Fair charging strategies for EVs connected to a low-voltage distribution network

The development of smart grid technologies and appropriate charging strategies are key to accommodating large numbers of Electric Vehicles (EV) charging on the grid. In this paper a general framework is presented for formulating the EV charging optimization problem and three different charging strategies are investigated and compared from the perspective of charging fairness while taking into account power system constraints. Two strategies are based on distributed algorithms, namely, Additive Increase and Multiplicative Decrease (AIMD), and Distributed Price-Feedback (DPF), while the third is an ideal centralized solution used to benchmark performance. The algorithms are evaluated using a simulation of a typical residential low voltage distribution network with 50% EV penetration. © 2013 IEEE.

Investigation of AIMD based charging strategies for EVs connected to a low-voltage distribution network

In this paper we consider charging strategies that mitigate the impact of domestic charging of EVs on low-voltage distribution networks and which seek to reduce peak power by responding to time-ofday pricing. The strategies are based on the distributed Additive Increase and Multiplicative Decrease (AIMD) charging algorithms proposed in [5]. The strategies are evaluated using simulations conducted on a custom OpenDSS-Matlab platform for a typical low voltage residential feeder network. Results show that by using AIMD based smart charging 50% EV penetration can be accommodated on our test network, compared to only 10% with uncontrolled charging, without needing to reinforce existing network infrastructure. © Springer-Verlag Berlin Heidelberg 2013.

On-off based charging strategies for EVs connected to a Low Voltage distributon network

The development of appropriate Electric Vehicle (EV) charging strategies has been identified as an effective way to accommodate an increasing number of EVs on Low Voltage (LV) distribution networks. Most research studies to date assume that future charging facilities will be capable of regulating charge rates continuously, while very few papers consider the more realistic situation of EV chargers that support only on-off charging functionality. In this work, a distributed charging algorithm applicable to on-off based charging systems is presented. Then, a modified version of the algorithm is proposed to incorporate real power system constraints. Both algorithms are compared with uncontrolled and centralized charging strategies from the perspective of both utilities and customers. © 2013 IEEE.

Enhanced AIMD based decentralized residential charging of EVs

Moving from combustion engine to electric vehicle (EV)-based transport is recognized as having a major role to play in reducing pollution, combating climate change and improving energy security. However, the introduction of EVs poses major challenges for power system operation. With increasing penetration of EVs, uncontrolled coincident charging may overload the grid and substantially increase peak power requirements. Developing smart grid technologies and appropriate charging strategies to support the role out of EVs is therefore a high priority. In this paper, we investigate the effectiveness of distributed additive increase and multiplicative decrease (AIMD) charging algorithms, as proposed by Stu¨dli et al. in 2012, at mitigating the impact of domestic charging of EVs on low-voltage distribution networks. In particular, a number of enhancements to the basic AIMD implementation are introduced to enable local power system infrastructure and voltage level constraints to be taken into account and to reduce peak power requirements. The enhanced AIMD EV charging strategies are evaluated using power system simulations for a typical low-voltage residential feeder network in Ireland. Results show that by using the proposed AIMD-based smart charging algorithms, 50% EV penetration can be accommodated, compared with only 10% with uncontrolled charging, without exceeding network infrastructure constraints.

Distributed Consensus Charging for Current Unbalance Reduction

Electric Vehicle (EV) technology has developed rapidly in recent years, with the result that increasing levels of EV penetration are expected on electrical grids in the near future. The increasing electricity demand due to EVs is expected to provide many challenges for grid companies, and it is expected that it will be necessary to reinforce the current electrical grid infrastructure to cater for increasing loads at distribution level. However, by harnessing the power of Vehicle to Grid (V2G) technologies, groups of EVs could be harnessed to provide ancillary services to the grid. Current unbalance occurs at distribution level when currents are unbalanced between each of the phases. In this paper a distributed consensus algorithm is used to coordinate EV charging in order to minimise current unbalance. Simulation results demonstrate that the proposed algorithm is effective in rebalancing phase currents.

