84 research outputs found

    Development of a 50 kW wireless power transfer system

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    A high-power modular wireless power transfer system has been developed intended for use in larger vehicles. This paper presents the design methodology and evolution of the system, including test results. The system utilises SiC switching devices and an 85 kHz operating frequency. 50 kW of wireless power transfer has been achieved over a 200 mm gap at 89% efficiency, showing good promise for the system

    A novel axial flux permanent magnet generator for wind turbines

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    This paper presents the development of a framework used to optimize and experimentally validate a novel axial flux direct-drive (DD) permanent magnet generator (PMG) for the offshore wind turbine market. This technology aims to offer significant levelized cost of energy (LCoE) reductions via capital expenditure and operating expense (CAPEX and OPEX) savings – a key objective for the offshore industry. The DD-PMG technology uses ferrite magnets to create the magnetic field, which is a significant source of cost reduction. The use of ferrite could also eliminate an industry wide reliance on Neodymium Iron Boron (NdFeB), the scarce and expensive rare-earth magnet used in existing designs. Another advantage of a ferrite-based design is that it’s less sensitive to the cooling problems that currently face existing DD-PMGs. This paper describes the development and testing of two prototype machines at nominal 2 kW and 70 kW power ratings. Moreover, the finite element analysis (FEA) and analytical steps employed to develop optimized designs together with the experimental verification are presented. The simulated and experimental results show good agreement which provides confidence in the design and modelling work completed

    Power electronics packaging for in-road wireless charging installations

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    When power electronics are deployed under the road surface as part of a wireless system it is important to know that their packaging provides adequate heat extraction as well as the required environmental protection - often conflicting requirements. Presently very little can be found in wireless charging standards and literature on the topic of thermal modelling for in-ground components. Yet, this is a topic of great practical significance especially for in-road systems. Traditional cooling methods are not readily applicable underground. This paper uses finite element thermal modelling to investigate the cooling of a representative medium-power in-road wireless system, housed in a sealed ground assembly (GA) chamber and installed to UK requirements (HAUC). The paper quantitatively compares design options and provides practical recommendations for in-road installation thermal management

    Evaluation of the operational CMEMS and coastal downstream ocean forecasting services during the storm Gloria (January 2020)

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    Storm Gloria was the 10th named storm in Europe for the 2019–2020 winter season, and it severely affected Spain and France. This powerful storm represents an excellent study case to analyze the capabilities of the different ocean model systems available in the Spanish Mediterranean coasts to simulate extreme events, as well as to assess their suitability to enhance preparedness in maritime disasters with high impacts on coastal areas. Five different operational ocean forecasting services able to predict the storm-induced ocean circulation are evaluated. Three of the systems are delivered by the Copernicus Marine Service (hereafter CMEMS): the CMEMS global scale solution (GLO-1/12°), the specific Mediterranean basin scale one (MED-1/24°), and the regional solution for the Atlantic façade (IBI-1/36°), which includes also part of the western Mediterranean. These CMEMS core products are complemented with two higher resolution models focused on more limited areas, which provide operational forecasts for coastal applications: the WMOP system developed at the Balearic Islands Coastal Observing and Forecasting System (SOCIB) with a horizontal resolution of roughly 2 km and the Puertos del Estado (PdE) SAMOA systems with a 350-m resolution that cover the coastal domains of the Spanish Port Authorities of Barcelona, Tarragona, Castellón and Almeria. Both the WMOP and SAMOA models are nested in CMEMS regional systems (MED and IBI, respectively) and constitute good examples of coastal-scale-oriented CMEMS downstream services. The skill of these five ocean models in reproducing the surface dynamics in the area during Gloria is evaluated using met-ocean in situ measurements from numerous buoys (moored in coastal and open waters) and coastal meteorological stations as a reference to track the effects of the storm in essential ocean variables such as surface current, water temperature, and salinity throughout January 2020. Furthermore, modeled surface dynamics are validated against hourly surface current fields from the two high-frequency radar systems available in the zone (the SOCIB HF-Radar system covering the eastern part of the Ibiza Channel and the PdE one at Tarragona, which covers the Ebro Delta, one of the coastal areas most impacted by Gloria). The results assess the performance of the dynamical downscaling at two different levels: first, within the own CMEMS service (with their regional products, as enhanced solutions with respect to the global one) and second in the coastal down-streaming service side (with very high-resolution models reaching coastal scales). This multi-model study case focused on Storm Gloria has allowed to identify some strengths and limitations of the systems currently in operations, and it can help outlining future model service upgrades aimed at better forecasting extreme coastal events.This study has been conducted using E.U. Copernicus Marine Service Information. Specifically, from its NRT forecast products for the global, Mediterranean basin and the IBI area. Likewise, HF radar and ocean in situ observations from the Puertos del Estado and the SOCIB observing networks and systems have been used. The authors acknowledge the MEDCLIC project (LCF/PR/PR14/11090002), funded by “La Caixa” Foundation, contributing to the development of the WMOP hydrodynamic model.Peer ReviewedPostprint (published version

    Depression at Work, Authenticity in Question: Experiencing, Concealing and Revealing

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    Australia and the UK have both introduced policies to protect employees who experience mental illness, including depression. However, a better understanding of the issues workers face (e.g. sense of moral failure) is needed for the provision of appropriate and beneficial support. We analysed 73 interviews from the UK and Australia where narratives of depression and work intersected. Participants encountered difficulties in being (and performing as if) ‘authentic’ at work, with depression contributing to confusions about the self. The diffuse post-1960s imperative to ‘be yourself’ is experienced in conflicting ways: While some participants sought support from managers and colleagues (e.g. sick leave, back to work plans), many others put on a façade in an attempt to perform the ‘well’ and ‘authentic’ employee. We outline the contradictory forces at play for participants when authenticity and visibility are expected, yet moral imperatives to be good (healthy) employees are normative

    In one’s own time: Contesting the temporality and linearity of bereavement

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    This article explores the experience and meaning of time from the perspective of caregivers who have recently been bereaved following the death of a family member. The study is situated within the broader cultural tendency to understand bereavement within the logic of stages, including the perception of bereavement as a somewhat predictable and certainly time-delimited ascent from a nadir in death to a ‘new normal’ once loss is accepted. Drawing on qualitative data from interviews with 15 bereaved family caregivers we challenge bereavement as a linear, temporally bound process, examining the multiple ways bereavement is experienced and how it variously resists ideas about the timeliness, desirability and even possibility of ‘recovery’. We posit, on the basis of these accounts, that the lived experience of bereavement offers considerable challenges to normative understandings of the social ties between the living and the dead and requires a broader reconceptualization of bereavement as an enduring affective state
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