Adam Walker

A topology selection consideration of electrical machines for traction applications: towards the FreedomCar 2020 targets

This paper details a qualitative comparison between different types of electrical machine for hybrid electric vehicle traction applications. Targets set by the US Department of Energy for the year 2020 are used as goals. Several types of machine for this application will be discussed, focusing on the benefits and challenges of each machine when applied to these targets. Then the machines are compared based on appropriate quality indices relative to general performance characteristics. It is shown that the interior permanent magnet machine is the most suited topology for traction applications with these challenging targets. Two machine designs for these targets are briefly compared at the end of the paper.

Design considerations for high performance traction machines: Aiming for the FreedomCar 2020 targets

This paper presents considerations for the design of high performance, interior permanent magnet machines for traction applications. These machines will be designed to reach the FreedomCar 2020 targets set by the US Department of Energy for the year 2020 for traction machines, considering both concentrated and distributed wound designs. The paper presents a trade-off study of a wide range of motor designs with the main focus on the number of rotor poles and stator slots. The results from this investigation are then used to achieve an optimal design in terms of the target requirements, as these are introduced in a logical sequence.

CognitiveCharge: Disconnection tolerant adaptive collaborative and predictive vehicular charging

Electric vehicles (EVs) are rapidly becoming more common and ownership is set to rise globally in coming years. The potential impacts of increased EVs on the electrical grid have been widely investigated and in its current state, existing grid infrastructure will struggle to meet the high demands at peak charging hours. The limited range of electric cars compounds this issue. We therefore propose CognitiveCharge, a novel approach to predictive and adaptive disconnection aware opportunistic energy discovery and transfer for the smart vehicular charging. CognitiveCharge detects and reacts to individual nodes and network regions which are at risk of getting depleted by using implicit predictive hybrid contact and resources congestion heuristics. CognitiveCharge exploits localised relative utility based approach to adaptively offload the energy from parts of the network with energy surplus to depleting areas with non-uniform depletion rates. We evaluate CognitiveCharge using a multi-day traces for the city of San Francisco, USA and Nottingham, UK to compare against existing infrastructure across a range of metrics. CognitiveCharge successfully eliminates congestion at both ad hoc and infrastructure charging points, reduces the time that a vehicle must wait to charge from the point at which it identifies as being in need of energy, and drastically reduces the total number of nodes in need of energy over the evaluation period.

GPSR-TARS: Congestion aware geographically targeted remote surveillance for VANETs

Video over vehicular networks continues to receive warranted attention, with envisioned applications having the potential to present entirely new opportunities and revolutionise existing services. Many video systems have been proposed, ranging from safety to advertising. We propose a novel system for VANETs, namely the TArgeted Remote Surveillance (TARS) module for the existing Greedy Perimeter Stateless Routing (GPSR) protocol which permits multiple mobile vehicles to request and receive live video feeds from vehicles within a select geographic region. The multi-hop, vehicle-to-vehicle system enables mobile units to surveil a target area in real time by leveraging the dashboard cameras of vehicles moving within the target region. We combine several proposed extensions to the core protocol to introduce a dynamic real time congestion aware clustering scheme to achieve this. Our proposed system is compared against existing routing protocols using mobility data from Nottingham. GPSR-TARS outperforms the protocols assessed in key criteria crucial for meeting the quality of service demands of live multimedia dissemination.

Development and design of a high performance traction machine for the FreedomCar 2020 traction machine targets

This paper details the design process of a high performance electrical machine with the objective of achieving US Department of Energy FreedomCar 2020 targets, namely meeting the high speed efficiency requirement without sacrificing performance elsewhere. The FreedomCar targets are detailed, with a short discussion of the challenges involved. All feasible machine topologies are considered, and qualitatively compared in order to identify the best candidate topologies. A set of potential technologies and topologies are evaluated to establish the primary geometry specifications, such as slot pole combination, winding layout and active length. Optimisation methods are then implemented to establish the more detailed geometrical parameters, e.g. tooth width and slot depth. Finally a conclusive design is presented with the finite element simulation results. The design meets all the performance requirements of the targets.