9 results on '"Bolognesi, Paolo"'
Search Results
2. A Consequent-Pole Hybrid Exciter for Synchronous Generators.
- Author
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Nuzzo, Stefano, Bolognesi, Paolo, Decuzzi, Giovanni, Giangrande, Paolo, and Galea, Michael
- Subjects
- *
SYNCHRONOUS generators , *PERMANENT magnets , *HYBRID power systems , *ELECTROMAGNETS , *SYSTEMS design , *SYSTEM analysis - Abstract
In low-to-medium power generating sets, a self-powered brushless excitation system is typically employed. This solution is cost-effective, simple and compact, but it suffers from an unreliable voltage build-up at start-up, a slow dynamic response and a relatively low efficiency for the exciter. The push towards more effective, reliable and efficient products has recently led to consider excitation systems equipped with permanent magnet exciters and controlled rotating converters, but their diffusion is limited by their higher complexity and cost. This article investigates the utilization of a hybrid excitation for the exciter, aiming to join the benefits of field windings and permanent magnets. As a case study, this concept is applied to a commercial mid-size generating set adopting an industrial perspective, aiming to maximize the benefits while minimizing the required modifications in the system design. After a preliminary analysis, a consequent-pole layout with surface-mounted bonded magnets is then selected as the most effective solution. Theoretical considerations, numerical analysis and experimental validation are reported to show that the hybrid excitation concept can actually lead to a significant reduction of the exciter field losses as well as to other appreciable side benefits with a very limited impact on the present design of the generating set. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
3. An Analytical-Numerical Approach to Model and Analyse Squirrel Cage Induction Motors.
- Author
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Marfoli, Alessandro, Papini, Luca, Bolognesi, Paolo, and Gerada, Chris
- Subjects
SQUIRREL cage motors ,ELECTROMAGNETIC devices ,FINITE element method ,COMPUTATIONAL electromagnetics - Abstract
Nowadays, finite element analysis represents the most accurate tool to analyse electrical machines. However, the time domain resolution of electromagnetic problem, in some cases, requires long simulation time due to the induced nature of the currents. The computational burden increases when the machine features a skewed layout on the stator or rotor structures, since this requires 2D multi-slices approximated analysis or even a full 3D model. In this paper, a general analytical method to model electromagnetic devices is applied to a squirrel cage induction motor featuring a skewed rotor structure. The modelling approach is wisely implemented and adapted to pursue a fair balance between accuracy of the analysis and computational burden, taking advantage of all the symmetries existing in the rotor cage of the machine, aiming to minimize the model complexity. A comparative analysis in term of the inductances between analytical and finite element is proposed. The results provided by the model developed are compared with respect to the corresponding values provided by both finite element and experimental test performed on the reference machine. Such comparisons show that the proposed model is actually able to achieve a pretty good balance between accuracy and computational efficiency. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
4. Simplified Damper Cage Circuital Model and Fast Analytical–Numerical Approach for the Analysis of Synchronous Generators.
- Author
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Nuzzo, Stefano, Bolognesi, Paolo, Gerada, Chris, and Galea, Michael
- Subjects
- *
SYNCHRONOUS generators , *SHOCK absorbers - Abstract
The long and enduring history of utilization of the wound-field synchronous generator in a large number of applications makes it one of the most known and consolidated electrical machine technologies. Thus, its design, modeling, and analysis processes have been widely exploited and implemented through various and different methods, including the equivalent circuit approach. When a damper cage is embedded within the rotor of the synchronous generator, its theoretical analysis becomes quite complicated. Thus, today numerical tools are being used. In this paper, an alternative way of modeling symmetric damper cages of salient-pole synchronous generators is presented. The proposed approach is embedded in the circuital model of the generator. A hybrid analytical–numerical model is implemented, permitting to accurately predict the voltage waveforms of the generator with excellent accuracy, however, at a lower cost of computational resources than the pure numerical method. A case study of an off-the-shelf 400 kVA machine is considered to develop and validate the proposed technique. The results are compared with the corresponding finite-element and experimental evaluations for validation purposes. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
