Sub-agent elements for control methods in multi-agent energy management system

Increased penetration of generation and decentralised control are considered to be feasible and effective solution for reducing cost and emissions and hence efficiency associated with power generation and distribution. Distributed generation in combination with the multi-agent technology are perfect candidates for this solution. Pro-active and autonomous nature of multi-agent systems can provide an effective platform for decentralised control whilst improving reliability and flexibility of the grid

European perspectives on a new fiscal framework for transport

This chapter presents an overview of changes in transport taxation in European countries to promote more sustainable transport. A number of changes in the framework of car taxation have resulted in some useful environmental gains. However, these changes are limited because the transport tax system has been designed to produce a substantial income from internal-combustion-engine vehicles in an easily administered form. A major restructuring of transport taxation is required to fully address a different goal – that of stimulating improvements to environmental performance. A generalised road user charging-based system could be the way forward. Such a system is now seen by several European countries and some USA states as the transport taxation regime for the 21st century. Tax regime change is emerging onto the transport policy agenda as a vital long-term strategy. Largely by default, transport policy-makers are coming to realise that road taxation regime change is inevitable if traffic and congestion management is to be a reality. The way we taxed vehicles and fuel in the 20th century is simply not appropriate for the transport challenges we face today

Site Structure And Organization In Central Alaska: Archaeological Investigations At Gerstle River

Thesis (Ph.D.) University of Alaska Fairbanks, 2005This dissertation presents a multi-dimensional analysis of site structure and organization at a multi-component deeply buried stratified site in the Tanana Basin in Interior Alaska, Gerstle River. The primary objective of this research is to investigate patterning among the lithics, fauna, features, stratigraphy, and radiometric dating, within and among components and intra-component hierarchical spatial aggregates. These analyses are situated within and are explored in terms of technological and spatial organization. Given the longevity of microblade technology (12000 BP to ~1000 BP) and its presence in very different climatic and biotic regimes, understanding how microblades were used within a technological system and possible variations in microblade use could be useful in understanding technological change during the Pleistocene-Holocene transition and later Holocene times. This research analyzes microblades and other lithic classes at a number of levels (e.g., attribute, artifact, raw material, modification type, cluster, area, component, and site). Results show a number of organizational properties used by Early Holocene populations at Gerstle River, providing a dataset useful for testing future models derived from experimental, ethnoarchaeological, and other middle range approaches. Patterns of technology and technological organization are more highly resolved when incorporating spatial analyses. Microblade technology is shown to be structurally complex, used for a variety of purposes and reflecting different stages of production and different modes of use and disposal, including microblade production, replacement, and discard. Inferences about faunal procurement, subsistence, transport decisions, settlement patterns, and economy are made through a multidimensional faunal analysis. Non-human factors were not major agents in the formation of the assemblages. A spatial model of faunal processing indicates how space was used in processing multiple individuals of wapiti and bison. Contextual data from lithic technology, faunal remains, features, radiocarbon dating, and spatial relationships are used to model several dimensions of organization present at Gerstle River, including site activities, technological organization, disposal modes, organization of space, redundancy, storage, seasonality, location, group size and economic structure, economy, and settlement system

Taxation Futures for Sustainable Mobility: final report to the ESRC

The existing transport tax and charging regime has stimulated limited behavioural change and has been politically problematic (as demonstrated by the September 2000 fuel duty protests). This project synthesised a range of research that has explored ways in which road user charging could replace the present regime based on taxing fuels and car ownership. In 2002, when this project was proposed, this was a fringe transport policy issue. Throughout 2003 the subject achieved a sudden prominence, with a government working party being established to explore the possibility of long-term area-wide road user charging. A tax regime change towards a car road user charge for cars has occurred, or is being considered, in societies as contrasting as Oregon State in the USA, the Netherlands, Switzerland and the UK, reflecting a range of policy considerations. For the UK, these include: the ongoing failure of transport policy measures to achieve adequate cuts in congestion and emissions; the success of the London Congestion Charge; the rise in the cost of transport policy interventions; the reduction in Treasury income of eco-reforms to the current tax regime; and the difficulties of, and equity issues relating to, taxing fuel in a future multi-fuel transport sector. The project developed tax change scenarios in conjunction with the project's user group (including policymakers, NGOs and researchers). Five scenarios were modelled using an adaptation of the Dutch Mobility Explorer program. An 'opt-in' transitional policy mechanism involved replacing VED with a small flat-rate kilometre charge for cars of 0.77 p/km. The model suggested it would have little policy impact, but could be used to familiarise car drivers with the concept of a distance charge. A fiscally neutral scenario involved the replacement of VED and Fuel Duty with a banded kilometre charge for cars of between 2.3 and 8.5 p/km (varied by the environmental performance of the vehicle type). This induced little behaviour change, reducing car driver mobility by only 4%. A further scenario, restored the tax revenues lost from post-2000 tax changes, generating an additional £3 billion or £6b per annum. These reduced car driver mobility by 9% - 14%, and total CO2 emissions were predicted to drop by 6% - 9% by 2015, compared to the base scenario. The type of change involved in the revenue-raising scenarios is significant. There would be only a small increase in the use of public transport, with the predominant response being the better utilisation of cars with higher occupancy and more linking of trips to cut distances driven. The project results suggest that road user charging may deliver more revenue stability than fuel taxation. However, clarity is needed over the policy goals – congestion reduction, emission reduction, revenue stability – for a national road user charge, because the goals are not necessarily complementary. It should also be emphasised that a change of tax regime would not remove the need the hard political decisions in this area

