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As shown title, the present paper presents an experimental study on cooling microprocessors with micro channel heat exchangers. A testing bench was necessary to design. The originality of the solution to achieve the cooling mode of the microprocessor. As a heat source it was used a computer whose microchip was placed in maximum heat load using a specialized program. The results obtained from the test...
In this paper the influence of the multi-core architecture on the processing time for solving a 2D problem, described by a non homogenous Poisson PDE, in COMSOL, was considered. Only the direct solvers were taken into account. Different levels of mesh refinement were compared and different Lagrange finite element orders have been used.
The paper presents the automatic control of aircraft in the longitudinal (vertical) plane during landing, taking into account the atmospheric turbulences. The presented structure of automatic landing system consists of two coupled automatic control systems: the former is used for the control of aircraft longitudinal velocity, while the latter performs the control of the flight altitude by means of...
Between a human person, who can be electrostatically charged at voltages of 10–15kV, and an electronic device (computer, laptop, memory stick, tablet, mobile phone, etc.), a system connected to grounding, an electrostatic discharge can occur due to the person's electric load charge (electrification), wearing clothes made of synthetic fibres, due to friction with the air. Electrical discharges due...
This paper summarizes the results of a three-phase load flow analysis case study. This work was part of an overall energy systems modeling and analysis effort designed to develop a validated power flow study that facilitates understanding of power flow concepts for the present distribution networks operating in asymmetry conditions. To simplify data collection requirements and illustrate key concepts,...
The international guidelines (including European Directive 2013/35/EU) set out limits for limb contact currents in the frequency up to 110 MHz, in order to protect workers against the indirect effects of exposure to electromagnetic field. The aim of the study was to analyse the practical role of that kind of metric for an evaluation of the electromagnetic hazards at the workplace. For the practical...
The Distributed Generation (DG) systems of today face a multitude of problems, among which the pollutant emissions and the energy efficiency play a key role. In this sense, the study of optimal operation strategies for such systems becomes highly important. Thus, the purpose of this work will be to investigate using the Nondominated Sorting Genetic Algorithm II (NSGA II) the operation of a 4 gas microturbine...
This paper presents numerical simulation results of a passive magnetic bearing (PMB) used in Flywheel Energy Storage Systems FESS. The magnetic design, the modal analysis, aimed to outline the first six eigenmodes, and a kinetic analysis for the PMB with and without radial eccentricity are presented. These methods and results are valuable in the design phase of the PMB, for sizing its main parameters.
In a world of continuous changes, environmental protection and energy conservation are becoming real concerns. The development of renewable energy technology has taken on an accelerated pace to fulfill these needs. Wind energy conversion has been considered to be one of the most promising renewable energy, owing to its fast developing technology. In the present paper, three-phase 12/8 switched reluctance...
Achieving a high-level of stability represents one major concern in autonomous microgrids (MGs) with high penetration levels of renewable energy sources. The aim of this paper is to study how photovoltaic (PV) power plants can provide dynamic frequency support in an MG, in order to obtain an improved stability for the entire power system. On the PV side an energy storage subsystem is added, which...
This paper presents the topic of manufacturing the stator winding for small induction motors of aluminium instead of copper. The aspect of replacing the material is presented from the perspective of the producer. It is important to obtain a new motor with the same characteristics and the same energy efficiency while decreasing conductor material price and thus the price per motor unit. For these purpose...
In this paper we will made a study of the dynamics of Chua's circuit system from the Hamilton-Poisson geometry point of view. Using MAPLE 15 it is analyzed the phase portrait for some specific values of parameters.
Sometimes, the motor parameters provided by a producer in a datasheet can be slightly different from the parameter values of an acquired motor. The paper presents some identification methods of an interior permanent magnet synchronous motor: when the motor is in idle running or when a load is provided by a servo-motor connected in the same shaft. Specific tests were conducted in order to precisely...
The recent advances in computer aided design (CAD) modeling of electromagnetic field distribution in high voltage (HV) substation are presented in this paper. The substation constitutive components (e.g. towers, breakers, circuit conductors, bus bars, transformers, etc.) were built-up by the authors as three dimensional (3D) CAD models and stored in a data base under the SolidWorks CAD environment...
The limits for limb contact currents noted at the workplace exposed to electromagnetic fields with a frequency up to 110MHz have been set out by international guidelines (including European Directive 2013/35/EU) to protect workers against the indirect effects of exposure. The aim of this study was to analyse what level of limb currents exceed the perception threshold in the intermediate- and radio-frequency...
For easy removal of cylindrical items from the shaft, they are heated on their external cylindrical surface for thermal expansion. The best result is obtained if the temperature drop is highest on the separation from shaft air layer. In the paper, considering a suddenly occurring constant high temperature on the external cylindrical surface of the homogeneous item and the shaft with the same thermal...
This paper presents several main steps to design and prototype a traveling wave (TW) piezoelectric ultrasound motor (PZUM) for outer space applications. The TW-PZUM stator is a radially polarized PZ cylinder, divided into eight angular sectors, which are powered with a pulse width modulated (PWM) power stage that delivers two harmonic, opposite phased voltages. As will be shown, this powering scheme...
This paper is concerned with the analytic solution, in the order of magnitude sense, of the mathematical models that describes the electokinetic and magnetic fields within an electromagnetic microactuator of cantilever type. The nondimensional form of the mathematical model is derived. To this aim, reference quantities are identified. Then the physical quantities and the mathematical model are scaled...
This paper approaches the electromagnetic design and finite-element analysis of a radial flux NdFeB permanent magnet synchronous machine for use as direct-driven generator with low speed micro-wind turbines. The design evaluation of the radial-flux spoke-type permanent magnet (RFPM) generator, based on 2-D and 3-D finite element field analysis, proves that this topology represents a good-performance...
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