1,721,079 research outputs found
Rete di sensori plug-n-play basata sui servizi web: applicazioni al controllo di processi industriali
No full text
Analysis of PEM Fuel Cell - Supercapacitor - Battery Pack System During Standard Cycle
No full textToday the application of PEM (Polymer
Electrolyte Membrane) fuel cell stack in the automotive field
is a topic on central interest. Unfortunately, a PEM fuel cell
stack cannot directly supply variable speed drives because of
their non-linear behaviour in dynamic conditions. This
paper is mostly concerned with the sizing of the supply
system, PEM fuel cell-supercapacitor-battery pack, of an
electric vehicle, based on the urban/suburban drive cycle
NEDC (New European Driving Cycle). The average
required power is used to design the fuel cell stack by
imposing a preset operating point; the battery capacity is
chosen in order to satisfy the constrain on the minimum
value of the state of charge during the cycle; finally, the
supercapacitor is determined by imposing the current
sharing between battery and supercapacitor in transient
condition
An Automatic Measurement System for the Performance Evaluation of Medium-sized and Large Photovoltaic Plants
No full text"In recent years renewable sources of power are being increasingly exploited to address the challenges of climate. change and fossil fuel depletion. Wind power and solar power are two of the few renewable energy sources. capable of rapidly satisfying a reasonable proportion of future energy requirements [1].. Acceptance testing of medium-sized and large photovoltaic (PV) plants requires functional tests executed to. verify the proper working and energy efficiency. A final certificate ensures the compliance with the technical. requirements, as required by Italian Conto Energia program. Tests must be conducted according to several. technical norms. The paper describes a measurement system, implemented for testing medium-sized PV plants in. full compliance with the international standards; moreover, the measurement system can be configured to. measure additional parameters, because it is software based. The measurement system has been adopted for the. performance evaluation of a 842 kWp PV plant, with satisfactory results.
Stazione di misura per il test di un sistema elettromeccanico fault tolerant per la movimentazione di flap di aeromobili
No full textSistema a basso costo per la misura ad ultrasuoni della velocità e della direzione del vento
No full textApparatus for on-line continuous diagnosis of induction motors based on the SFRA technique
No full textThe induction motor is used the most in industrial
applications. In these areas, motor faults can involve several
issues concerning health, safety, and process down time, in addition
to the bare cost of the machinery itself. Induction motors may
have different types of faults, mainly in the stator windings. These
often begin as simple turn-to-turn failures, which can then lead to
worst phase-to-phase or phase-to-ground failures. In the complex
scenario of diagnostic techniques available today, the sweep
frequency response analysis (SFRA) has recently emerged as a
promising approach for the characterization of rotating electrical
machines. In this article, a PC-based, low-cost test system that
implements the SFRA technique is proposed, to verify its applicability
for the continuous online diagnostic of induction motors.
The system performances have been experimentally evaluated,
by testing two 5.5-kW induction motors, with two-and four-poles.
Both the heating test at constant mechanical load and the test at
thermal equilibrium with variable loads have been investigated.
The positive results obtained seem to confirm the applicability
of the proposed system for the online diagnosis of asynchronous
motors
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