Manganese Superoxide Dismutase Is a Promising Target for Enhancing Chemosensitivity of Basal-Like Breast Carcinoma

AIMS: Although earlier reports highlighted a tumor suppressor role for manganese superoxide dismutase (MnSOD), recent evidence indicates increased expression in a variety of human cancers including aggressive breast carcinoma. In the present article, we hypothesized that MnSOD expression is significantly amplified in the aggressive breast carcinoma basal subtype, and targeting MnSOD could be an attractive strategy for enhancing chemosensitivity of this highly aggressive breast cancer subtype.

RESULTS: Using MDA-MB-231 and BT549 as a model of basal breast cancer cell lines, we show that knockdown of MnSOD decreased the colony-forming ability and sensitized the cells to drug-induced cell death, while drug resistance was associated with increased MnSOD expression. In an attempt to develop a clinically relevant approach to down-regulate MnSOD expression in patients with basal breast carcinoma, we employed activation of the peroxisome proliferator-activated receptor gamma (PPARγ) to repress MnSOD expression; PPARγ activation significantly reduced MnSOD expression, increased chemosensitivity, and inhibited tumor growth. Moreover, as a proof of concept for the clinical use of PPARγ agonists to decrease MnSOD expression, biopsies derived from breast cancer patients who had received synthetic PPARγ ligands as anti-diabetic therapy had significantly reduced MnSOD expression. Finally, we provide evidence to implicate peroxynitrite as the mechanism involved in the increased sensitivity to chemotherapy induced by MnSOD repression.

INNOVATION AND CONCLUSION: These data provide evidence to link increased MnSOD expression with the aggressive basal breast cancer, and underscore the judicious use of PPARγ ligands for specifically down-regulating MnSOD to increase the chemosensitivity of this subtype of breast carcinoma.

Enhanced target detection in clutter using dispersive delay lines and time reversal

On the basis of the technique of time reversal (TR), a new method for low dielectric contrast target detection in clutter by adding dispersive delay lines (DDLs) to each element of the TR mirror (TRM) is proposed. When compared with a conventional TR system, the proposed method improves refocusing to a target by reducing the impact of other scatterers in the environment. The proposed method makes it unnecessary to estimate the position of the target and removes the need for subsequent subtraction as traditionally required. Theoretical and numerical simulated results demonstrate the proposed method.

New SR drive with integrated charging capacity for plug-in hybrid electric vehicles (PHEVs)

Plug-in hybrid electric vehicles (PHEVs) provide much promise in reducing greenhouse gas emissions and, thus, are a focal point of research and development. Existing on-board charging capacity is effective but requires the use of several power conversion devices and power converters, which reduce reliability and cost efficiency. This paper presents a novel three-phase switched reluctance (SR) motor drive with integrated charging functions (including internal combustion engine and grid charging). The electrical energy flow within the drivetrain is controlled by a power electronic converter with less power switching devices and magnetic devices. It allows the desired energy conversion between the engine generator, the battery, and the SR motor under different operation modes. Battery-charging techniques are developed to operate under both motor-driving mode and standstill-charging mode. During the magnetization mode, the machine's phase windings are energized by the dc-link voltage. The power converter and the machine phase windings are controlled with a three-phase relay to enable the use of the ac-dc rectifier. The power converter can work as a buck-boost-type or a buck-type dc-dc converter for charging the battery. Simulation results in MATLAB/Simulink and experiments on a 3-kW SR motor validate the effectiveness of the proposed technologies, which may have significant economic implications and improve the PHEVs' market acceptance

Enhancing Linear Programming with Motion Modeling for Multi-target Tracking

In this paper we extend the minimum-cost network flow approach to multi-target tracking, by incorporating a motion model, allowing the tracker to better cope with longterm occlusions and missed detections. In our new method, the tracking problem is solved iteratively: Firstly, an initial tracking solution is found without the help of motion information. Given this initial set of tracklets, the motion at each detection is estimated, and used to refine the tracking solution.
Finally, special edges are added to the tracking graph, allowing a further revised tracking solution to be found, where distant tracklets may be linked based on motion similarity. Our system has been tested on the PETS S2.L1 and Oxford town-center sequences, outperforming the baseline system, and achieving results comparable with the current state of the art.

