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Bucharest, Romania

Jivan C.,Icpe | Hanek M.,Center 6 Energie
Electrotehnica, Electronica, Automatica | Year: 2013

The paper presents an analysis of the power quality in a trader with special technological equipment that requires continuous power. We found very high levels of capacitance energy injected in the electric network, confirmed also by the electric energy bills. After the recorded tests and measurements, we found the generating sources, namely the three power supplies UPS, each of 250 kVA capacity. To remedy this problem, we proposed a number of measures including the installation of a passive filter (inductive) to compensate the capacitive load. Source

Recent years the world has been in continuous change. This has been caused by the economic crisis. Changes in the external environment of an organization can decisively influence its internal one. A parallel can be drawn between this type of interaction and The Second Principle of thermodynamics, which describes the balance between two environments influencing each other. If an organization's external environment is out of balance, meaning that it has a higher level of entropy, the entropy of its internal environment will increase as well, However, the risk of external instability can become an advantage for an organization that has a working risk management system. A risk management system can control risk, thus transforming it into an asset. Source

Andrei M.-I.,Icpe | Ioan D.,Polytechnic University of Bucharest
Electrotehnica, Electronica, Automatica | Year: 2014

Old modelling methodologies based on Kirchhoff equations are not accurate enough for the nowadays-high frequency integrated circuits applications, due to the electromagnetic field effects. Several lumped circuit compact models were proposed, but the main drawback is inaccuracy at high frequencies. That is why the new methodologies have to consider an electromagnetic analysis. Models resulted from the electromagnetic analysis provide a high accuracy, but with high computational costs. This paper will deal with a comparison between those two approaches, lumped circuit compact models and distributed parameters models, for modelling the integrated inductors. The use of high performance computing for the modelling process will also be discussed. Source

Modreanu N.-M.,Icpe | Andrei M.-I.,Icpe | Morega M.,Polytechnic University of Bucharest
Revue Roumaine des Sciences Techniques Serie Electrotechnique et Energetique | Year: 2014

Permanent magnets brushless DC micro-motors are increasingly used in accurate motion control applications and high precision positioning systems. Main problems concerning their manufacture refer to design accuracy and adequate fabrication technology. The study presented in the paper is based on both numerical analysis and experimental assessment of operating characteristics of such a micro-motor with surface mounted permanent magnets, specially conceived for an application in aerospace technologies. An experimental prototype was manufactured based on inventive design, originally tested and refined by simplified 2D numerical simulation. More realistic 3D models are further developed aiming at the optimization of the motor, according to application specific criteria (high torque, precision in speed control, heating control etc.). The paper presents a 3D reduced model with inclined slots, used in finding an adequate design for the minimization of the cogging torque. Source

Popa I.,Icpe | Stere E.A.,Icpe | Cotescu S.L.,ISPE
Electrotehnica, Electronica, Automatica | Year: 2013

Started twenty years ago, under the aegis of the United Nations, the sustainable development is not strong enough to replace the actual industrial development. However, it remains the single way for the future of humanity. Until now, in spite of programmes and multitude of actions, the real progresses in the field of sustainability are too small. More, the current worldwide situation continually worsens by the number and intensity of crises. Even the General Secretary of UN, recently recognized some of the severe crises of the present. Unfortunately, the sustainable development cannot be applied, without a moral and spiritual reform of the humanity. This paper analyses some of the obstacles in the way of new type of development, by its own features and the negative precedents continually accumulated during the world evolution. Source

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