Siglo Cero

Wheel flat can seriously affect the wheel–rail contact performance and cause impact vibrations, which significantly threaten the safe operation of railway vehicles. It is crucial to accurately assess the effects of wheel flats on the wheel–rail contact performance and the vibration impact on the traction drive system. However, studies related to wheel flats have focused on the mechanical part and have yet to fully consider the electrical and mechanical parts of the entire traction drive system. Therefore, this paper first builds an electromechanical coupling model based on the electric traction drive system and the locomotive-track coupling dynamics model. Then, based on this model, the impact of the wheel flat on the electrical and mechanical parts of the traction drive system under different flat lengths, different flat depths, and different vehicle speeds was analyzed. The results indicate that with the increasing depth of the flat spot, the wheel–rail dynamic response, motor rotor speed, and motor torque exhibit more significant fluctuations. Additionally, as the locomotive speed increases, the impact of the flat on the wheel–rail contact performance intensifies. Wheel flats can excite the 1st bending mode of the wheelset, resulting in vibration shocks at 90 Hz.

This article proposes a dual independent rotor axial flux induction motor (DIR-AFIM) with two degrees of freedom as a propulsion motor for an electric vehicle (EV). The performance of this motor in different operating conditions of the vehicle is discussed and investigated. This motor has two rotors that are mechanically independent of each other, providing driving force for the EV separately and enabling the removal of any mechanical or electrical differential. The propulsion motor can play the role of differential and also reduce the cost and complexity of the entire propulsion system in some extent. The finite element modeling of the proposed motor has been performed and the performance characteristics have been evaluated in three operating scenarios: flat path, sloped path, and turning path, taking into account the dynamics of the vehicle. Additionally, the accuracy of the simulations and modeling has been confirmed by performing some practical tests on the prototype machine. The results show that the simulations and measurements are in good agreement and the proposed propulsion system can be a suitable option for lightweight electric vehicles.

The wireless charging for electric vehicle is getting popular due to the absence of sophisticated cable connection and associated issues with the actuators in field for connected charging. The major challenges in inductive power transfer (IPT) systems are the control of the resonance converter and synchronisation in communications with the vehicle and power supply. In IPT system, the dynamic nature of load as well as system demands extra care for the existing charging architectures. This work proposes a unique control algorithm to charge the Li-ion battery under coupling coefficient and load variations. The developed control algorithm is validated in MATLAB simscape platform. Further, the control logic is validated using the Texas C2000 Delfino controller in 1 kW IPT system. The developed control logic would ensure proper frequency of operation as well as the constant voltage and constant current control.

As the reduction of greenhouse gas emissions becomes crucial, electric vehicles (EVs) are expected to enter the market extensively in the coming years. The efficiency of the electrical motor used in EVs plays a significant role in their overall performance. This paper explores the flux switching motor (FSM) and its applications in EVs. The FSM is compared to other electrical motors, highlighting its potential as a suitable choice for EV traction. Various configurations and techniques are reviewed to enhance the performance of FSMs, including magnetic materials, torque ripple alleviation, and magnetic flux weakening. The advantages and disadvantages of these methods are discussed, providing valuable insights for designing FSMs for EVs. Generally, EV traction requires high torque density and high power density electrical motor. To achieve these goals, high electric and magnetic loading must be considered in design stage of the motor. Application of the FSM may be one of the appropriate option. For many reasons, three-phase FSM is preferred. Considering the base speed of machine in the EV and high electric loading, the FSM with 12 stator teeth and 10 rotor teeth may be the most appropriate choice in which the stator core is oriented and rotor core is nonoriented iron. To enhance the torque density and applied flux weakening method, combination of Nd and Al–Ni–Co magnets is preferred.

This article presents a nonbridged isolated positive Cuk (NB-IPCuk) converter-based single-stage battery charging system (SSBCS). The architecture of the suggested charger ensures the intrinsic advantage of power quality improvement in discontinuous current conduction (DCC) mode at the supply mains. The suggested NB-IPCuk converter scheme has fewer components than other bridgeless/nonbridged Cuk converter schemes. This is because the NB-IPCuk converter is a partial integration of two Cuk converters. The usage of the Cuk converter garnishes the system with input and output inductances, which lessens supply current harmonic distortion and, thus supply terminal low pass filter requirement is eradicated. The advantages of the NB-IPCuk converter are the eradication of one inductor and multiple diodes (two back-feeding diodes), which are generally used in NB converter configurations. In place of two separate inductors, the NB-IPCuk converter uses a single secondary side output inductor. The usage of BL configuration of NB-IPCuk converter eradicates the bridge rectifier (BR) stage, and thus, the BR-associated losses also got eradicated. The NB-IPCuk converter also garnishes the system with electrical isolation which adds to the safety standards of the system. DCC mode operation of the NB-IPCuk converter is used in the present work. DCC mode requires lesser sensors in comparison to continuous current conduction mode. The abovementioned benefits of the NB-IPCuk converter make the SSBCS system cheaper, compact, and more efficient. The detailed stability analysis (Bode diagram and pole-zero map) and mathematics for the NB-IPCuk converter are also included in the paper. The prototype and MATLAB/Simulink model of NB-IPCuk converter-based SSBCS system with DCC mode control has been built, and results of both prototype and MATLAB/Simulink are deployed to verify SSBCS system’s performance during dynamic and steady-state conditions.

