model is made based on variability of the driving cycle data. Furthermore, transfer learning is performed on a new driving cycle data collected on the measurement setup. Statistical analysis and clustering techniques are proposed for the selection of an RL agent that has been pre-trained on the historical data. It is established that by synergizing within reinforcement learning techniques, it is possible to refine and adjust the RL learning models to effectively capture the complexities of thermal dynamics. The proposed MARL framework shows its capability to accurately reflect the motor's thermal behavior under various driving conditions. The transfer learning usage in the proposed approach could yield significant improvement in the accuracy of temperature prediction in the new driving cycles data. This approach is proposed with the aim of developing more adaptive and efficient thermal management strategies for railway propulsion systems. [ABSTRACT FROM AUTHOR]

Tractor motors always operate in the speed region higher than rated speed, but is limited to the module of the stator current, stator voltage vectors. Additionally, mathematical model of traction motor has shown nonlinearity through the product of the state variables isd, isq with the input variable isd, isq with the input variable ωs:ωsisq, ωsisd. Therefore, this paper focuses on the study of speed control of traction motors in weakening field region while optimizing torque control, and choosing the backstepping method in designing speed-flux controller in order to solve the nonlinear structure. The simulation results of the responses: speed, torque, power, and flux performed on MATLAB/Simulink software with parameters collected from metro Nhon-Hanoi Station, Vietnam have proven the correctness in theoretical research. [ABSTRACT FROM AUTHOR]

The utilization of renewable sources connected to a grid to reduce traction substation installation costs and electrified trains' operation energy is a highly promising solution in the electric transportation field. This study proposes a DC traction power supply system integrated with a solar energy system using a DC-DC boost converter and an active rectifier replacing a diode located at the traction substation. The active rectifier not only recovers regenerative braking energy when electric trains operate in braking mode but also transfers solar energy from the DC bus to the grid. With the characteristics of urban railway lines utilizing high-power traction motors and high-voltage DC bus, this paper presents the structure of the Modular Multilevel DC-DC boost converter in the solar energy system employing the Maximum Power Point Tracking (MPPT) algorithm, whereas the modular multilevel active rectifier utilizes the Voltage Oriented Control (VOC) algorithm with three loop circuits: phase-lock loop, current loop, and voltage loop. Simulation results in Matlab/Simulink with parameters collected from the Nhon-Hanoi station urban railway line in Vietnam demonstrate that the PV system produces almost 37% of the energy in the accelerating phase of electric trains. [ABSTRACT FROM AUTHOR]

With the development of new energy industries, the demand for the driving range and power quality of electric vehicle (EV) drive systems is growing rapidly. The drive motor is faced with the challenge of continuously improving power density and performance. This paper proposes a multiobjective optimization method for an interior permanent magnet synchronous motor for a traction drive (IPMSMTD). Based on the flat wire winding technology, the multiobjective optimization design of the IPMSMTD is carried out to improve the motor power density and high‐efficiency range, reduce the torque ripple, and suppress the electromagnetic vibration and noise. The structure and size equation of the IPMSMTD are described. The mathematical model considering iron losses is established, and the optimization objectives are determined. Based on the genetic algorithm, a multiobjective optimization mechanism of the magnetic pole structure is established. The operation performance of the motor is analyzed by the finite element simulation and efficiency map. In order to ensure the comprehensive operation index of the IPMSMTD, the vibration noise and modal analysis are carried out, which verifies the rationality of the designed motor and the optimization method. [ABSTRACT FROM AUTHOR]

A single type of sensor is susceptible to interference and limited degradation information can be extracted. Therefore, a multi-information fusion-based bearing remaining useful life prediction method using the dual-channel convolutional neural network (DCCNN) and the gated recurrent unit (GRU) is proposed. Firstly, vibration sensors are utilized as a basis for signal collection, while acoustic emission sensors are introduced as a complement to obtain more comprehensive degradation information. Secondly, the time domain, frequency domain and time-frequency domain features of the vibration signal and acoustic emission signal were extracted respectively to construct a comprehensive bearing degradation feature set. Third, multiple evaluation indicators are used to comprehensively evaluate the degradation features, and effective degradation features that are highly related to bearing degradation are selected for feature fusion. Subsequently, the DCCNN-GRU model was established, which captures and comprehensively utilizes different degradation feature information in each channel through the DCCNN network structure, and employs GRU to process the time relationships and dependencies in sequence data to solves the vanishing gradient problem. Finally, an experimental bearing test bench was constructed to collect data, and this data was used to experimentally validated the model and compared with other methods to demonstrate its feasibility and effectiveness. [ABSTRACT FROM AUTHOR]

The progression and refinement of traction electric motors play a pivotal role in the enhancement of vehicles. With constant advancements in power efficiency, diagnostic tools, and reliability, electric traction motors are becoming more economical in terms of operational costs. This article underscores the significance of methods used in assessing the technical proficiency of traction electric motors, coupled with their testing techniques. The vibration characteristics of these motors serve as a prime criterion in assessing their quality throughout their lifecycle – from design and manufacturing to operation. A groundbreaking proposition made in this article is the evaluation of electric traction motors' health based on their vibration acceleration within an expansive frequency range of 5 Hz to 10 kHz. This contrasts the conventional approach which focuses on vibration speed in a restricted frequency spectrum up to 1000 Hz, as outlined by current standards. Such permissible vibration classes are essential in ensuring the high-quality design, technical finesse, and dependability of traction electric motors. Exceeding these vibration thresholds can result in rapid wear and tear, diminishing the motor's reliability and lifespan. Hence, motors that surpass these permissible vibrations are not advised for vehicular use. Additionally, the article sheds light on requisite equipment controls for accurately gauging vibrations and noise levels in electric motors. Delving deeper into the nuances, the methods for mounting vibration transducers and electric motors on testing platforms are elucidated. These methods are pivotal in obliterating any hindrances that could impede the precise measurement of vibrations induced by an electric motor. [ABSTRACT FROM AUTHOR]

