Electric vehicles (EVs) appear to offer a promising solution to support sustainable transportation and the reduction of CO₂ emissions in the metropolitan areas. To satisfy the EV load demand of the new EV models with larger battery capacities, public direct-current fast-charging stations (DCFCSs) are essential to recharge EVs rapidly. A stochastic planning method of the DCFCSs is presented considering user behaviour and the probabilistic driving patterns in order to predict EVs charging demand. According to the stochastic method, a coordinated charging demand and storage charging demand are proposed with the objective of minimising peak load from EVs and charging-infrastructure costs. The proposed planning method can prevent additional grid-reinforcement costs due to EV demand during peak hours. In the coordinated charging demand, the peak load from EVs is managed by controlling the DCFCSs. Instead, in the battery energy storage (BES) charging demand, an optimal BES is proposed as an alternative solution to reduce the peak demand of EVs as well as DCFCSs operational costs. Finally, an economic analysis is carried out to evaluate the technical and economic aspects related to DCFCSs, the BES life-cycle costs as well as the financial performance of BES costs versus grid-reinforcement costs.

Plug-in electric vehicles (PEVs) are considered as innovative solutions to achieve sustainable development. The installation of PEV parking lots is the main requirement for using PEVs. Another requirement is the expansion of the distribution system to meet a portfolio of demands with different attributes including parking lots. In this study, an innovative framework for integration of parking lots in distribution system planning (DSP) problem is presented. The storage capability of gridable parking lots (GPLs) is used to postpone investments in distribution system expansion. To this end, first, a novel stochastic GPL allocation model is proposed in which GPLs can act as charging stations and storage elements. Then, an integrated model for DSP problem is presented considering different objectives of distribution system company and GPL owners. Finally, an efficient linearisation lemma is applied to solve the proposed DSP model. The numerical studies demonstrate the proficiency of the proposed DSP model.

The increasing pollution due to vehicular emissions demands a quick review of the present transportation structure. Replacing the present transportation system with an electric-based public transportation system is a possible solution. This system will use high-capacity storage devices that will be placed at the bus stops to store energy from the electric grid and then charge the buses. The implementation of such a system will require a systematic energy flow between entities such as the grid, energy storage systems, and buses. This energy flow may get interrupted due to failures between the entities and thus cause failures in the system. The objective of this work is to investigate various failures that can occur and propose strategies to minimise the impact of the failures on the operation of the system. In order to achieve this objective, a simulation model of the transportation system is developed for the analysis of different issues, which exist in the system and the fuzzy logic controller has been designed to provide solutions to these issues. The results show that with the proper working of the controller it is possible to mitigate failures that are caused due to critical energy flow disruptions.

This study presents a numerical modelling approach for the prediction of vibration and acoustic noise for a 24/16 traction switched reluctance machine (SRM). The numerical modelling includes the simulation of electromagnetic force in JMAG, the calculation of natural frequencies and the simulation of vibration and acoustic noise in ACTRAN. Considerations in the modelling of geometries, meshing and contacts of the 24/16 SRM are discussed to ensure the accuracy of the numerical simulation. Two-dimensional fast Fourier transform (FFT) is applied to the radial nodal force at the stator pole tip to analyse the dominant harmonics. FFT is also applied to the simulated surface displacement of the housing and the sound pressure at 2000 rpm to analyse their dominant frequency components. The dominant harmonics for the vibration and acoustic noise at 2000 rpm are confirmed. The numerical modelling method presented in this study can also be applied to the other SRMs and electric machines to predict the vibration behaviour and the radiated acoustic noise.

The most common system for railway high-speed lines electric supply and the somehow de-facto standard is a special AC industrial frequency system called 2 × 25 kV system. Although several studies exist showing the performance of this system in frequency and time domains, there is a lack of studies analysing how geometric parameters influence the system behaviour, mainly in terms of conductor currents. This study first introduces a simple analytic model able to explain the fundamental feats of 2 × 25 kV systems, then evaluates the effects of critical electrical and geometrical parameters on this behaviour based on mathematical relationships and numerical computations. This simple model allows understanding the main reasons why this system is able to transmit power as a 50 kV system, while trains experience just 25 kV.