The power industry is embracing green energy solutions to meet growing demand along with advancement in its technological innovations. Among the myriad innovations, electric spring stands out as a cutting-edge technology, embracing the concept of smart load to intelligently manage power systems. Concurrently, the emergence of electric vehicles (EVs) has paved the way for a new branch of power networks in the transport system. Ingeniously combining these two trends, a smart charging mechanism has been developed through an EV charging station within an isolated microgrid having a wind energy conversion system as the lone and primary source. To ensure optimal performance and stability, a sophisticated smoothening band charge controller has been developed. This controller enables seamless transitions between fast and slow charging modes, effectively curbing noncritical voltage fluctuations beyond permissible thresholds. In order to demonstrate the superior efficacy of the smoothening band charge controller, a comprehensive comparative study was conducted, analyzing its performance against rapid transition controllers. The results highlight the remarkable advantages of the smoothening band approach, further solidifying its significance in future smart charging systems. To validate the proposed system, rigorous testing was carried out using the state-of-the-art OPAL-RT 4510 real-time simulator. The successful validation marks a pivotal step toward the widespread adoption of this innovative and environmentally conscious approach in the power industry.

Electric vehicle charging stations (EVCSs) are important infrastructures to support sustainable development of electric vehicles (EVs), by providing convenient, rapid charging services. Therefore, the planning of electric vehicle charging network (EVCN) has attracted wide interest from both industry and academia. In this paper, a multiobjective planning model for EVCN is developed, where a fixed number of EVCSs are planned in the traffic network (TN) to achieve two objectives, i.e., minimizing both average travel distance for charging (TDfC) of EVs and investment costs of EVCN. According to the random characteristics of EVs’ TDfC, its constraint is presented as a chance constraint in the developed EVCN planning model. The nondominated sorting genetic Algorithm II with the constraint domination principle (NSGA-II-CDP) is customized to solve the developed multiobjective EVCN planning model, by designing a special coding scheme, a crossover operator, and a mutation operator. Then, a maximum gradient principle of investment revenue is designed to select the optimal planning strategy from the Pareto-optimal solution set, when taking the investment return ratio as primary consideration. A 25-node TN is used to justify the effectiveness of the developed methodology.

When DC distribution grids with different voltage levels are connected, harmonic currents flow into the grid under light load conditions, which is a significant cause of grid instability. In this paper, we proposed a method to reduce the current ripple at light load by designing a bidirectional DC–DC converter reactor to have an inductance variable according to the load power capacity. The inductance is varied using magnetic saturation and implemented in three ways: two magnetic circuits in one magnetomotive force (MMF) circuit, a single magnetic circuit in one MMF circuit, and two magnetic components with different magnetic permeability in one MMF circuit. The feasibility is verified through simulation and experiments targeting the 750 and 380 V DC grid connection. The operating characteristics and efficiency are compared and analyzed by applying the existing and proposed variable reactor to a bidirectional DC–DC converter.

The integration of electric vehicles (EVs) as an environmentally sustainable alternative to traditional fossil fuel cars faces a range of technological obstacles, including battery technology, charging infrastructure, and standardization. Dynamic conductive road charging (DCRC) of EVs at high speed has the potential to overcome the technical limitations of existing static charging methods. An intelligent motorway system for EVs called tracked electric vehicle (TEV) was proposed to incorporate the latest technologies of dynamic road charging, autonomous driving, and smart city data into transport infrastructure. This paper presents the operation and control of an active bipolar power collection unit (PCU) for the TEV system. The PCU is seamlessly integrated within the wheel structure of an EV using the concept of a stationary-hub wheel, enabling conductive power transfer from roadside conduction rails while the vehicle is in motion. The PCU is equipped with various features designed to maintain the contact force (CF) with the conduction rails, effectively handle instances of wheel bouncing and vibrations, and ensure a consistently smooth dynamic power transfer. This paper presents the experimental validations of the active PCU controls, including the operation sequence of the PCU, CF control, and PCU interaction with wheel bouncing.

Droppers and jumpers are important components of railway overhead line electrification. Their effective maintenance is critical for the railway’s safe and reliable operation; the consequences of their failure can be disproportionally serious. This paper systematically analyses the components’ failure by applying the method of failure modes and effects analysis to the maintenance records and incident statistics of Britain’s East Coast Main Line. The analysis is presented with photographic evidence and a review of the current maintenance strategy and practice that addresses the risk of failure. These results can support improved dropper and jumper design and the development of more effective maintenance strategies to further prevent failure and operational disruption.

