IET Electrical Systems in Transportation最新文献

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.