New Zealand's (NZ) thirst for hydrocarbon-based fuels for transportation is rising exponentially, resulting in two severe consequences: first, severe emissions of greenhouse gases and a range of pollutants, and second, the dependence on foreign petroleum imports to provide those fuels. Thus there is a stimulus to develop, and to utilise, energy systems that are reliable and sustainable. The implementation of the hydrogen-based fuel cell (FC) system for electric vehicles (EVs) appears to be a promising solution because the FC is now established as a reliable, non-polluting energy source, having a high power density that competes favourably with the conventional internal combustion (IC) engine and the battery vehicle. This study provides a comprehensive review of the proton exchange membrane (PEM)-based FC, and assesses its potential in FC vehicles as an alternative to internal-combustion-based vehicles for NZ cities. The study indicates a need for FCs to penetrate the automotive market, plus key government and business strategies for the introduction of PEM EVs.

A charge equalisation controller (CEC) was developed for continuously monitoring individual battery cells and equalising the charge or voltage levels of all cells in a series pack. A charge equalisation control algorithm was developed to equalise undercharged, overcharged, and unprotected cells through the use of a bidirectional fly-back converter. The equalisation involves charging and discharging by employing constant current–constant voltage and discontinuous current mode proportional–integral (PI) control techniques. Particle swarm optimisation is applied to optimising the PI controller parameters that generate the regulated pulse width modulation switching signal for the converter. A CEC model was applied to 90 lithium-ion battery cells (nominally 15.5 Ah and 3.7 V each) connected in series. The results showed that the developed CEC model performed well at equalising both undercharged and overcharged cells with ∼92% efficiency and equalised every cell within the safe operation range of 3.73–3.87 V. The developed system realises excellent equalisation speed, a simple design and efficiency with low power loss. Thus, the CEC model has great potential for implementation in real-world electric vehicle energy storage systems.

Realisation of electrically boosted turbochargers requires electric motors capable of operating at very high speeds. These motors often use a permanent magnet rotor with the magnets retained within an interference fit external sleeve. Whilst it is possible to model such systems numerically, these models are an inefficient tool for design optimisation. Current analytical models of rotors typically consider the stresses induced by the shrink fit of the sleeve separately from the stresses generated by centripetal forces due to rotation. However, such an approach ignores the frictional interaction between the components in the axial direction. This paper presents an analytical model that simultaneously accounts for interaction between the magnet and outer sleeve in both the radial and axial directions at designed interference and with the assembly subjected to centripetal and thermal loads. Numerical models presented show that with only moderate coefficients of friction and rotor lengths; axial load transfer between magnet and sleeve takes place over a short distance at the ends of the assembly. This paper then demonstrates how the analytical model aids definition of a feasible set of rotor designs and selection of an optimum design.

There is a growing interest worldwide in reducing pollution and CO₂ emissions from transportation field. Indeed, in recent years bus manufacturers have developed hybrid and electric versions of their products. In this regard, this study shows through a structured methodology how to model and design powertrains for pure electric and series-hybrid buses. First step is aimed to define a simulation model of the existing bus, experimentally validated, and then modelling and design of pure electric and hybrid powertrains. After analysing main drawbacks of pure electric vehicles fed by large and heavy batteries, and hybrid vehicles fed by diesel fuel, alternative solutions have been considered. In particular, different fuels, i.e. compressed natural or liquefied natural gas, have been analysed for the hybrid version, while a pure electric vehicle equipped with a reduced storage system able to be quickly recharged at bus stops has been introduced. In all the considered cases, particular attention has concerned the sizing of the electrochemical storage.

