Inductive power transfer (IPT) is becoming increasingly popular in stationary electric vehicle (EV) charging systems. In this paper, the influence of the different IPT coupler geometries on the performance factors such as efficiency, power density, misalignment tolerance, and stray field is studied. Four different coupler topologies, namely the circular, rectangular, double-D (DD-DD), and the double-D transmitter with double-D-quadrature receiver (DD-DDQ) are considered in this study. The electromagnetic behavior of the couplers is modeled using three-dimensional finite-element method, which is validated by experiments on a laboratory prototype. A multi-objective optimization (MOO) framework is developed to analyze the Pareto tradeoffs between conflicting performance metrics for the couplers. Optimization results depict that the circular topology performs best among the selected topologies regarding higher coupling coefficient, and efficiency for similar active mass and coupler area. Circular and rectangular couplers perform better than the polarized couplers like DD-DD and DD-DDQ regarding stray field exposure in both vertical and lateral direction of the coupler position in the EV. However, polarized couplers show more tolerance toward misalignment compared to circular and rectangular couplers. Thus, this study provides information regarding the specific strengths and weaknesses of different coupler topologies, which can be used during the initial design phase.

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Solar road technology provides an opportunity to harvest the vast, albeit dispersed, photovoltaic (PV) energy, while maximizing the land utilization. Deriving experience from the pioneering 70-m solar bike path installed in the Netherlands, this paper highlights the operational challenges and performance parameters using the first-year measured data. The theoretically predicted energy yield is compared with the measured energy yield. Based on the best performing module, the benchmark annual energy yield is set to 85&#x2013;90&#x00A0;kWh/m<formula><tex>$^2$</tex></formula> specific to the installation site. It is shown that this value can be bettered by about 1.5 times if different cell technology such as monocrystalline is used. With different installation sites around the world, thermal behavior as well as annual energy yield changes. Theoretical proof is offered that it is not unreasonable to expect an annual energy yield in the upwards of 150&#x00A0;kWh/m<formula><tex>$^2$</tex></formula> with solar road energy harvesting technology. For example, the annual yield is found to be 213&#x00A0;kWh/m<formula><tex>$^2$</tex></formula> if the same model is simulated for a solar road PV installation in India, which increased further with the use of monocrystalline to almost 300&#x00A0;kWh/m<formula><tex>$^2$</tex></formula>.

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This thesis deals with the modelling and application of magnetic fields in roads. The backbone technology being inductive power transfer (IPT) for electric vehicles. The magnetics for energy transfer in vehicles, can be adapted for heating steel fibres in roads, referred to as self-healing and modelling this is a second aspect of this thesis. The first sections of this thesis is dedicated to an overview of modelling techniques for coil design of IPT systems using both analytical and semi-analytical tools. A detailed literature review of techniques is followed by a comparison highlighting the strengths and weakness of techniques in terms of ease of use, computational efficiency, application to material interfaces etc. Analytical modelling of single and multi-coil configurations of IPT systems is carried out subsequently. The theory of partial inductance is used to model these geometries, to assess the impact of system parameters such as coupling, power transferred and magnetic efficiency with shapes of couplers and misalignment. Next, the problem of misalignment is highlighted by considering a distributed IPT system. The analytical modelling and experimental analysis of misalignment - lateral and longitudinal is performed. Edge effect is observed and experimentally validated. The second part of this thesis is dedicated to a multi-objective optimization based on the results of the developed analytical model. The goal being the development of a prototype IPT system for powering light EVs. The double rectangular (DR) coupler is chosen as the geometry for power transfer. Several geometry parameters - turns, ferrites (number, dimensions), gap between ferrites etc. are considered as design variables. Efficiency, area related power density and weight are considered as the optimization targets. Pareto fronts are developed and a particle is chosen for the development of a prototype. An experimental set-up is built consisting of a 85 kHz inverter, compensated charge-pads, rectifier and resistive load. The inverter is based on SiC MOSFETS and SiC Schottky anti-parallel diodes, the rectifier made from the same diodes. Phase shift control of the inverter legs is used to control power flow. An experimental analysis to validate the magnetic models is also developed. The third part of this thesis deals with system level economic analysis of IPT technology. A case study of bus fleet is considered and a generic methodology is developed to determine driving range as a function of mass and frontal area of the EV. The economic analysis is performed also identifying the trade-offs between road coverage of IPT, efficiency and battery size. Finally, the thesis culminates with a vision toward a future highway. Such a highway is expected to undergo a functional upgrade to handle electrification of transportation. This evolves around the integration of IPT systems, with low maintenance inductive healing asphalt roadways and renewable energy generation. The modelling challenges to such an integration is studied both using simulations and experiments. A case study for sizing renewable energy in a highway (A12) in the Netherlands using IPT is detailed.@en

