IET Electrical Systems in Transportation最新文献

Currently, 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.

Multiple 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.

Hybrid 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%.

Low-frequency oscillation, harmonic oscillation and harmonic instability issues in railway vehicle-grid systems pose challenges to the system stability and safe operation. Previous studies constructed the linear time-invariant impedance model of vehicle-grid system, which ignored the internal frequency coupling and loss of model accuracy. To fill this gap, the impedance modelling method based on the harmonic linearisation method of the vehicle-grid system is proposed. The derived model provides a clear physical insight into the harmonic coupling relations between ac and dc variables and improves the model accuracy. Then, a systematic analysis of harmonic stability in the railway vehicle-grid system is analysed based on the proposed model. The electrical and control parameters on system stability at the frequencies above and below the fundamental frequency are summarised. The mechanisms of these oscillation issues in railway vehicle-grid systems are then discussed. Finally, the model accuracy and stability analysis results are verified by the frequency scan method and hardware-in-the-loop results.

The reliable performance of the shipboard power system (SPS) is essential for the safe and efficient operation of marine vessels. SPSs are subject to various types of electrical faults that can cause equipment failure, system downtime, and even catastrophic events. One effective way to provide redundancy and fault tolerance in the event of a fault or failure is through the use of zonal configuration. However, the protection of such systems is a challenging task due to their complex topology and the potential for multiple sources of fault. Therefore, it is imperative to protect the SPS with zonal configuration from various types of fault to ensure its continuous operation. This article presents a comprehensive coordinated protection strategy for a hybrid AC/DC SPS with the zonal configuration by using the available protective equipment. The proposed strategy consists of fault current limiting, grounding, fault detection, and faulty section isolation, and provides both primary and backup protections for all SPS equipment, including generator, busbar, line, input and output feeders, loads, propulsion motors, and DC system. Also, it does not require a comprehensive communication infrastructure and training dataset. The selective and reliable performance of the proposed protection strategy is verified through several case studies under various fault scenarios in the ETAP environment. The article provides valuable insights into the selection and implementation of appropriate protection measures for the SPS with ring configuration which are useful for the designers, operators, and maintenance personnel, improving the reliability and safety of these critical and autonomous systems.

This paper presents the current scenario related to the application of power electronics converters in aviation industries, major challenges and their reliability aspects. Recent developments in power electronics have given a major breakthrough in the aviation industry. These developments are not only limited to the more electric aircraft (MEA) but also in the field of electric propulsion, popularised as electric propulsion aircraft (EPA). The aircraft requires a well-established protection scheme of these converter topologies. The overall reliability of aircraft solely depends on its protection and fast mitigation of any fault if occurs in the cruise time. This paper aims to provide a comprehensive analysis of power converters applications in MEA and EPA. Further, a review of various topologies of Power Converters and their reliability assessment is also described in detail. The physics of Failure of switches, their lifetime estimation and thermal cycling have also been discussed. Finally, the reliability assessment of different topologies and their comparison has been discussed for overall performance enhancement of the MEA and EPA.

Hybrid energy storage systems (HESSs) have gradually been viewed as essential energy/power buffers to balance the generation and load sides of fully electrified ships. To resolve the balance issue of HESS under multiple power resources, that is, shipboard diesel generators and fuel cells (FCs), this study proposes a robust sizing method implemented with a power allocation strategy. The proposed method is hierarchically formulated as two sequential sub-problems: (1) a robust programming to determine the power/energy capacities of HESS under the maximal power demand scenario and (2) a control framework to fulfil the power allocation under multiple power resources. A ship case with one diesel engine and one FC is studied to show the validity of the proposed method. The simulation results show that the integration of HESS facilitates the power supply of critical propulsion loads. Compared with no HESS, HESS integration can reduce the deviation of direct current bus voltage sag by 56% and reduce the power fluctuations of the main engine and FC by 7.3% and 55.9%, respectively.

The More-Electric Engine (MEE), with its electrified engine auxiliary systems and increased multi-shaft power offtake, is likely to become an increasingly central aspect of future More-Electric Aircraft. Consequently, lightweight but resilient electrical power architectures are needed for these future MEE applications. However, whilst a range of MEE architectures exist in the research literature, no effective baseline architecture or standardised feature identification has been proposed to specifically address their unique design requirements. Accordingly, any underpinning technology-focused research for critical MEE subsystems may ultimately have a reduced effectiveness without this credible baseline. Based on comprehensive design analyses, preliminary design requirements and anticipated operational modes, this article proposes key design rules for the formation of the first generic baseline MEE electrical power system architecture concept. Guidance is provided on features such as the number of power generation systems, the number and topologies of distribution channels, type of power conversion, essential load redundancy, and the location of emergency power supply. This article also provides full transparency of the design process so that key decision points can be revisited to capture application-specific requirements and updates to certification requirements.

Due to the interaction of electric multiple units (EMUs), and the electric traction networks, low frequency oscillations (LFOs) appear leading to traction blockade and overall stability related issues. For suppressing LFOs, coronavirus herd immunity optimiser (CHIO), a recently developed meta-heuristic, has been applied for tuning controller parameters. Controller parameters are tuned to minimise the integral time absolute error (ITAE) that regulates DC-link capacitor voltage. Results obtained using CHIO are compared with those found using other well-established algorithms like symbiotic organisms search (SOS) and particle swarm optimisation (PSO). The supremacy of CHIO over other mentioned algorithms for mitigating LFOs was demonstrated for a diverse range of operating conditions. Results demonstrates that overshoot for the proposed algorithm-based traction unit is 1.0061% whereas those for SOS and PSO based algorithm are obtained as 6.4542 % and 20.6166%, respectively which are quite high. CHIO is more stable than SOS and PSO and requires settling time of 0.1934 s only to reach steady-state condition, which is 50.21% faster than SOS and 65.03% faster than PSO. Also, the total harmonic distortion (THD) for line currents of the secondary side of traction transformer (TT) are obtained as 0.88%, 2.17%, and 12.48% for CHIO, SOS, and PSO, respectively.

In this article, three dual-stator axial field flux-switching permanent magnet (DS-AFFSPM) topologies are selected, designed, and analysed in order to determine the most effective structure electric vehicle (EV) application based on torque density, power density, and efficiency. Accordingly, the introduced topologies are thoroughly compared in the same condition. The results show that, the high-power density, high-torque density, and high-efficiency, of the internal single-teeth rotor DS-AFFSPM topology is a suitable candidate for EV application because it has the lowest torque ripple.