An automated people mover (APM) is a system used in urban/suburban areas to transport passengers point to point with a high frequency and a reliable service. Although conventional wheel-on-rail/route systems are commonly used in APMs, the application of the magnetic levitation (MAGLEV) technology in this field sounds promising. Since this technology replaces the wheels by electromagnetic systems, there is no contact between the levitating vehicle and the guideway. This implies zero wear, reduced maintenance and virtually no noise and vibrations. Efficiency, lightweight and cheapness represent expected additional benefits. The aim of thisstudy is to show, through a theoretical analysis based on a real APM and on a simulated automated MAGLEV people mover (AMPM), how the low-speed MAGLEV applications can compete with conventional wheel/rail technology. The levitation and guiding forces in a permanent magnets-based AMPM have been obtained by using an FEM code. Then, a simulation tool, based on Modelica language, has been developed to perform a comparison between a conventional APM and an AMPM, in terms of power and energy requirements engaged in urban routes. Finally, a brief preliminary estimation of costs for the major AMPM subsystems has been presented.

dc/dc Power converters are increasingly used in vehicular power systems with their control systems re-designed to overcome the challenges associated with the wide voltage and load variations and the non-linear behaviour of constant power loads (CPLs). Within this context, this study investigates the implementation of a non-linear time-delay control (TDC) system in dc/dc power converters. This non-linear controller compares the system response with the response of a reference model, and then generates a control signal which forces the system to follow the reference model. The TDC system is designed to tightly regulate the output voltage of a conventional dc/dc boost converter under input voltage and load variations. Furthermore, the stability of the TD controller following to the CPL variations is studied. To verify the effectiveness of TD controller, its performance is compared with an integral-double-lead controller using MATLAB software.

Vehicle-to-grid systems facilitate efficient and reliable integration of electric vehicle (EV) into the smart grid. This integration helps provide various services such as peak load levelling, frequency regulation (FR) and other ancillary services that provide notable benefits to utilities. In addition to the benefits to the utilities, EV owners may also benefit from providing these ancillary services to the grid. In this study, a comprehensive assessment of the economic benefits of using EVs to support FR service to the power grid is developed. The limitations for providing such services to the grid are evaluated. The number of the charge and discharge cycles of the EV battery is estimated based on a realistic semi-logarithmic model. Finally, the estimates are used to calculate the battery degradation cost for providing FR and estimate the safe amount of power that EVs can supply with adequate consideration for daily driving requirements.

Supercapacitor is being widely used in electric transportation applications, particularly in electric vehicles (EVs). In the EV, the supercapacitor mainly serves as energy storage system for accelerating the vehicle and/or capturing the braking energy due to its prominent features such as high power density and long life cycle. However, during the vehicle braking and/or accelerating, deep and fast supercapacitor charging-discharging cycles increase the electric and thermal stresses on the supercapacitor bank. Under such circumstances, condition monitoring of the supercapacitor bank is essential in EVs for safe operation of the storage system. In this paper, an effective method for condition monitoring and fault diagnosis of the supercapacitor banks is proposed. First, it is shown that the equivalent series resistance (ESR) and double-layer capacitance (CDL) can be used as the key signatures for indicating the state-of-health. Subsequently, the recursive extended least-square algorithm (RELS) is used for online estimation of the ESR and capacitance of the supercapacitor bank. Based on a residual signal which is defined as the difference between the voltages of the supercapacitor bank and RELS algorithm, the abnormal conditions of the supercapacitor bank are distinguished. Experimental results are presented to confirm the feasibility and precision of the proposed method.

Recently, there has been a growing interest in reducing the number or replacing the hydraulic/pneumatic actuators utilised on aircraft with electric actuators coupled to mechanical gears, which would improve the reliability and performance. This is involved in the concept of more electric aircraft. The electrification of actuators would affect the primary and secondary flight controls, as well as the movement of flight surfaces, retraction of the landing gear, and steering of the nose landing gear, which is also considered in this study. This study considers the design of a multiphase permanent-magnet (PM) motor to be utilised for the electric steering of a commercial aircraft nose landing gear. This multiphase motor would make it possible to achieve a highly reliable actuator and, coupled with a harmonic drive, avoid the use of a multi-motor configuration. Moreover, a multiphase motor would increase the power density and efficiency of the actuator, through improving the torque ripple. The performance variation due to temperature swings is considered, and a design procedure for the PM motor is described using the worse operation case for the electric actuator. The adequate performance of the designed motor and actuator is demonstrated by means of a finite element analysis.