This study presents a design optimisation (DO) approach for optimal component sizing of the proton exchange membrane fuel cell (PEMFC)-battery hybrid energy system (HES) and a controller design approach for DC-bus voltage regulation and load sharing control for the HES so that the proposed HES is capable of replacing the diesel locomotive WDM-3D used to haul intercity passenger trains in India. The DO approach is formulated as a multi-objective optimisation problem with objective functions of simultaneous minimisation of the total cost of HES and total fuel consumption under the operational constraints of battery state-of-charge limit and instantaneous power balance. Two energy management strategies (EMSs) are proposed for instantaneous power balance between the HES and locomotive power demand. The DO problem is solved for a chosen drive cycle using strength Pareto evolutionary algorithm-2-based particle swarm optimisation, in which an EMS is used as a subroutine. The Pareto front obtained with the multi-objective DO problem consists of a set of solutions with different sizes of PEMFC and battery. A MATLAB–Simulink model is developed with the proposed control strategy. The simulation results show that the designed controllers satisfactorily work under the dynamically varying load similar to a locomotive.

With significant interest in the use of high-temperature superconducting (HTS) components in electric aircraft, there is a need for novel modelling techniques that allow architecture-level studies of the electrical systems including HTS components. In this study, a simple electric network architecture, as proposed in the literature has been considered, which includes generators, dynamic propulsion load and cables. This electric network has been modelled considering conventional technology and using HTS cables by replacing the conventional copper cables, to evaluate the variations in the network performance. The network performance has been studied for the dynamically varying propulsion load, which is nearly equivalent to the aircraft load over the entire flight duration. Following this, electric faults have been applied at various locations, and the impact of HTS cables on the network fault levels has been evaluated. The fault current levels are compared using both conventional and HTS cables, due to the fault current limiting properties of the HTS cables, they are observed to offer lowered fault current values.

In this study, robust control methods are employed to control the permanent magnet synchronous motor. Features such as good performance despite the vehicle's load torque disturbance, measurement noise, system parameter changes and high-frequency uncertainties of structured and unstructured types make this approach more effective. The control objective is controlling and maintaining the vehicle speed and motor torque in driver's desired references. In this study, a μ controller and a reduced order μ controller are designed for the first time due to simplicity and easy implementation of the optimal controller. Simulation studies are carried out in this study to evaluate the control performance of the designed control systems. Comparison studies show that the proposed controllers have several advantages compared to the proportional–integral–derivative controller including reference speed and torque tracking, mean square error, disturbance rejection and noise attenuation.

This study presents an analysis of the harmonic content on the dc-link (battery) side in electric drives with permanent-magnet synchronous machines (PMSMs) adopting fractional-slot concentrated windings (FSCWs) which can have a significant harmonic content. An analytical expression for predicting the ripple content in the dc-link (battery) current utilising data from a two-dimensional finite element method (2D-FEM) based model is presented and found to be in good agreement with corresponding experimental results. The FEM model is also used to demonstrate that the resulting harmonic content in the phase currents when operating at speeds well above the bandwidth of a conventional proportional + integral type controller can result in a substantial increase in magnet losses. Finally, a previously reported, experimentally evaluated model of an automotive traction battery and the associated battery cable is combined with an implemented model of the FSCW-PMSM (utilising data from the 2D-FEM model), converter and control to predict the resulting harmonic content in the battery current. The presented methods can be utilised when analysing the impact of harmonics on both the ac and dc sides of an automotive electric drive system.

