Now showing 1 - 10 of 48
  • Publication
    A foldable, all-terrain tracked electric wheelchair
    Many existing wheelchairs design are bulky, ugly, slow and confined to flat surfaces. While tracked wheelchairs do exist, such as the Action Trackchair, they are large and expensive (~€10k). Likewise, while folding wheelchairs also exist (see e.g the Zinger) these are often not suited to all-terrain performance. The significance of this project is to harness the technology underpinning the ongoing emergence of urban transport ridables and use this to produce an exciting new wheelchair form factor. A key differentiator is that our tracked platform uses commodity polyvee belting which is standard method for industrial power transmission. This means that our tracks can be simpler and cheaper than more elaborate, custom solutions. The vision is to create a collapsible chair design that exploits the tidy flatness of our platform to allow the whole device to fold down to a briefcase size and shape. Portable and folding wheelchair designs tend to struggle with neatly accommodating the large wheels. As shown in the Appendix, using the flat tracked base platform provides the perfect frame for a chair superstructure to fold into. This will allow the folded-up tracked wheelchair to be stowed in the boot of a car, or easily brought along on the bus or train. Such an affordable and portable device should materially enhance the autonomy and mobility of people with physical disabilities.
      183
  • Publication
    Geospatial Visualisation Techniques for Transmission System Needs Identification: A Case Study with High Shares of Distributed Energy Resources
    This paper presents the principles of a mapping and network visualisation tool in development at the transmission system operator (TSO) of Ireland. Employing a set of Python packages, its intention is to aid planning engineers to explore, understand and communicate power system analysis results by providing more meaningful network diagrams. In order to illustrate the guiding design philosophy, the business process of scenario-based network investment needs identification is used. This process involves building alternative, multi-decadal pathways for the electricity system, which generates a significant volume of data and hence sense-making burden. Given that data-visualisation choices can obfuscate or mislead, how such data is represented can have a bearing on whether actionable insights are garnered. While planning knowledge guides the visual communication, the principles presented should prove useful to the synthesis of any power system subject matter and visualisation; graphic design could be effectively employed when communicating key messages to decision-makers, as ultimately the most important aspects of any analysis must be ​shown. A significant topic in its own right, the application of visualisation techniques in the field of power systems is low compared to other scientific fields. The paper thus proceeds with a treatment of the extant forms of visualisation currently employed by the power systems community. Rationale and notes on the selection of geographic maps and information dashboards as means for visualising power system data – including the multi-dimensional data of distributed energy resources – are then provided.
      179
  • Publication
    All-Island Substation Connectivity Diagram v1.0
    (2018-10-05)
    In 1931, Harry Beck created the iconic London Underground tube map. By distorting the exact geography of the city, and insisting on only 90° or 45° angles, he created a legible display that made the connections between tube stations intuitive and tangible. Notably, it seems Beck’s familiarity with circuit schematics inspired his iconic tube map. With our diagram we try to come full circle: can transit maps inspire a new way to look at the circuits that make up the Irish power system? This diagram was iteratively built up over the course of a nine month collaboration between Dr. Paul Cuffe (UCD) and Dr. Pádraig Daly and others in Eirgrid. A key motivation was to aid communication with non-technical stakeholders: for instance, to explain why it might be necessary to build a new powerline to accommodate more wind power. The main challenge was locating each substation to have a plausible geographic position while also orienting the connecting lines at 90° or 45° (though we had to cheat in places, either by adding inflection points, or by tolerating ‘wrong’ angles) While some node-positioning algorithms were used in the early stages, the bulk of the work here was done manually, with a 45° set square perched up against the screen. Strict geographical accuracy is sacrificed where this allows a cleaner depiction of the system's connective structure. Provided as-is and without warranty.
      217
  • Publication
    Optimization and Visualization Tools for Situational Awareness in Highly Renewable Power Systems
    (IEEE, 2020-10-01)
    This paper proposes new tools for predicting and visualising the plausible near term shifts in branch loading that may arise due to output fluctuations from renewable generators. These tools are proposed to enhance situational awareness for control room operators, by providing early warnings of where bottlenecks may manifest in a transmission system. For predicting plausible branch loading shifts, a linear optimal power flow formulation is presented which uses a novel objective function to characterise the maximum loading a branch could be exposed to in the short term. This analysis therefore identifies which branches could become overloaded due to shifts in output from volatile generators. Equivalently, these branches can be seen as congestion bottlenecks which may cause curtailment of renewable generation. To allow the system operator to maintain awareness of such potentialities, these congestable branches are highlighted on a system diagram which is drawn to explicitly portray the electrical distance between components in the network.