Interior permanent magnet synchronous motors (IPMSMs) are extensively used as traction motors today because of their exceptional torque, power density, and wide, constant power operating range. Under real-world usage, an IPMSM rotor undergoes varying electromagnetic, thermal, and mechanical loads. Under such conditions, fatigue life-based design criteria should be used over stress-based design criteria to ensure the structural integrity of the rotor. Moreover, the driving dynamics can change the rotor temperature continuously, which affects the electromagnetic, mechanical, and fatigue properties of the rotor material. This paper proposes a robust thermomechanical rotor fatigue simulation workflow considering significant loads acting on an IPMSM rotor and the temperature variation throughout a drive cycle. It discusses an accelerated fatigue life estimation approach based on the peak valley extraction method to reduce the simulation time significantly for the stress and fatigue analysis. Then, it presents a method for a stress-life curve generation for variable loading. It also presents a sensitivity study with a median S-N curve, and a 90% reliability and 95% confidence (R90C95) S-N curve. [ABSTRACT FROM AUTHOR]

Introduction. Power quality in an electric railway system pertains to the dependability, consistency, and purity of the electrical power provided to different components and systems within the railway infrastructure. Assessing power quality offers considerable opportunities to improve the efficiency of railway systems. Problem. Managing the flow of active and reactive power effectively, decreasing harmonic currents, and addressing the negative sequence component are all critical parts of improving power quality for electrified rail systems. As a result, flexible AC transmission systems are the major means of minimizing or decreasing these difficulties. Purpose. This study describes a half-bridge reactive power railway power conditioner (HB-RPC) with a novel Ynev balancing transformer. HB-RPC is made up of four switching devices and two DC capacitors and the compensator’s stability is determined by the operating voltage of the DC-link. Any variations or imbalances in the DC voltage might cause the compensator to operate in an unstable manner. Novelty. Of a novel balanced transformer with HB-RPC in a high-speed railway system with two scenarios. Methods. The study utilized MATLAB/Simulink software for simulation purposes. The system integrates a fuzzy logic controller (FLC) and a PI controller to optimize DC voltage, ensuring its constancy and balance, with the objective of improving the overall stability of the system. Results. The simulation outcomes illustrate the efficacy of the control approach. Through a comparison of results between scenarios (two and four trains) with the PI-based)HB-RPC and the FLC-based-HB-RPC, the system exhibits enhanced stability for the proposed railway system when employing the FLC)based-HB-RPC, compared to a controller based on PI. Practical value. The proposed configuration elucidates its role in enhancing both the dynamic performance of the system and the power quality of the three-phase rail traction chain. References 21, table 6, figures 2 [ABSTRACT FROM AUTHOR]

Batteries have been integral components in modern vehicles, initially powering starter motors and ensuring stable electrical conditions in various vehicle systems and later in energy sources of drive electric motors. Over time, their significance has grown exponentially with the advent of features such as "Start & Stop" systems, micro hybridization, and kinetic energy regeneration. This trend culminated in the emergence of hybrid and electric vehicles, where batteries are the energy source of the electric traction motors. The evolution of storage for vehicles has been driven by the need for larger autonomy, a higher number of cycles, lower self-discharge rates, enhanced performance in extreme temperatures, and greater electrical power extraction capacity. As these technologies have advanced, so have they the methods for their disposal, recovery, and recycling. However, one critical aspect often overlooked is the potential for battery reuse once they reach the end of their useful life. For each battery technology, specific regeneration methods have been developed, aiming to restore the battery to its initial performance state or something very close to it. This focus on regeneration holds significant economic implications, particularly for vehicles where batteries represent a substantial share of the overall cost, such as hybrid and electric vehicles. This paper conducts a comprehensive review of battery technologies employed in vehicles from their inception to the present day. Special attention is given to identifying common failures within these technologies. Additionally, the scientific literature and existing patents addressing regeneration methods are explored, shedding light on the promising avenues for extending the life and performance of automotive batteries. [ABSTRACT FROM AUTHOR]

Nowadays rare-earth magnets available in the market are limited, while demand for them is increasing, therefore development of electrical machines without magnets of this type becomes extremely important. Simultaneously, synchronous machines without magnets have poorer torque to weight and torque to volume characteristics compared to machines equipped with magnets. The compromised solution is usage of cheap ferrite magnets as a source of auxiliary machine flux. However, the most serious disadvantage of ferrite magnets is the possibility of unrecoverable demagnetization. In order to solve the abovementioned problem this paper proposes a novel design of ferrite assisted synchronous homopolar motor (FASHM), which is equipped with magnets of special shape, resulting in higher resistivity to demagnetization. This research provides theoretical analysis of working characteristics of the motor of proposed design, developed for subway train, and compares them with the characteristics of the motor without the proposed design features. The FEM modelling demonstrates that the proposed design is superior to the existing solution. It has higher resistivity to unrecoverable demagnetization of the ferrite magnets, consumed current and power loss are decreased, the mass of motor and price of the magnets are reduced.