This study presents the quadratic boost converter (QBC) as a power electronic interface between the fuel cell (FC) stack and the DC bus of the FC vehicle (FCV). QBC provides the high voltage gain to interface the low voltage, high current and non-linear FC stack to higher voltage DC bus of the proposed architecture. The output voltage of FC is variable and is a function of cell chemistry, load variations and atmospheric conditions. Therefore, a genetic algorithm assisted fixed frequency sliding mode controller (SMC) based two-loop control strategy is proposed and developed in this study. The accuracy of the control signal generated by the SMC depends on the accuracy of reference current generation. Therefore, genetic algorithm tuned proportional–integral controller is proposed to generate the ripple-free reference current generation which follows the load-side or source-side variations. Further, a control algorithm is integrated with SMC which uses the design constants such that the chattering amplitude is suppressed and generates the control signal with fixed frequency. Consequently, the dynamic performance of the proposed controller is compared in terms of the tracking error, control effort and sliding surface error. The extensive studies are carried out under different dynamic conditions to analyse the robustness of the proposed controller for QBC-based FCV.

In this paper, a concentrated-wound exterior-rotor direct-drive electric bicycle (e-bike) mutually coupled switched reluctance motor (MCSRM) has been designed to match the performance parameters and dimensional constraints of a commercially available permanent magnet e-bike motor. Different stator and rotor pole configurations are compared for a 3-phase MCSRM. During the design process, many parameters have been evaluated and analysed. The finalised performance capabilities of all pole configurations are summarised, and the choice of pole configuration for the final design is justified. The full dynamic torque-speed performance of the finalised 15/10 MCSRM is presented, along with a detailed thermal analysis. Finally, the MCSRM performance is compared to a 12/16 non-coupled SRM and a commercially available permanent magnet motor.

This study discusses an optimised auxiliary power unit for applications in series hybrid electric vehicles (SHEVs). The auxiliary power source consists of an internal combustion engine (ICE) and a hybrid permanent magnet (HPM) generator. The ICE acts as a prime mover to the HPM generator the electrical output of which is connected to the vehicle DC-link via a passive rectifier. The vehicle primary energy is supplied by a ZEBRA battery system while the ICE/HPM generator provides a range extension. The SHEV performance is evaluated over some driving cycles using performance indicators such as driving range, fuel consumption, emissions and, battery utilisation. A dynamic model of the ICE/HPM generator system is developed and a vehicle range, with consideration of the battery dynamics, is numerically evaluated via a simulation platform. The predicted results are compared with measurements from a laboratory prototype HPM generator system, which shows a good agreement hence validating the models and simulation platform.

Urban passenger mobility challenges can be sustainably eased with electric trains. However, due to the visual impact, safety and, electrification cost concerns, some routes or section(s) of a route are not electrified. In such cases, battery powered trams present a promising alternative. Rail vehicles are heavy but, they have a low coefficient of rolling friction. Consequently, they draw high power during acceleration as compared to the power demand during cruising. Thus, a high capacity high-voltage traction battery is required to provide accelerating power. To minimise total electrified distance and traction battery size, a battery and accelerating-contact line (BACL) hybrid tram system in which a tram accelerates from a station drawing power from a short contact line and cruises with traction battery is presented. Simulated in MATLAB, the BACL hybrid tram system with 1.8 km total electrified distance has equivalent performance to the conventional battery and contact line hybrid tram system with 12.2 km total electrified distance. Compared to independently battery powered tram, battery size is reduced by 62.5%. Suggested applications for the BACL tram system are on short, fairly flat, idle lines with few stops.

In the past years, forklift manufacturers have started to hybridise their products under the worldwide interest toward electrification. This is generally made starting from existing standard products, and converting them into hybrid versions, rather than start from scratch and designing fully new vehicles. This approach involves several gaps from the inaccurate evaluation of the powertrain architecture and relative energy management strategy, up to a rough sizing of components. Therefore, this study suggests a structured methodology to follow, aimed to properly design hybrid forklift trucks. The first step is the analysis of the conventional working machine to hybridise, identifying one set of duty cycles. Then, the design of the new powertrain architecture, with a proper energy management strategy, and the definition of a numerical simulation model realised through a multiphysics object-oriented software package, to properly size the new powertrain components, and to verify energy and power flows. Finally, it is also presented a brief-cost–benefit analysis, as last verification of the proposed methodology, to verify the cost-effectiveness to bring the new products to the market. Results have shown the general feasibility of the operation since the significant reduction in fuel consumption is combined with sustainable costs of the new electrified components.