1,174 research outputs found
Wind Energy and Atmospheric Physics Department annual progress report 1999
The report describes the work of the Wind Energy and Atmospheric Physics Department at Risø National Laboratory in 1999. The research of the department aims to develop new opportunities in the exploitation of wind energy and to map and alleviateatmospheric aspects of environmental problems. The expertise of the department is utilised in commercial activities such as wind turbine testing and certification, training programmes, courses and consultancy services to industry, authorities and Danishand international organisations on wind energy and atmospheric environmental impact. A sum-mary of the department's activities in 1999 is presented, including lists of publications, lectures, committees and staff members
Advance control strategies for Maglev suspension systems
The Birmingham Maglev developed over fifteen years ago has successfully demonstrated
the inherent advantages of low speed maglev over comparable wheeled systems. It
remains the only commercially operational Maglev in the world today. To develop the
next generation of Maglev vehicles which will overcome some of the limitations of the
Birmingham system, such as chassis length and cost, the following issues are addressed
in this thesis.
1) The possibility of interaction between the chassis resonant frequencies and the
suspension control system causing poor ride quality and at worst instability, are
formally analysed. In the Birmingham vehicle a stiff chassis (fundamental bending
mode 40Hz) is used avoiding significant interaction with the suspension controller.
Using advanced control strategies the low frequency chassis resonances can be
controlled allowing a vehicle structure to be used with a fundamental bending
mode of about 12Hz.
2) A modem control strategy is developed which delivers an improved ride quality
compared with the present classical control system despite having to operate with
a 'soft' chassis. Kalman filters are digitally implemented and conclusions drawn
about their performance. The classical control strategy is also successfully
demonstrated on a 3 m long 'flexible beam' rig.
3) An associated Maglev suspension problem for the response to ramp inputs such
as the transition onto gradients which causes either a large steady state tracking
error or a worsening ride quality is addressed by modern control theory using
integral feedback techniques and classical theory using third order filters. These
controllers are globally optimised by a multi-objective parameter optimisation
system which formally considers the conflicts inherent in a suspension system
between response to stochastic inputs and deterministic inputs
A micro to macro investigation on Electric Vehicle Policy in the UK: Work Package 3 Activity 6 report.
Written by E-Mobility NSR partners Richard Kotter (Northumbria University) and Dr Stephen Shaw (London Metropolitan University, Cities Institute), the report considers how the step change to mainstream market acceptance of Electric Vehicles (EVs) is being supported by macro-level policy to secure economic as well as environmental benefits.
Particular reference is made to the UK, where interventions include grants to purchase new plug-in cars and vans, tax exemptions, and match-funding from the government for 'Plugged-In Places': pilot schemes designed to stimulate innovation and development of EV infrastructure at the meso-level of areas within the country.
There are also examples of local authorities outside the Plugged-In Places areas that have found other thematic and enabling ways to invest into E-mobility. This is supplemented by private sector commercial investment additional to and outside of the eight Plugged-In Places areas in the UK. It considers how the vision for each area is, in turn, being scaled down to the micro-level of streets and parking spaces. It also reports on the latest government policy to spread EV charging infrastructure around the country.
The report concludes that Local Authorities will play a leading role in developing a charging network that is comprehensive, inter-operable and easy to use. Working in collaboration with other key stakeholders, they must be equipped for two critical challenges:
- Scaling up to the 'bigger picture': to raise the confidence of EV users who wish to make longer trips (including low carbon journeys where EVs are part of the modes of transport), including transnational journeys through international transport hubs to/from other NSR countries via ferry ports, airports and the Channel Tunnel
- Scaling down to 'street level': to ensure that EV users, especially those who are less familiar with the locality, have the confidence to find publicly-accessible points, plug-in, and leave their vehicles charging 'Methodologies for Mutual Learning: a Digital Map Interface for Effective EV Infrastructure' - a supplementary paper to the main report - outlines methodologies to help stakeholders address these challenges and exchange good practice
Stone Conservation: An Overview of Current Research
Offers a subjective analysis of what is being done right, what areas of research should be continued, and what new directions should be addressed to increase the effectiveness of stone conservation
Improving the performance of railway track-switching through the introduction of fault tolerance
In the future, the performance of the railway system must be improved to accommodate increasing passenger volumes and service quality demands. Track switches are a vital part of the rail infrastructure, enabling traffic to take different routes. All modern switch designs have evolved from a design first patented in 1832. However, switches present single points of failure, require frequent and costly maintenance interventions, and restrict network capacity. Fault tolerance is the practice of preventing subsystem faults propagating to whole-system failures. Existing switches are not considered fault tolerant. This thesis describes the development and potential performance of fault-tolerant railway track switching solutions. The work first presents a requirements definition and evaluation framework which can be used to select candidate designs from a range of novel switching solutions. A candidate design with the potential to exceed the performance of existing designs is selected. This design is then modelled to ascertain its practical feasibility alongside potential reliability, availability, maintainability and capacity performance. The design and construction of a laboratory scale demonstrator of the design is described. The modelling results show that the performance of the fault tolerant design may exceed that of traditional switches. Reliability and availability performance increases significantly, whilst capacity gains are present but more marginal without the associated relaxation of rules regarding junction control. However, the work also identifies significant areas of future work before such an approach could be adopted in practice
- …