Analysis of the strategies for managing extended-range electric vehicle powertrain in the urban driving cycle

Introduction. An Extended-Range Electric Vehicle (EREV) is a type of electric vehicle that uses an additional internal combustion engine (ICE) to charge the battery in order to provide the vehicle with a greater range than in electric only mode. Purpose. Analysis and comparison of the performance of EREV powertrain managed according to three control strategies: pure electric mode, hybrid mode with ICE constantly working, and hybrid mode with ICE working only at high power demand. Methods. The tests were carried out using a laboratory test stand that represented the structure of EREV powertrain. Liquefied petroleum gas was used as a fuel to supply the ICE. The test conditions were defined by a special driving cycle simulating urban driving. Results. Time series plots of selected parameters of electric motor, electrochemical battery pack, range extender generator and active load system. Practical value. Among the considered control strategies of EREV powertrain, the energy balance of the electrochemical battery is negative for a purely electric mode, significantly positive for continuous range extenders (REXs) operation mode and moderately positive for the mode with REX activation only in dynamic states.Вступ. Електромобіль зі збільшеним запасом ходу (ЕЗЗХ) – це тип електромобіля, який використовує додатковий двигун внутрішнього згоряння (ДВЗ) для заряджання акумулятора, щоб забезпечити транспортний засіб більшим запасом ходу, ніж у режимі лише на електричному ходу. Мета. Аналіз та порівняння ефективності силової передачі ЕЗЗХ, керованої відповідно до трьох стратегій управління: чисто електричний режим, гібридний режим з постійно працюючим ДВЗ та гібридний режим з ДВЗ, що працює тільки при високому споживанні потужності. Методи. Випробування проводилися на лабораторному стенді, що представляє собою конструкцію силової передачі ЕЗЗХ. Скраплений газ використовувався як паливо для живлення ДВЗ. Умови випробувань визначалися спеціальним циклом водіння, що імітує водіння в умовах міста. Результати. Графіки часових рядів вибраних параметрів електродвигуна, електрохімічної акумуляторної батареї, генератора-розширювача діапазону та системи активного навантаження. Практична цінність. Серед розглянутих стратегій керування силовою установкою ЕЗЗХ, баланс енергії електрохімічної батареї негативний для чисто електричного режиму, суттєво позитивний для режиму роботи розширювачів діапазону (РД) та помірно позитивний для режиму з активацією РД лише у динамічних станах

ADM-like Hamiltonian formulation of gravity in the teleparallel geometry

We present a new Hamiltonian formulation of the Teleparallel Equivalent of General Relativity (TEGR) meant to serve as the departure point for canonical quantization of the theory. TEGR is considered here as a theory of a cotetrad field on a spacetime. The Hamiltonian formulation is derived by means of an ADM-like 3+1 decomposition of the field and without any gauge fixing. A complete set of constraints on the phase space and their algebra are presented. The formulation is described in terms of differential forms.Comment: 43 pages, LaTeX2e; the original 73 page paper arXiv:1111.5498v1 was revised and divided into two parts. The present paper is the first part of the original one (the second part is available as arXiv:1309.4685

Chiral fermions and torsion in the early Universe

Torsion arising from fermionic matter in the Einstein-Cartan formulation of general relativity is considered in the context of Robertson-Walker geometries and the early Universe. An ambiguity in the way torsion arising from hot fermionic matter in chiral models should be implemented is highlighted and discussed. In one interpretation, chemical potentials in chiral models can contribute to the Friedmann equation and give a negative contribution to the energy density.Comment: 5 pages revtex4; error in v1 corrected

Organizacja pracy poczty. Przegląd Zagadnień Łączności, 1963, nr 9 (24)

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Perfect hypermomentum fluid: variational theory and equations of motion

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Semi-Teleparallel Theories of Gravitation

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Gravitational Lorentz Force and the Description of the Gravitational Interaction

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Big bounce from spin and torsion

The Einstein-Cartan-Sciama-Kibble theory of gravity naturally extends general relativity to account for the intrinsic spin of matter. Spacetime torsion, generated by spin of Dirac fields, induces gravitational repulsion in fermionic matter at extremely high densities and prevents the formation of singularities. Accordingly, the big bang is replaced by a bounce that occurred when the energy density $\epsilon\propto gT^4$ was on the order of $n^2/m_\textrm{Pl}^2$ (in natural units), where $n\propto gT^3$ is the fermion number density and $g$ is the number of thermal degrees of freedom. If the early Universe contained only the known standard-model particles ($g\approx 100$), then the energy density at the big bounce was about 15 times larger than the Planck energy. The minimum scale factor of the Universe (at the bounce) was about $10^{32}$ times smaller than its present value, giving \approx 50 \mum. If more fermions existed in the early Universe, then the spin-torsion coupling causes a bounce at a lower energy and larger scale factor. Recent observations of high-energy photons from gamma-ray bursts indicate that spacetime may behave classically even at scales below the Planck length, supporting the classical spin-torsion mechanism of the big bounce. Such a classical bounce prevents the matter in the contracting Universe from reaching the conditions at which a quantum bounce could possibly occur.Comment: 6 pages; published versio