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The derivation of analytical solutions for the optimal reference currents during Maximum-Torque-per-Current (MTPC; or Maximum-Torque-per-Ampere (MTPA)), Maximum-Torque-per-Voltage (MTPV) and Maximum-Torque-per-Flux (MTPF) operation of anisotropic synchronous machines with non-negligible stator resistance and mutual inductance is presented. The analytical solutions allow for a direct computation of...
Comparative tests for efficiency of a drive equipped with reluctance synchronous motor and induction motor is the subject of the paper. Efficiency was determined for drives operating with constant torque. Test results indicate that use of the drive equipped with reluctance synchronous motor offer lower consumption of electric power in relation to the drive equipped with induction motor of the same...
One of the major drawbacks of Finite Control Set — Model Predictive Control (FCS — MPC), is the high switching frequency, besides a spread harmonic spectrum. Despite of this, the FCS — MPC provides excellent speed to changes of references and disturbances. In this work we present a control strategy based on FCS — MPC that allows a reduction of the switching frequency in steady state, increasing the...
The article is dedicated to the consideration of an issue of efficiency assessment for enterprises economic activity. the analyze of scientific views of different authors to the problem of enterprises economic efficiency assessment in environmental system is done. The coefficient of environmental management quality based on Delphi technique is developed. the authors propose a new assessment indicator...
The purpose of this study is to obtain power for driving sensors using the magnetic energy harvesting. The magnetic energy harvesting device is constituted with a coil, a full-wave rectifier circuit and a DC-DC step-down converter. In this paper, this device was evaluated to obtain a DC output voltage of 3.3 V. Additionary, a target power for driving sensors was set to 90 mW. As an evaluated result,...
This work presents a research on creation new career opportunities in the electrical engineering education. The new generation of qualified engineers from EU and EU Neighborhood regions will bring up economics not only in Latvia, but also in EU and EU Neighborhood regions. The creation of innovation based training modules for electrical engineers in energy saving technologies in cooperation with Central...
The integration level of electronic systems has continually increased over the past years, leading to significant reductions in cost, size and power consumption of consumer applications. One block, however, is still mostly implemented using discrete components: the Power Management Unit. This paper analyses the benefits of monolithic power management together with the main bottlenecks, and demonstrates...
The paper proposes a method to use the Fibonacci numbers with odd and even indices for synthesis of switched capacitor converters (SCCs) with multiphase control. As in the previously developed method using high-radix positional numeral systems, the capacitors in the proposed method can be connected in parallel. For this purpose, a special two-dimensional (2D) array of switches is introduced. Thus,...
Every company (including machinery manufacturing and construction companies) leads to increase its activities' profitability and to improve quality performance indicators, such as processes operating and safety culture, safety level, human resources satisfaction level, and goodwill. Lean manufacturing and lean construction (derivative of lean manufacturing) enable to reach these goals. The article...
Correct and efficient selection of innovative solutions is the most important part of the whole process of implementation of innovations in small businesses. In this regard, the study of the mechanism for the selection of innovative solutions based on an assessment of efficiency reserves is a vital task. In this article, using analytical methods, systematic approach, logical methods of research are...
Efficiency improvements attainable with permanent magnet motors have been well documented. Some permanent magnet motors have been equipped with an induction cage in the rotor to allow direct on line starting. Designs of this type have been referred to as line start permanent magnet motors. A topic that has not received much attention is the use of this type of motor with an adjustable speed drive...
Industry standards, including IEEE 112, have for many years characterized the component losses of three-phase induction motors as primary and secondary I2R, core, friction and windage, and stray load loss. The definitions of each of the losses, as epitomized in IEEE 112, guarantee that a significant part of the losses will be characterized as stray load loss. It also guarantees that the secondary...
The following paperwork considers a bidirectional series resonant DC-DC converter operating above the resonant frequency with the usual phase-shift control. Its features are discussed. Some of the converter disadvantages are proposed to be compensated by means of a control technique. For this purpose, simultaneous phase-shift and frequency control is applied. The advantages of the proposed solution...
The goal of this paper is to measure the parallel performances using OpenMP for surface gravity waves simulation. Here, the non-hydrostatic model is used to describe the fluid flows. The discretization of pressure, horizontal and vertical velocity are given in staggered grids by Arakawa grids. The numerical simulation of gravity waves with wavelength 100 meters is elaborated. The results are shown...
A set of technologies of aggregation for integrating scalar criteria of estimating the efficiency of on-board computer systems is proposed. They based on homogeneity, weighting coefficients of significance, ranges of changes of particular quality parameters. The model is formed belongs to the class of optimization problems. To solve the problem of choosing the optimal alternative, linear, linear-numerical,...
In this paper we present a finite element analysis routine for modeling of semiconductor Hall sensors. Their efficiency is studied varying the base semiconductor material. More specifically, 2D COMSOL semi-conductor model is initially employed to extract the properties of the conductive channel. Subsequently a 3D COMSOL DC model is used to perform the studies regarding the Hall sensor efficiency....
Design and analysis of a moon slotted circular planar monopole UWB (ultra-wide band) antenna is discussed. The proposed antenna operates within a frequency spectrum of 2.62GHz to 12.63GHz, which includes the unlicensed band 3.1GHz-10.6GHz approved by FCC in 2002. It achieves a maximal peak gain of 4.85dBi at 9.75GHz and highest radiation efficiency of 95.94% at 3.1GHz. This antenna is mounted on a...
Two kinds of RF power combiner are studied. Matched Wilkinson combiner shows very good linearity but low power efficiency. Unmatched Wilkinson combiner used at the output of class-B amplifiers can be optimized in order to obtain the same good linearity of a matched Wilkinson combiner but better efficiency. Careful attention has to pay to the amplifier impedance to stop instability that may create...
This paper deals with the electromagnetic, mechanical, and cooling solutions for an innovative direct-drive suited for steering gears on board ships. The work is comprised in a research project funded by the Italian Navy. The research aims to realize a full-electric and oil-free drive for actuation of hydraulic loads in the perspective of “more green ships”. The electrical drive proposed is based...
The conductive charging method for the electric vehicles is the most widespread, since it is the simplest and has higher returns. In the last years, alternative charging technologies have been investigated. Between these wireless charging systems have been large diffusion and have been commercialized by some manufacturer. Wireless charging systems for electric vehicles have some advantages respect...
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