Electrified Road Research Articles

2D Multilayer solution for an electrified road with a built-in charging box

Charging electric vehicles inductively as they are being driven on the road is a conceivable option through a prefabricated charging box placed underneath the top asphalt layer of existing flexible pavements. Such a box inclusion however generates a material discontinuity in the pavement layer and points of singularities, inducing failure in the materials involved under heavy moving loads. To design such an electrified road, the specific model proposed here yields parametric calculations of multilayered structures embedded in a crack. By separating the problem into multiple zones across different material layers in a cross-sectional geometry, the multilayered solution presented provides all the mechanical fields and interface stresses between layers. On an electrified road case study from the literature, a vertical crack between box and material layer extends applicability of this mechanical solution to predicting failures like layer debonding. An alternative top pavement layer material is suggested for future developments.

Life cycle sustainability assessment of electrified road systems

The widespread use of Electric Vehicles (EVs) has been one of the main directions for pursuing a sustainable future of road transport in which the deployment of the associated charging infrastructures, static or dynamic, has been included as one of the main cornerstones for its success. Different electrified road (eRoad) systems which allow for dynamic charging of EVs by transferring electrical power from the road to the vehicle in-motion, either in a conductive or contactless way, are under active investigation. One of the important tasks in feasibility analysis of such infrastructure is to quantitatively assess its environmental performance and, thus, the consequential influences to the sustainability of road electrification as a whole. Having this concern in mind, in this study, a systematic LCA study is carried out in which the environmental impacts from the different life cycle stages have been calculated and compared among several promising eRoad systems. In a next step, suitable strategies can be accordingly made to minimise these impacts in a most effective way; and more importantly, the LCA results of this study can serve as one of the important bases for conducting a more comprehensive and objective evaluation of the potential environmental benefits EVs could bring.

Life cycle assessment of permanent magnet electric traction motors

Ongoing development of electrified road vehicles entails a risk of conflict between resource issues and the reduction of greenhouse gas emissions. In this study, the environmental impact of the core design and magnet material for three electric vehicle traction motors was explored with life cycle assessment (LCA): two permanent magnet synchronous machines with neodymium-dysprosium-iron-boron or samarium-cobalt magnets, and a permanent magnet-assisted synchronous reluctance machine (PM-assisted SynRM) with strontium-ferrite magnets. These combinations of motor types and magnets, although highly relevant for vehicles, are new subjects for LCA. The study included substantial data compilation, machine design and drive-cycle calculations. All motors handle equal take-off, top speed, and driving conditions. The production (except of magnets) and use phases are modeled for two countries – Sweden and the USA – to exemplify the effects of different electricity supply. Impacts on climate change and human toxicity were found to be most important. Complete manufacturing range within 1.7–2.0 g CO2-eq./km for all options. The PM-assisted SynRM has the highest efficiency and lowest emissions of CO2. Copper production is significant for toxicity impacts and effects on human health, with problematic emissions from mining. Resource depletion results are divergent depending on evaluation method, but a sensitivity analysis proved other results to be robust. Key motor design targets are identified: high energy efficiency, slender housings, compact end-windings, segmented laminates to reduce production scrap, and easy disassembly.

Impacts of electric vehicles on the electricity generation portfolio – A Scandinavian-German case study

This study investigates how electrification of the Scandinavian and German road transportation sectors under a stringent CO2 cap will influence investments in new electricity generation capacity up to Year 2050 and the dispatch of the electricity generation portfolio in Year 2030. We apply a cost-minimisation investment model and an electricity dispatch model of the Scandinavian and German electricity systems, assuming both optimised charging and a vehicle-to-grid (V2G) charging strategy for passenger electric vehicles (EVs). Different EV battery sizes and EV deployment levels are investigated in 11 different scenarios, whereby two of the scenarios include also electric trucks and buses using electric road systems (ERS). The results of the modelling show that with a cap on CO2 emissions, the additional electricity demand from an electrified road transport sector is met mainly by increases in the outputs from wind power and thermal power plants, in the form of coal in combination with carbon capture and storage. In Year 2030, wind power generation in Scandinavia and Germany increases by 7–30% depending on the EV scenario, as compared to a scenario without EVs, which corresponds to a few more percentage points than the increased demand from EVs in absolute terms. Furthermore, a V2G charging strategy for passenger EVs smoothens the net load curve and almost completely reduces the need for peak power capacity in the Scandinavian-German electricity system. The value of investing in solar power is also reduced in all the EV scenarios by 22–42%, as compared to a scenario without EVs. This is due to the fact that in Northern Europe solar power competes with EVs for peak power supply. ERS for mainly trucks and buses will increase the current load profile by up to 18 GW in the Scandinavian-German electricity system.