AbstractThis article describes the electromagnetic analysis of high efficient hybrid motor, which comprises the salient features of switched reluctance motor (SRM) and spoke‐type brushless DC motor. The main objective is to develop a motor with a high‐power density and winding faulty capability. Furthermore, this research article extends in the manner to increase the power density of the motor through the sensitivity analysis on rotor geometry by replacing the rotating part of SRM and adopting the rotor of spoke type brushless DC motor, originating the hybrid motor with the high‐power density and enhanced efficiency. To ensure the winding fault capability, a SRM‐based stator winding is adopted. Then, the modelling process for hybrid motor 48 V, 1500 RPM, 2 kW, and 12.7 Nm are detail in both analytical and finite element methods. The electromagnetic analysis is carried out to estimate the torque characteristics and flux pattern of the proposed motor. Furthermore, the proposed motor is analysed with the selection of laminating core material among M 27 24 Ga, 36F155, 46F165, 47F165, M 420 50D, and arnon 7. This infers 36F155 material assists proposed motor has high‐performance characteristics. The vibration frequencies are investigated in modal aspects to estimate the natural frequencies of vibrations. These analyses are validated among analytical and finite element results under no‐load conditions.

AbstractCurrently, there is an increased global climate change awareness, and the world is tending towards net zero emissions. The transportation sector is leading in Green House Gas emissions (GHG). Furthermore, the diminishing reserves of fossil fuels, the need for cheaper maintenance vehicles, more efficient drive trains, and better performance vehicles presents a challenge in ICE. Electric Vehicles (EVs) offer the perfect mobility solution which can replace the conventional ICE in the near future. This article comprehensively reviews the components and advances in the various technologies employed in electric vehicles to achieve efficiency in motion and optimise energy management in electric vehicles. This article gives an analysis of the current EV scenario globally. It then details the different configurations of electric vehicle architectures available. The battery is discussed, and the various electrochemical technologies are analysed. Battery Management Systems (BMS) to efficiently manage energy are discussed. The charging methods, voltage levels, and relevant standards are outlined in detail. The traction motors and power conversion technologies are reported with advancements in electric vehicle applications. Furthermore, this article gives a comprehensive overview of various emerging technologies, such as the Internet of Things (IoT), Artificial Intelligence (AI) & Machine Learning (ML), to improve EVs' performance through digitalisation. On the other hand, cybersecurity has become an ever‐challenging issue in EVs due to the increasing use of digital technologies. This article thoroughly overviews cybersecurity challenges in EV applications and explains possible proactive measures. Interoperability arising from various EV manufacturers' many different charging designs is discussed.

AbstractHybrid ships have recently garnered increasing attention as a promising solution for energy shortages and environmental pollution. However, changes in the navigation environment can greatly affect the energy efficiency of these vessels. Therefore, improving the energy efficiency of hybrid ships continues to be a key issue. Our study examined the energy efficiency of a diesel‐electric series hybrid ship operating on an inland river, and a method to optimise series hybrid ship energy efficiency was proposed. The energy consumption model, power demand model, and decision function with minimum fuel consumption as the evaluation criteria were established according to the ship's characteristics and hybrid system. By analysing the data collected from an actual ship, the operating conditions of the navigation environment were identified using the k‐means algorithm, and the total distance travelled by the ship was divided into several sub‐trajectories. Afterwards, the optimised speed of the ship and the optimised output power of each power source were determined using the grasshopper optimization algorithm. The ship's energy efficiency levels before and after using the energy efficiency enhancement method were compared and analysed, and the effects of this optimization method on the ship's energy efficiency in several typical voyages were analysed. Our findings demonstrated that this optimization method can distribute the output of the power source in a better way, thereby optimising the speed of the vessel and maintaining stable sailing. More importantly, the proposed method can reduce fuel consumption by 17.04%.

AbstractMultiple battery charging systems can be configured with various combinations of ac‐dc and dc‐dc converters. This paper reviews the reliability and economy of three representative configurations of multi‐battery charging systems. Existing PSA (part stress analysis) can analyse the failure rate considering the environmental factors for the type of parts, the number of parts, the connection state of parts and the voltage and current stress of parts. However, since it does not reflect the system's operating characteristics, the Fault‐tree analysis (FTA) method based on the fault tree is used. Still, it cannot be analysed considering the operational risk of the converter according to various load conditions. Therefore, in this study, by defining a failure according to the minimum and maximum load of the multiple battery charging systems and designing a separate fault tree, the converter operation characteristics were considered by reflecting the number of battery charges, the characteristics according to SOC (state of charge) and the redundancy effect that appears when cyclic charging is applied. Through the new enhanced FTA method, the multiple battery charging systems (Type 1) to which sequential charging is applied are quantitatively proven advantageous in terms of reliability and economy.