Development of electric mobility and sustainable energy result in new technologies such as contactless electric vehicle charging and roadway energy harvesting methods, but also self-healing asphalt roads. By combining these technologies a new concept of Future Sustainable Roads for Electric Mobility is created and presented in the paper. This paper bridges the gap created by these unilateral technology developments using a multi-disciplinary approach including placing cautions when necessary and suggesting viable alternatives for optimal utilization of these energy transfer and conversion techniques. Through theoretical analysis, simulations, and tests on lab-scale experimental prototypes, the impact of our proposal is showcased. Thermal and loss models are developed for self-healing asphalt. Also, integration study of solar roads and contactless charging is performed. Applying the insight gained from the results, it is discussed how some challenges also pave a way towards interesting opportunities, for instance, infrastructure sharing for material use optimization and efficient mosaic integration. Finally, an economic viability case study is presented for a future Dutch highway with such newly emerging components.

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Charging infrastructure for electric vehicles (EV) will be the key factor for ensuring a smooth transition to e-mobility. This paper focuses on five technologies that will play a fundamental role in this regard: smart charging, vehicle-to-grid (V2G), charging of EVs from photovoltaic panels (PV), contactless charging and on-road charging of EVs. Smart charging of EVs is expected to enable larger penetration of EVs and renewable energy, lower the charging cost and offer better utilization of the grid infrastructure. Bidirectional EV chargers will pave the way for V2G technology where the EV can be used for energy arbitrage and demand-side management. Solar charging of EV will result in sustainable transportation and use of the EV battery as PV storage. On the other hand, stationary contactless charging and on-road inductive charging of EV will remove the necessity for any cables, eliminate range anxiety issues and pave the way for automated driving. The electromagnetic and power converter design for contactless power transfer systems for future highways is reviewed in this paper.

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Misalignment during wireless charging of EVs can lead to low efficiencies (<85%) of power transfer which can lead to thermal issues and high leakage fields. This paper explores the most optimal solution towards a misalignment tolerant system. To that end, a DD-DDQ coil system with series-series compensation combined with an impedance matching control algorithm is explored. A multi-objective optimization approach is presented to visualize the trade-off between the design aspects which result in high misalignment tolerance. Finally, the results are compared with DD-DD coil designs to quantify the advantage of the proposed system.

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This paper deals with a generic methodology to evaluate the magnetic parameters of contactless power transfer systems. Neumann's integral has been used to create a matrix method that can model the magnetics of single coils (circle, square, rectangle). The principle of superposition has been utilized to extend the theory to multi-coil geometries, such as double circular, double rectangle and double rectangle quadrature. Numerical and experimental validation has been performed to validate the analytical models developed. A rigorous application of the analysis has been carried out to study misalignment and hence the efficacy of various geometries to misalignment tolerance. The comparison of single-coil and multi-coil inductive power transfer systems (MCIPT) considering coupling variation with misalignment, power transferred and maximum efficiency is carried out.

