Search results for "TTR"
showing 10 items of 3945 documents
Impact Evaluation of Innovative Selective Harmonic Mitigation Algorithm for Cascaded H-Bridge Inverter on IPMSM Drive Application
2021
This paper presents a detailed analysis of the use of a novel Harmonic Mitigation algorithm for Cascaded H-Bridge Multilevel Inverter in electrical drives for the transportation field. For this purpose, an enhanced mathematical model of Interior Permanent Magnet Synchronous Motor (IPMSM), that takes into account simultaneously saturation, cross-coupling, spatial harmonics, and iron loss effects, has been used. In detail, this model allows estimating accurately the efficiency and the torque ripple of the IPMSM, crucial parameters for transportation applications. Moreover, two traditional pulse width modulation strategies, Sinusoidal Phase-Shifted and Switching Frequency Optimal Phase-Shifted…
Time domain symmetry parameters analysis for series arc fault detection
2022
This paper presents a feasibility study of exploiting the symmetry of some parameters for series arc fault detection in electrical circuits. The considered parameters are defined in the time domain and they are based on the current signal derivative and the evaluation of cross-correlation between subsequent observation windows. The analysis is carried out for AC systems, starting from an experimental characterization, which has been carried out in accordance with the Standard UL 1699 requirements for "unwanted tripping tests"and "operation inhibition tests"of arc fault circuit interrupters (AFCIs). The results obtained in different load conditions show that the proposed parameters can be us…
Performance Improvement of Grid-Integrated Doubly Fed Induction Generator under Asymmetrical and Symmetrical Faults
2023
The doubly fed induction generator (DFIG)-based wind energy conversion system (WECS) suffers from voltage and frequency fluctuations due to the stochastic nature of wind speed as well as nonlinear loads. Moreover, the high penetration of wind energy into the power grid is a challenge for its smooth operation. Hence, symmetrical faults are most intense, inflicting the stator winding to low voltage, disturbing the low-voltage ride-through (LVRT) functionality of a DFIG. The vector control strategy with proportional–integral (PI) controllers was used to control rotor-side converter (RSC) and grid-side converter (GSC) parameters. During a symmetrical fault, however, a series grid-side converter…
Kraftuttryck och tillmälen i serietidningen Kalle Anka
2000
Autonomie locali e politiche pubbliche per l’economia digitale
2019
La rivoluzione digitale ha causato in questi anni un significativo disalli- neamento tra chi subisce le conseguenze delle nuove forme economiche e la distribuzione delle responsabilità regolative tra i diversi attori. Il risultato è che le città sono le più colpite dai cambiamenti in atto, ma non sempre hanno strumenti adeguati a fronteggiare le novità e interpretarle secondo i propri bisogni e necessità. A partire da queste premesse, il presente lavoro analizza l’impatto delle tecnologie digitali sul tessuto socio-economico delle città e ragiona sulle contrapposte esigenze di politiche ritagliate sulle spe- cificità locali e, al contempo, di regole omogenee per il mercato. Su questa inelim…
Recensione a GIORGIO RESTA, AUTONOMIA PRIVATA E DIRITTI DELLA PERSONALITA
2006
Dalla prospettiva del problema relativo allo sfruttamento economico degli attributi immateriali della persona il contributo ripercorre sinteticamente il dibattito sulla disponibilità/indisponibilità dei diritti fondamentali riguardo ai quali è possibile prefigurare la separazione di un elemento (un "quid" nella terminologia di F. Carnelutti) - materiale o immateriale - della persona che possa divenire oggetto di atti di disposizione giuridicamente rilevanti. Si individuano prospettive di indagine significative in una rinnovata considerazione del tema nel quadro della dialettica tra libertà e proprietà, autodeterminazione della persona e affidamento dei terzi, persona e mercato.
Multi-Chip RFID Antenna Integrating Shape-Memory Alloys for Detection of Thermal Thresholds
2011
Low-cost wireless measurement of objects' temperature is one of the greatest expectation of radiofrequency identification technology for the so many applications in cold supply-chain control and safety assessment in general. In this context, the paper proposes a dual-chip UHF tag embedding shape memory alloys (SMA) able to transform the variation of the tagged item's temperature into a permanent change of antenna radiation features. This event-driven antenna is hence able to selectively activate the embedded microchips according to the temperature above or below a given threshold. A general design methodology for the resulting two-ports tag antenna is here introduced and then applied to pro…
A Model for the Study of Sheath Currents in Medium Voltage Cables for Industrial Application
2020
In this paper, the implementation of a simulation model for studying the effect of cross-bonding of metallic sheaths and/or non-magnetic armor of single-core medium voltage cables in the same circuit is discussed. With the use of single-core cables, the resistive losses due to the induced circulating currents in cable sheaths or armors causes an increase of cable temperature that reduces its ampacity. In addition, the risk of electric shock due to induced voltages may be present if a person is exposed to the armor/sheath at the unbounded end. For this reason, special bonding techniques are used to significantly reduce these currents. The authors have implemented a model that could be used t…
La corte del re di Napoli Ferrante I d'Aragona (1458-1494): tradizione e innovazioni
2015
In seguito alla conquista del regno di Napoli da parte di Alfonso il Magnanimo, la corte, stabilitasi nella capitale, mantenne la struttura ed il funzionamento previsti dalla tradizione aragonese codificata nelle ordinanze di Pietro il Cerimonioso. Sulla base di fonti documentarie recentemente venute alla luce e delle ultime acquisizioni storiografiche, il contributo pone in evidenza come Ferrante, erede del Magnanimo al trono napoletano, sebbene mantenne l’organizzazione palatina ereditata dal padre, per le sue tendenze accentratrici introdusse nell’amministrazione finanziaria centrale talune innovazioni funzionali, al fine di un più ampio controllo delle risorse e delle spese della corte,…
Effect of the Si doping on the properties of AZO/SiC/Si heterojunctions grown by low temperature pulsed laser deposition
2020
Abstract The structural and photoelectrical properties of Al-doped ZnO (AZO)/SiC/p-Si and AZO/SiC/n-Si heterojunctions, fabricated at low temperature by pulsed laser deposition, were investigated by means of a number of techniques. Raman analysis indicates that SiC layers have the cubic 3C-SiC phase, whilst X-ray diffraction measurements show that AZO films exhibit a hexagonal wurtzite structure, highly textured along the c-axis, with average crystallites size of 35.1 nm and lattice parameter c of 0.518 nm. The homogeneous and dense surface morphology observed by scanning electron microscopy was confirmed by atomic force microscopy images. Moreover, UV–Vis-NIR spectra indicated a high trans…