IET Electrical Systems in Transportation最新文献

As the most promising alternative to internal combustion engines (ICEs), electric vehicles (EVs) have an excellent development outlook. The charging route scheduling of EVs can simultaneously affect traffic congestion in the transportation network (TN) and power flow distribution in the power distribution network (PDN). The research on TN and PDN coupling networks based on the static traffic flow model is relatively mature; however, it ignores that the traffic flow will spread across periods in a short scheduling period. In this paper, a semi-dynamic traffic flow model is proposed to represent the dynamic propagation characteristics of EVs and ICEs flow. Furthermore, the cost of carbon emission and system operation are combined as the overall goal of system optimisation. Since the model has become a more complex non-linear model, this paper proposes to combine the heuristic sequential boundary tightening and binary expansion method to linearise the model. The study compared four cases and found that a 20% penetration rate of EVs can reduce carbon emissions by 4.2% while reducing the system's total cost by 10%. Moreover, the impact of network congestion on the spatiotemporal distribution of traffic flow and power flow in the coupled network is alleviated.

The deployment of DC fast charging stations (DCFCSs) in cities requires costly reinforcement of low-voltage (LV) distribution grids, due to the high power required. It results in high investments for the station operator as well as for the distribution system operator and limits the profitability of such projects. In this study, a novel concept of fast charging station which reduces the connection to the grid is presented. This station uses Vehicle-to-vehicle (V2V) power transfer from a fleet of carsharing electric vehicles to provide a high charging power while mitigating the power demand on the grid. Based on data from a carsharing operator in the city of Paris, a simulation model of a combined carsharing/V2V fast charging system is proposed, allowing to simulate carsharing trips and V2V transfers. The reduction of the grid connections required to provide fast charging is evaluated and the impact of the repeated discharges on the level of service of the carsharing system is discussed. Moreover, simulation of LV distribution grids allows to compare the grid losses of the V2V system with conventional DCFCSs.

The motive of this study is to analyse the characteristics of a novel dual-stator embedded-pole six-phase permanent magnet synchronous motor for the application of electric vehicles. A comparative analysis of two separate motor topologies, namely, dual stator embedded-pole six-phase permanent magnet synchronous motor and single stator single rotor surface-mounted permanent magnet synchronous motor, is accomplished to illustrate the performance superiority of the proposed motor. Furthermore, for optimal designing of the proposed motor, a design methodology has also been presented. For the above application, the motor should retain high torque density (HTD) and high reliability. In this regard, a novel H-Shaped flux barrier is introduced in the rotor portion, which fulfils the requirement of HTD. Moreover, the availability of two sets of the stator winding enhances the performance efficiency and ensures the proposed motor's more significant fault-tolerating ability of the motor. For performance evaluation, the Finite Element Method analysis is chosen, as it gives appropriate and precise results. From the above analysis, it is concluded that the HTD and the proposed motor's dynamic performance are better than the above-mentioned conventional motor.

Power to mass ratio is one of the key characteristics of most high-performance vehicles, a record-breaking ACCEL race aircraft is no different. Project ACCEL pushed the limits of energy management, thermal management, and mass saving, while maintaining measured safety for the pilot and crew to ultimately achieve world record-breaking flights. The numerous engineering challenges involved in designing and developing the world's fastest electric aircraft have been solved by a relatively small team in a limited timeframe. The blank sheet design of the ESS and powertrain allowed for an appropriately optimised solution, swiftly moving into physical testing allowed for rapid development of the system and opportunities to iterate. In the closing stages of the project, building, assembling, and ground testing the aircraft under one roof allowed for an effective cohesive and exciting crescendo before flight operation of the aircraft at MoD Boscombe Down.

The key to controlling harmonics in high-speed railways is to get information on its harmonic feature. In this study, a continuous 24 h harmonic observation is carried out in Ji'an West traction substation of a typical Chinese high-speed railway. In both the 24 h operating period and the two train driving processes, the features of harmonics of 27.5 kV buses are studied under multiple operating modes, which finds that the voltage and the current harmonic content mainly consist of low-order harmonics below the 11th order with high-order harmonics that ranges from 13th to 31st and 89th to 99th order. The law that the harmonic distribution changes with the load current is derived. Calculation results show a power function relationship between total harmonic distortion and bus current. In regenerative braking modes, the harmonic content is higher than traction with less high-order harmonics. Finally, the authors find an admittance matrix coupling between the 3rd to the 31st order harmonic voltage and current for simplified modelling of the harmonic transmission.