Dynamic charging infrastructure deployment for plug-in hybrid electric trucks

Inspired by the rapid development of charging-while-driving (CWD) technology, plans are ongoing in government agencies worldwide for the development of electrified road freight transportation systems through the deployment of dynamic charging lanes. This en route method for the charging of plug-in hybrid electric trucks is expected to supplement the more conventional charging technique, thus enabling significant reduction in fossil fuel consumption and pollutant emission from road freight transportation. In this study, we investigated the optimal deployment of dynamic charging lanes for plug-in hybrid electric trucks. First, we developed a multi-class multi-criteria user equilibrium model of the route choice behaviors of truck and passenger car drivers and the resultant equilibrium flow distributions. Considering that the developed user equilibrium model may have non-unique flow distributions, a robust deployment of dynamic charging lanes that optimizes the system performance under the worst-case flow distributions was targeted. The problem was formulated as a generalized semi-infinite min-max program, and a heuristic algorithm for solving it was proposed. This paper includes numerical examples that were used to demonstrate the application of the developed models and solution algorithms.

Dynamic application of the Inductive Power Transfer (IPT) systems in an electrified road: Dielectric power loss due to pavement materials

Inductive Power Transfer (IPT) technology is seen as a promising solution to be applied in an electrified road (eRoad) to charge Electric Vehicles (EVs) dynamically, i.e. while they are in motion. Focus in this study was placed on the dielectric loss effect of pavement surfacing materials on the inductive power transfer efficiency, induced after the integration of the technology into the physical road structure. A combined experimental and model prediction analysis was carried out to calculate this dielectric loss magnitude, based on which some preliminary conclusions as well as a prioritization of future focus needs were summarized in detail.

Towards an understanding of the structural performance of future electrified roads: a finite element simulation study

ABSTRACTNowadays, many novel technologies are under investigations for making our road infrastructure function beyond providing mobility and embrace other features that can promote the sustainability development of road transport sector. These new roads are often referred to as multifunctional or ‘smart’ roads. Focus in this paper is given to the structural aspects of a particular smart road solution called electrified road or ‘eRoad’, which is based on enabling the inductive power transfer technology to charge electric vehicles dynamically. Specifically, a new mechanistic-based methodology is firstly presented, using a finite element simulation and an advanced constitutive model for the asphalt concrete materials. Based on this, the mechanical responses of a potential eRoad structure under typical traffic loading conditions are predicted and analysed thoroughly. The main contributions of this paper include thus: (1) introducing a new methodology for analysing a pavement structure purely based on mechanistic principles; (2) utilising this methodology for the investigation of a future multifunctional road pavement structure, such as an eRoad; and (3) providing some practical guidance for an eRoad pavement design and the implementation into practice.

Charging strategies – implications on the interaction between an electrified road infrastructure and the stationary electricity system

This study uses a vehicle model together with detailed traffic data of the European route 39 in western Norway to estimate how the electricity demand for an electric road system varies with time and location. The aim is to better understand the impact of an electric road system on the stationary electricity system. The results show that the electricity demand for an E39 electric road system is comparable to a larger industry, potentially increasing the peak power demand in the regional electricity system with only a few percent. Yet, if all main Norwegian roads are electrified, or if vehicles can also charge their batteries while driving, there will be a significant (>10%) addition of electricity demand to the current load.

An improved high-performance lithium–air battery

Although dominating the consumer electronics markets as the power source of choice for popular portable devices, the common lithium battery is not yet suited for use in sustainable electrified road transport. The development of advanced, higher-energy lithium batteries is essential in the rapid establishment of the electric car market. Owing to its exceptionally high energy potentiality, the lithium-air battery is a very appealing candidate for fulfilling this role. However, the performance of such batteries has been limited to only a few charge-discharge cycles with low rate capability. Here, by choosing a suitable stable electrolyte and appropriate cell design, we demonstrate a lithium-air battery capable of operating over many cycles with capacity and rate values as high as 5,000 mAh g(carbon)(-1) and 3 A g(carbon)(-1), respectively. For this battery we estimate an energy density value that is much higher than those offered by the currently available lithium-ion battery technology.

The Impact of Transport Electrification on Electrical Networks

In order to satisfy the growing expectation for energy-efficient ecofriendly transportation, a number of vehicle concepts have emerged, including the hybrid electric vehicle (HEV) and battery electric vehicle. Vehicle dynamics necessitate careful sizing of onboard energy storage systems. As the penetration of electric vehicles, in both the public and private sector increases, the requirement to facilitate and utilize them becomes paramount. A particular class of vehicle, the plug-in HEV also poses a greater challenge to existing terrestrial-based electrical supply systems. This paper establishes a series of well-defined electric vehicle loads that are subsequently used to analyze their electrical energy usage and storage in the context of more electrified road transportation. These requirements are then applied to a European Union residential load profile to evaluate the impact of increasing electrification of private road vehicles on local loads and the potential for vehicle and residential load integration in the U.K.