Embodied carbon dioxide of network assets in a decarbonised electricity grid

Calculating carbon dioxide ( {CO} 2 ) emissions associated with electricity is a key component in the field of Life Cycle Assessment (LCA), but is often cited as challenging due to the complex nature of electricity systems despite its importance to the outcome. While calculating the operational {CO} 2 emissions associated with electricity generation is an active research field, the embodied {CO} 2 emissions, typically referred to as embodied carbon, of network assets has far less representation in the literature. This paper focuses on the {CO} 2 emissions aspect of {LCA} to calculate the embodied {CO} 2 of network assets in relation to the operational grid {CO} 2 over time. Several functional units are defined: {CO} 2 per operational year, {CO} 2 per asset cost, {CO} 2 per functional unit of electricity (kW h) and the relationship between embodied emissions and operational emissions in an electricity system over time. Hybrid functional units are then applied in order to better attribute the embodied carbon to the network functions. The hybrid functional units involve network asset lifetime and the issue of temporal horizons. Several suitable horizons are suggested and the comparison of results highlight the importance of the timeframe on results. The relationship between temporal horizons and environmental discounting is discussed and recommendations are made on the appropriate level of discounting depending on the temporal horizon and the purpose of the LCA. The paper uses data from the Great Britain electricity system where planned investment in network assets is £12bn at distribution level (Dx) and £16.4bn at transmission level (Tx) over the next eight years. By using {GB} network data for embodied carbon, demand and asset data, as well as data from the decarbonisation of electricity generation, indicative results are provided into the way in which embodied carbon impacts could change over time, showing that by 2035, the embodied carbon of the transmission network could contribute almost 25 of total emissions associated with electricity. On a regional basis, {DNO} level network assets could reach anywhere between 40 and 130. This network data is also used to show that new network investment could account for up to 6.5 of {DNO} level network embodied carbon when front loaded during the RIIO-ED1 period

Bond graph models of DC-DC converters operating in both CCM and DCM

In this paper, Bond Graphs are employed to develop a novel mathematical model of conventional switched-mode DC-DC converters valid for both continuous and discontinuous conduction modes. A unique causality bond graph model of hybrid models is suggested with the operation of the switch and the diode to be represented by a Modulated Transformer with a binary input and a resistor with fixed conductance causality. The operation of the diode is controlled using an if-then function within the model. The extracted hybrid model is implemented on a Boost and Buck converter with their operations to change from CCM to DCM and to return to CCM. The vector fields of the models show validity in a wide operation area and comparison with the simulation of the converters using PSPICE reveals high accuracy of the proposed model, with the Normalised Root Means Square Error and the Maximum Absolute Error remaining adequately low. The model is also experimentally tested on a Buck topology

Analytical calculation of resonant inductance for zero voltage switching in phase-shifted full-bridge converters

The phase shift full bridge (PSFB) converter allows high efficiency power conversion at high frequencies through zero voltage switching (ZVS); the parasitic drain-to-source capacitance of the MOSFET is discharged by a resonant inductance before the switch is gated resulting in near zero turn-on switching losses. Typically, an extra inductance is added to the leakage inductance of a transformer to form the resonant inductance necessary to charge and discharge the parasitic capacitances of the PSFB converter. However, many PSFB models do not consider the effects of the magnetizing inductance or dead-time in selecting the resonant inductance required to achieve ZVS. The choice of resonant inductance is crucial to the ZVS operation of the PSFB converter. Incorrectly sized resonant inductance will not achieve ZVS or will limit the load regulation ability of the converter. This paper presents a unique and accurate equation for calculating the resonant inductance required to achieve ZVS over a wide load range incorporating the effects of the magnetizing inductance and dead-time. The derived equations are validated against PSPICE simulations of a PSFB converter and extensive hardware experimentations

Investigation of High-Efficiency Wireless Power Transfer Criteria of Resonantly-Coupled Loops and Dipoles through Analysis of the Figure of Merit

The efficiency of a Wireless Power Transfer (WPT) system is greatly dependent on both the geometry and operating frequency of the transmitting and receiving structures. By using Coupled Mode Theory (CMT), the figure of merit is calculated for resonantly-coupled loop and dipole systems. An in-depth analysis of the figure of merit is performed with respect to the key geometric parameters of the loops and dipoles, along with the resonant frequency, in order to identify the key relationships leading to high-efficiency WPT. For systems consisting of two identical single-turn loops, it is shown that the choice of both the loop radius and resonant frequency are essential in achieving high-efficiency WPT. For the dipole geometries studied, it is shown that the choice of length is largely irrelevant and that as a result of their capacitive nature, low-MHz frequency dipoles are able to produce significantly higher figures of merit than those of the loops considered. The results of the figure of merit analysis are used to propose and subsequently compare two mid-range loop and dipole WPT systems of equal size and operating frequency, where it is shown that the dipole system is able to achieve higher efficiencies than the loop system of the distance range examine

Taxing Cars With Attitude

It is now becoming clear that the ACEA (European Automobile Manufacturers' Association) CO2 voluntary agreement for a reduction to 140 g/km for 2008-2009 is unlikely to be met. Furthermore, delivering the target of 120 g/km by 2012 now looks improbable. Although pressure for mandatory regulation grows, for a limited time there remains an opportunity to increase the effectiveness of existing consumer price signals to encourage the uptake of low carbon cars. This paper proposes a new approach to designing an effective low carbon taxation regime. This is to start by identifying the most accessible attitudinal levers with which to modify consumer behaviour. This achieved, a taxation system is then devised to influence attitudes and behaviour to maximum effect. In this way, the attitude-action gap is bridged, exploiting the most efficient links between tax policy, consumer attitudes, car purchasing behaviour and carbon impact