Photovoltaic-powered electric transportation systems are gaining global momentum owing to their superior enactment and zero carbon emissions. With a growing number of electric vehicles (EVs) on the road, implementation of efficient and well-organised charging stations is extremely indispensable. The authors investigate the feasibility of creating a charging station for plug-in-hybrid EVs at an educational institution, E.G.S. Pillay Engineering College, Nagapattinam, Tamil Nadu, India (10°48.2′N, 79°50.1′E). The statistics related to the solar radiations of the Nagapattinam region are employed to find out the energy availability for the EV charging station (EVCS) and the requirement for grid connection. The authors use a hybrid optimisation model for an electric renewable (HOMER) simulator to determine the optimum specification of the proposed EVCS. Also, the authors carry out a techno-economic study against the specified load requirement to evaluate the potential of the charging station. The solar irradiance data obtained from NASA ground climatology and the solar power dataset of the designated site are used to realise the precise fallouts. The optimisation results provide minimum annual system cost and reliable power to the EVs. Based on these results, an EVCS is erected in the college campus to charge plug-in hybrid electric vehicles. The established EVCS contains 3 kW EV charger operating as a microgrid and includes nine solar panels with 335 W each, 48 V, 150 Ah specification. The authors use solar photovoltaic (PV) panels using Copper Indium Selenide-Zinc sulfide (CISZS) quantum dots for maximising energy yield from the EVCS. The authors consider that eight different charging profiles for different months are employed for estimating the solar irradiance probability density in the designated site. From this study, the authors can conclude that Gaussian mixer model (G4) profile is optimum for the Nagapattinam region to install a potential and reliable EVCS.

As a power electronic converter with bidirectional energy transmission, the Dual Active Bridge (DAB) has a broad application prospect in the electrical power distribution system of hybrid-electric flight. For the DAB application in the electrical power distribution system, high efficiency and high reliability are envisaged due to the mission-critical nature of the application. A new pulse width modulation optimization control strategy is proposed, which is based on the feedback temperature fluctuations of the GaN (Gallium Nitride) power transistors, to improve the lifetime of the whole circuit. The complete topology and simulations of the DAB converter are carried out in PLECS. Detailed simulation results manifest the precise lifetime of the GaN power transistors and verify the accuracy of the new optimization control strategy. Meanwhile, Insulated Gate Bipolar Translator is set as a control group to compare the lifetime of conventional silicon-based power devices with the GaN power transistor. Hardware In Loop platform test is built to further validate the proposed method.

A novel 40-pulse autotransformer rectifier is proposed to reduce total harmonic distortion (THD) of the input current in aircraft electrical power systems. The 40-pulse rectifier (40PR) includes a passive harmonic reduction circuit (PHMC) with a low kVA rating (about 0.95% of the load power) to enhance the performance of the conventional 40PR. This PHMC is based on 2 harmonic suppression circuits and contains four tapped reactor and 4 auxiliary diodes. 50 Hz simulations of the improved 40PR indicate that THD of the input current and voltage is less than 2%, which meets the IEEE-519 standard. In addition, without using any input and output filters, input current harmonic components at 400–800 Hz are less than the requirements mentioned in the DO-160G and MIL-STD-704F standards. The suggested PHMC can easily be implemented. A prototype is developed to verify the proposed design. A good agreement can be seen in simulation and experimental results.

The precision of equivalent circuit model (ECM)-based state of charge (SoC) estimation methods is vulnerable to the variation of the battery parameters, due to several internal and external factors. In this regard, this study proposes a fuzzy logic method for the approximate estimation of the ECM parameters at different temperatures and SoC levels. The fuzzy inference system is designed to handle the non-linear deviation of the battery parameters from their reference values. On this basis, the extended Kalman filter and smooth variable structure filter are used to estimate the SoC. The two algorithms with fuzzy parameters (FP), namely FP-EKF and FP-SVSF, are tested on a 20 Ah Nickel Manganese Cobalt cell with maximum voltage of 4.2 V. The results show that the maximum root mean square error (RMSE) of the estimated SoC is kept within 1.51% with the FP-EKF and 0.68% with the FP-SVSF. Moreover, the reduction of the maximum absolute error may reach 0.34% with the FP-EKF, and 0.82% with the FP-SVSF, compared to the same algorithms without the proposed FP method. The executable codes are implemented on a low-cost controller, and the average computational time is obtained as 215 μs, which confirms the real-time practicality of the proposed method.