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This paper deals with a green energy highway in the Netherlands. Here, the development of electric mobility and self-driving cars is introduced. The ideas of wireless power integration with green energy technologies - solar and wind is considered. In case of wind energy, conventional turbines and bladeless vortex are considered as options. Solaroads along the emergency lanes are also investigated. A Dutch highway A12 is considered as a case study and sizing of these energy sources for electric mobility is considered. A grid power demand profile is considered and number of EVs that can be charged hourly is calculated. A preliminary investigation of the combination of IPT and Self-Healing roads is considered in this study.@en

Inductive power transfer (IPT) systems for on-road dynamic charging of electric vehicles (EVs) must employ tracks with minimal copper and ferrite core material for improving coupling and field shaping without sacrificing on power transfer efficiency across the air gap. This paper details the multi-objective optimisation of IPT coil systems with respect to efficiency of power transfer (η), material weight or cost (w), and area-power density (α) as required in EV applications. A combination of detailed analytical calculations and experimentally verified 3D finite element models is used to analyse performance of IPT systems with polarized coupler topology [referred to as double D(DD) coils], I-shaped ferrite cores for field shaping and aluminium plates to reduce stray or leakage magnetic fields. An multi-objective pareto optimisation using Particle Swarm algorithm of a scaled 1kW prototype system with a 15 cm airgap is presented.@en

The economic viability of on-road wireless charging of electric vehicles (EVs) strongly depends on the choice of the inductive power transfer (IPT) system configuration (static or dynamic charging), charging power level and the percentage of road coverage of dynamic charging. In this paper, a case study is carried out to determine the expected investment costs involved in installing the on-road charging infrastructure for an electric bus fleet. Firstly, a generic methodology is described to determine the driving range of any EV (including electric buses) with any gross mass and frontal area. A dynamic power consumption model is developed for the EV, taking into account the rolling friction, acceleration, deceleration, aerodynamic drag, regenerative braking and Li-ion battery behavior. Based on the simulation results, the linear dependence of the battery state of charge (SoC) on the distance traveled is proven. Further, the impact of different IPT system parameters on driving range is incorporated. Economic implications of a combination of different IPT system parameters are explored for achieving the required driving range of 400 km, and the cost optimized solution is presented for the case study of an electric bus fleet. It is shown that the choice of charging power level and road coverage are interrelated in the economic context. The economic viability of reducing the capacity of the on-board battery as a trade-off between higher transport efficiency and larger on-road charging infrastructure is presented. Finally, important considerations, like the number of average running buses, scheduled stoppage time and on-board battery size, that make on-road charging an attractive option are explored. The cost break-up of various system components of the on-road charging scheme is estimated, and the final project cost and parameters are summarized. The specific cost of the wireless on-road charging system is found to be more expensive than the conventional trolley system at this point in time. With decreasing battery costs and a higher number of running buses, a more economically-viable system can be realized@en

The paper analyses the economic and environmental benefits of charging electric vehicles (EV) at workplaces in the Netherlands using photovoltaic panels (PV). A 10kW EV-PV charging system is used to charge the electric cars directly from photovoltaic panels. The cost of using a gasoline vehicle is compared with that of an electric vehicle that is charged from the grid or from solar panels. It is found that charging EV from PV results in huge savings in fuel cost, taxes and lower CO2 emissions. A comparison is made for solar panels installed on rooftops and as a solar carport and the impact of feed-in tariffs on PV generation revenues is evaluated.@en

This paper presents a comparative analysis of Multi- Coil Inductive Power Transfer (MCIPT) systems. A multi-coil magnetic system can be decomposed into a single system of coils using matrix manipulation when the system is linear. A comparitive analytical study of air-cored coils to estimate the magnetic parameters - L,M, k of several coil shapes - circular, rectangular, square, segmented circular and segmented rectangular (DD) is then carried out. A misalignment shape characteristic is obtained and comparisons brought out. Important criteria to be considered for misalignment tolerant MCIPT is also described. A boundary for performance limits of misaligned multi-coil IPT systems is presented.@en