      334Scopus© Citations 3
  • Publication
    A Comparison of Malicious Interdiction Strategies Against Electrical Networks
    (IEEE, 2017-06)
    How well can a typical electrical power system withstand a sophisticated malicious attack undertaken against its exposed branches? The present work seeks to articulate a comprehensive answer to this fundamental question of wide societal importance. New and established techniques that an attacker might use to select promising attack targets are considered, spanning complex network analysis, metaheuristics and classical optimization. By simulating this wide gamut of attack strategies on several test power systems, each modelled under many representative operating states, this work comprehensively articulates the expected robustness of electrical power grids against coordinated branch interdictions.
      719Scopus© Citations 20
  • Publication
    Towards a Blockchain Contract-for-Difference Financial Instrument for Hedging Renewable Electricity Transactions
    (IEEE, 2020-10-01) ;
    Contract-for-Difference financial instruments are available to renewable electricity generators in day-ahead electricity markets to allow them to hedge against revenue risk. Traditional CfDs while designed to hedge revenue risk, introduce other new risks such as counterparty credit, margining and third-party risks. We therefore propose a novel financial instrument - an Ethereum blockchain-based dual escrow smart contract, to serve as the mediator in a CfD agreement between a renewable electricity generator and supplier. This financial instrument addresses hedging related risks that result from traditional CfD agreements in day-ahead electricity markets. In this paper, we design the logic of the financial instrument, translate this logic to smart contract codes and demonstrate its expected performance. Overall, the proposed financial instrument has the benefits of reducing hedging related risks inherent in traditional CfDs. Likewise, it enables secure, efficient, cost-effective, consistent, reliable, transparent and frictionless transactions between contracting parties in a CfD agreement.
      558Scopus© Citations 8
  • Publication
    Design and Test of a Tracked Personal Transportation Device
    (IEEE, 2019-10-17) ;
    A rideable is a small, portable, electric vehicle used to transport an individual in an urban environment. This new class of electric vehicles are perfect for the urban commuter and are rapidly growing in popularity. This is particularly evident from the rapid rise of electric scooter rental companies. However, many available rideables have a number of disadvantages that may be curbing their growth. This has created an opening in the market for a new rideable, that excels in areas where current rideables have shortcomings. This paper presents a new rideable, the TracPerT, which, uniquely, uses tank style tracks rather than conventional wheels for traction and locomotion. This new rideable is designed to deal with the difficulties presented by currently available personal transport devices. Progress on the first powered prototype of the TracPerT is reported.
      473Scopus© Citations 2
  • Publication
    Capability Chart for Distributed Reactive Power Resources
    (Institute of Electrical and Electronics Engineers, 2013-09-11) ; ;
    The ubiquity of synchronous generation should not be assumed in highly renewable power systems. Various problems may consequently arise, not least of which are the difficulties entailed in maintaining regional reactive power balance. Offering a potential solution to such problems, modern renewable generator technologies offer controllable reactive power resources. As many of these generators will be embedded in distribution networks, their incorporation into transmission system operational and planning activities appears challenging. An extension of the capability chart concept offers insight here: for a given active power exchange between the transmission system and a distribution network section, the range of controllable reactive power typically available is of interest. This aggregate capability depends on the innate machine capabilities of the distributed generators and on the prevailing conditions within the distribution network. Novel optimisation techniques are useful in addressing the latter point, offering a means to identify the combination of power flow profiles within the distribution system most restrictive to reactive power provision. The capability chart thus derived gives the dependable range of reactive power available, under the assumption that each generator is operated to locally maximize its own reactive power contribution. Such a description can be applied in transmission system planning or to quantify the effects of modifications to the distribution system.
      1236Scopus© Citations 45
  • Publication
    Towards Embedding Network Usage Charges Within a Peer-to-Peer Electricity Marketplace
    This paper proposes a novel tariff regime for peer-to-peer energy trading, with an aim to increase transmission efficiency and grid stability by penalising long distance power transactions. In this scheme a portion of the transacted energy is withheld based on the electrical distance between buying and selling parties, calculated here according to the Klein Resistance Distance. This tariff regime is simulated using a dataset of producers and consumers over a 24-hour period. First, a notional marketplace equilibrium simulation is performed, in which consumers can optimally activate demand response resources to exploit local availability of energy. Consumers are observed to move some demand away from peak times to make use of local generation availability. These simulated market out-turns are then used as inputs to a time series power flow analysis, in order to evaluate the network’s electrical performance. The regime is found to decrease grid losses and the magnitude of global voltage angle separation. However, the metric whereby taxes are calculated is found to be too skewed in the utility’s favour and may discourage adoption of the peer-to-peer system. The method also attempts to encourage regulatory adoption by existing grid operators and utilities. Some counter-intuitive allocations of tokenised energy occur, owing to specific consumers’ demand profiles and proximity to generators.
      386Scopus© Citations 5