38,650 research outputs found
Mixed integer nonlinear programming for Joint Coordination of Plug-in Electrical Vehicles Charging and Smart Grid Operations
The problem of joint coordination of plug-in electric vehicles (PEVs)
charging and grid power control is to minimize both PEVs charging cost and
energy generation cost while meeting both residential and PEVs' power demands
and suppressing the potential impact of PEVs integration. A bang-bang PEV
charging strategy is adopted to exploit its simple online implementation, which
requires computation of a mixed integer nonlinear programming problem (MINP) in
binary variables of the PEV charging strategy and continuous variables of the
grid voltages. A new solver for this MINP is proposed. Its efficiency is shown
by numerical simulations.Comment: arXiv admin note: substantial text overlap with arXiv:1802.0445
Drastic improvement of surface structure and current-carrying ability in YBa2Cu3O7 films by introducing multilayered structure
Much smoother surfaces and significantly improved superconducting properties
of relatively thick YBa2Cu3O7 (YBCO) films have been achieved by introducing a
multilayered structure with alternating main YBCO and additional NdBCO layers.
The surface of thick (1 microm) multilayers has almost no holes compared to
YBCO films. Critical current density (Jc) have been drastically increased up to
a factor > 3 in 1 microm multilayered structures compared to YBCO films over
entire temperature and applied magnetic filed range. Moreover, Jc values
measured in thick multilayers are even larger than in much thinner YBCO films.
The Jc and surface improvement have been analysed and attributed to growth
conditions and corresponding structural peculiarities.Comment: Accepted to Appl. Phys. Lett. 88, June (2006), in press 4 pages, 3
figure
Radiation-Induced "Zero-Resistance State" and the Photon Assisted Transport
We demonstrate that the radiation induced "zero-resistance state" observed in
a two-dimensional electron gas is a result of the non-trivial structure of the
density of states of the systems and the photon assisted transport. A toy model
of a structureless quantum tunneling junction where the system has oscillatory
density of states catches most of the important features of the experiments. We
present a generalized Kubo-Greenwood conductivity formula for the photon
assisted transport in a general system, and show essentially the same nature of
the transport anomaly in a uniform system.Comment: 4 pages, 3 figures. Please send comment to [email protected]. This
version added a paragraph to discuss the implication of negative conductanc
Model Predictive Control for Smart Grids with Multiple Electric-Vehicle Charging Stations
Next-generation power grids will likely enable concurrent service for
residences and plug-in electric vehicles (PEVs). While the residence power
demand profile is known and thus can be considered inelastic, the PEVs' power
demand is only known after random PEVs' arrivals. PEV charging scheduling aims
at minimizing the potential impact of the massive integration of PEVs into
power grids to save service costs to customers while power control aims at
minimizing the cost of power generation subject to operating constraints and
meeting demand. The present paper develops a model predictive control (MPC)-
based approach to address the joint PEV charging scheduling and power control
to minimize both PEV charging cost and energy generation cost in meeting both
residence and PEV power demands. Unlike in related works, no assumptions are
made about the probability distribution of PEVs' arrivals, the known PEVs'
future demand, or the unlimited charging capacity of PEVs. The proposed
approach is shown to achieve a globally optimal solution. Numerical results for
IEEE benchmark power grids serving Tesla Model S PEVs show the merit of this
approach
Spin-dependent Andreev reflection tunneling through a quantum dot with intradot spin-flip scattering
We study Andreev reflection (AR) tunneling through a quantum dot (QD)
connected to a ferromagnet and a superconductor, in which the intradot
spin-flip interaction is included. By using the nonequibrium-Green-function
method, the formula of the linear AR conductance is derived at zero
temperature. It is found that competition between the intradot spin-flip
scattering and the tunneling coupling to the leads dominantes resonant
behaviours of the AR conductance versus the gate voltage.A weak spin-flip
scattering leads to a single peak resonance.However, with the spin-flip
scattering strength increasing, the AR conductance will develop into a double
peak resonannce implying a novel structure in the tunneling spectrum of the AR
conductance. Besides, the effect of the spin-dependent tunneling couplings, the
matching of Fermi velocity, and the spin polarization of the ferromagnet on the
AR conductance is eximined in detail.Comment: 14 pages, 4 figure
Properties of nuclei in the nobelium region studied within the covariant, Skyrme, and Gogny energy density functionals
We calculate properties of the ground and excited states of nuclei in the
nobelium region for proton and neutron numbers of 92 <= Z <= 104 and 144 <= N
<= 156, respectively. We use three different energy-density-functional (EDF)
approaches, based on covariant, Skyrme, and Gogny functionals, each within two
different parameter sets. A comparative analysis of the results obtained for
odd-even mass staggerings, quasiparticle spectra, and moments of inertia allows
us to identify single-particle and shell effects that are characteristic to
these different models and to illustrate possible systematic uncertainties
related to using the EDF modellingComment: 43 LaTeX pages, 14 figures, accepted in Nuclear Physics A, Special
Issue on Superheavy Element
- …