Load analysis of ground-powering systems for electric vehicles

Dynamic conductive road charging involves the transfer of power into moving Electric Vehicles (EVs) using sliding contacts. The power transfer mechanism can be either installed from the top of the car using overhead conductors, conducting rails installed along the road-side or ground-level systems embedded in the road surface. The ground-level power system is the preferred option as it minimizes aerodynamic resistance compared to the other two as well as being designed for operation with vehicles of various sizes. In addition, existing technologies used in trams can be modified to provide ground-level EV charging systems. This paper investigates a ground-level system for EVs driving at high-speed on a motorway. It is based on the Tracked Electric Vehicle (TEV) project where EVs drive autonomously in a platoon with short inter-vehicle distance to reduce the overall air drag coefficient of the platoon. The paper investigates the optimum length and distance for the ground-level system. A Simulink model is developed for platoons of 10 EVs powered from a converter. It is shown that, for a platoon of 10 EVs driving with an inter-platoon distance of 50 m, a conducting-bar section100 m in length is the most efficient in terms of load variation and voltage stability

Social exclusion of older persons: a scoping review and conceptual framework

As a concept, social exclusion has considerable potential to explain and respond to disadvantage in later life. However, in the context of ageing populations, the construct remains ambiguous. A disjointed evidence-base, spread across disparate disciplines, compounds the challenge of developing a coherent understanding of exclusion in older age. This article addresses this research deficit by presenting the findings of a two-stage scoping review encompassing seven separate reviews of the international literature pertaining to old-age social exclusion. Stage one involved a review of conceptual frameworks on old-age exclusion, identifying conceptual understandings and key domains of later-life exclusion. Stage two involved scoping reviews on each domain (six in all). Stage one identified six conceptual frameworks on old-age exclusion and six common domains across these frameworks: neighbourhood and community; services, amenities and mobility; social relations; material and financial resources; socio-cultural aspects; and civic participation. International literature concentrated on the first four domains, but indicated a general lack of research knowledge and of theoretical development. Drawing on all seven scoping reviews and a knowledge synthesis, the article presents a new definition and conceptual framework relating to old-age exclusion

Grid demand reduction for high-speed dynamic road charging by narrowing inter-vehicle distance

Dynamic road charging is a technology where electric vehicles (EVs) are continuously charged whilst driving. This technology is seen as an alternative to today’s plug-in EV charging infrastructure. The grid that feeds the dynamic road charging system must provide enough power to propel the EVs on the road. With increasing driving speed, more and more power is demanded. Highways therefore require the highest power levels from the grid. For example, charging 10 EVs driving at a speed of 125mph can result in 0.5MW grid demand. The dominant factor that determines power consumption at high speed is aerodynamic drag force. This can be minimised by using aerodynamically streamlined EVs driving in platoons. This paper investigates the impact on grid power levels by varying the inter-vehicle distance of high speed EV platooning. A Simulink model was developed, and it is shown that the grid power level can drop by 40% when 10 EVs are driving in a platoon with an inter-vehicle distance of 0.25 car lengths compared to larger inter-vehicle distance. Short inter-vehicle distance also provides power savings for the front car and, due to autonomous driving technologies, there are no safety concerns

Long-term performance of a membrane bioreactor treating table olive processing wastewater

BACKGROUND: Table olive processing wastewater (TOPW) is a seriously polluting and difficult to treat effluent, characterized by widely fluctuating pH and salinity, as well as high concentrations of organic matter and polyphenols. This systematic long-term study in a laboratory-scale pilot demonstrates that membrane bioreactor (MBR) technology is effective in substantially bio-degrading TOPW. RESULTS: After implementation of an appropriate protocol of active biomass acclimatization/proliferation, the MBR pilot was operated for 6 months with real TOPW effluent, under various operating conditions. Total organic carbon (TOC) and total polyphenol (TPh) compounds removal efficiencies were very high with mean values 91.5 and 82.8%, respectively; nutrient (N and P) removal was also satisfactory. The membrane exhibited stable performance at moderate biomass concentration, with a tendency to deteriorate at higher biomass concentration. Fouled membrane permeability could be fully restored by implementing the usual chemical cleaning protocols. CONCLUSIONS: Despite the high percentage TOC and TPh removal, the MBR effluent requires final post-treatment to remove a yellowish tint and further reduce its organic content, depending on local discharge standards. The MBR can serve as the basic treatment process in an integrated scheme for TOPW management, which needs additional R&D to further develop and optimize