New design of a multi-jet target for quasi phase matching

An improved dual-gas quasi-phase matching (QPM) foil target for high harmonic generation (HHG) is presented. The target can be setup with 12 individual gas inlets each feeding multiple nozzles separated by a minimum distance of 10 μm. Three-dimensional gas density profiles of these jets were measured using a Mach-Zehnder Interferometer. These measurements reveal how the jets influence the density of gas in adjacent jets and how this leads to increased local gas densities. The analysis shows that the gas profiles of the jets are well defined up to a distance of about 300 μm from the orifice. This target design offers experimental flexibility, not only for HHG/QPM investigations, but also for a wide range of experiments due to the large number of possible jet configurations. We demonstrate the application to controlled phase tuning in the extreme ultraviolet using a 1 kHz-10 mJ-30 fs-laser system where interference between two jets in the spectral range from 17 to 30 nm was observed.

Evidence of locally enhanced target heating due to instabilities of counter-streaming fast electron beams

The high-current fast electron beams generated in high-intensity laser-solid interactions require the onset of a balancing return current in order to propagate in the target material. Such a system of counter-streaming electron currents is unstable to a variety of instabilities such as the current-filamentation instability and the two-stream instability. An experimental study aimed at investigating the role of instabilities in a system of symmetrical counter-propagating fast electron beams is presented here for the first time. The fast electron beams are generated by double-sided laser-irradiation of a layered target foil at laser intensities above 10(19) W/cm(2). High-resolution X-ray spectroscopy of the emission from the central Ti layer shows that locally enhanced energy deposition is indeed achieved in the case of counter-propagating fast electron beams

Spitzer observations of the asteroid-comet transition object and potential spacecraft target 107P (4015) Wilson-Harrington

Context: Near-Earth asteroid-comet transition object 107P/ (4015) Wilson-Harrington is a possible target of the joint European Space Agency (ESA) and Japanese Aerospace Exploration Agency (JAXA) Marco Polo sample return mission. Physical studies of this object are relevant to this mission, and also to understanding its asteroidal or cometary nature. Aims: Our aim is to obtain significant new constraints on the surface thermal properties of this object. Methods: We present mid-infrared photometry in two filters (16 and 22 μm) obtained with NASA's Spitzer Space Telescope on February 12, 2007, and results from the application of the Near Earth Asteroid Thermal Model (NEATM). We obtained high S/N in two mid-IR bands allowing accurate measurements of its thermal emission. Results: We obtain a well constrained beaming parameter (η = 1.39±0.26) and obtain a diameter and geometric albedo of D = 3.46±0.32 km, and pV = 0.059±0.011. We also obtain similar results when we apply this best-fitting thermal model to single-band mid-IR photometry reported by Campins et al. (1995, P&SS, 43, 733), Kraemer et al. (2005, AJ, 130, 2363) and Reach et al. (2007, Icarus, 191, 298). Conclusions: The albedo of 4015 Wilson-Harrington is low, consistent with those of comet nuclei and primitive C-, P-, D-type asteorids. We establish a rough lower limit for the thermal inertia of W-H of 60 Jm-2s-0.5 K-1 when it is at r = 1 AU, which is slightly over the limit of 30 Jm-2 s-0.5 K-1 derived by Groussin et al. (2009, Icarus, 199, 568) for the thermal inertia of the nucleus of comet 22P/Kopff.

ESO observations of the Nucleus of Rosetta Target 67P/C-G

Rosetta is ESA's new comet orbiter mission, launched in March 2004 and currently en route to Jupiter-family comet 67P/Churyumov-Gerasimenko. The probe will rendezvous with the comet in 2014 and remain in orbit around the nucleus for on-going detailed physical and compositional analysis. Pre-encounter observations of the target are important for characterization of the heliocentric light-curve behaviour and the physical properties of the nucleus, information that is critical for mission planning. The nucleus was first characterized using HST observations in 2003 (Lamy et al. 2006) and observed directly in May 2005 by ground based telescopes (Lowry et al. 2006) when it was at 5.6 AU from the Sun. An extensive database of nucleus observations have since been acquired, not only from large ground-based telescopes like the ESO VLT (Tubiana et al. 2008 & 2011), but also from Spitzer (Kelley et al. 2006 & 2009; Lamy et al. 2008).