5. Design of electromagnetic components for EV battery chargers.
- Author
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Stratta, Andrea, Bolognesi, Paolo, Biagini, Veronica, Biskoping, Matthias, and Tombelli, Fabio
- Subjects
CONVERTERS (Electronics) -- Design & construction ,ELECTROMAGNETISM ,ELECTRIC vehicle batteries ,BATTERY chargers ,ELECTRIC transformers ,ELECTRIC inductors - Abstract
This study focuses on the appropriate design of the inductive elements of the LLC converter based on a typical industrial approach, i.e. assuming to use standard parts available on the market from qualified manufacturers. At first, a methodology to select the passive components is presented, highlighting the difference between the external inductor solution and the magnetically integrated solution. Secondly the step-by-step procedure used for the design of the high frequency transformer is illustrated. The possibility to integrate the resonant inductors into the HF transformer is then analysed, presenting different solutions. Finally a comparison between a classical and an integrated design is then presented referring to a case study; thus permitting to endow the potential benefits of the integrated solution. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
6. A Methodology to Remove Stator Skew in Small–Medium Size Synchronous Generators via Innovative Damper Cage Designs.
- Author
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Nuzzo, Stefano, Galea, Michael, Bolognesi, Paolo, Vakil, Gaurang, Fallows, Daniel, Gerada, Chris, and Brown, Neil
- Subjects
SYNCHRONOUS generators ,STATORS ,HARMONIC distortion (Physics) ,ELECTRIC generators ,ELECTRIC potential - Abstract
This paper proposes and investigates an innovative methodology that can have a significant impact on the market potential of wound field, small–medium size synchronous generators (SGs). The technique proposed here is aimed at removing the need for the traditional stator skewing that is so commonly used in SGs to achieve acceptable values of voltage total harmonic distortion. To do this, a nonstandard damper cage configuration is proposed that comprises modulation of the damper bars’ positioning. An off-the-shelf, 400-kVA generator is used as a benchmark machine. Its rotor is optimized and modified according to the proposed technique. The results of the final machine are then compared to the benchmark machine highlighting the excellent advantages that can be achieved through this technique. A full-scale prototype of the modified generator is then built to experimentally validate the concept. Finally, a detailed analysis on all the performance aspects of the prototype is carried out, to guarantee that the proposed technique has no negative impact whatsoever on the generator's performance. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
7. Olanzapine, but not clozapine, increases glutamate release in the prefrontal cortex of freely moving mice by inhibiting D-aspartate oxidase activity.
- Author
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Sacchi, Silvia, Novellis, Vito De, Paolone, Giovanna, Nuzzo, Tommaso, Iannotta, Monica, Belardo, Carmela, Squillace, Marta, Bolognesi, Paolo, Rosini, Elena, Motta, Zoraide, Frassineti, Martina, Bertolino, Alessandro, Pollegioni, Loredano, Morari, Michele, Maione, Sabatino, Errico, Francesco, and Usiello, Alessandro
- Abstract
D-aspartate levels in the brain are regulated by the catabolic enzyme D-aspartate oxidase (DDO). D-aspartate activates NMDA receptors, and influences brain connectivity and behaviors relevant to schizophrenia in animal models. In addition, recent evidence reported a significant reduction of D-aspartate levels in the post-mortem brain of schizophrenia-affected patients, associated to higher DDO activity. In the present work, microdialysis experiments in freely moving mice revealed that exogenously administered D-aspartate efficiently cross the blood brain barrier and stimulates L-glutamate efflux in the prefrontal cortex (PFC). Consistently, D-aspartate was able to evoke L-glutamate release in a preparation of cortical synaptosomes through presynaptic stimulation of NMDA, mGlu5 and AMPA/kainate receptors. In support of a potential therapeutic relevance of D-aspartate metabolism in schizophrenia, in vitro enzymatic assays revealed that the second-generation antipsychotic olanzapine, differently to clozapine, chlorpromazine, haloperidol, bupropion, fluoxetine and amitriptyline, inhibits the human DDO activity. In line with in vitro evidence, chronic systemic administration of olanzapine induces a significant extracellular release of D-aspartate and L-glutamate in the PFC of freely moving mice, which is suppressed in Ddo knockout animals. These results suggest that the second-generation antipsychotic olanzapine, through the inhibition of DDO activity, increases L-glutamate release in the PFC of treated mice. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
8. Electron pair escape from fullerene cage via collective modes.
- Author
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Schüler, Michael, Pavlyukh, Yaroslav, Bolognesi, Paolo, Avaldi, Lorenzo, and Berakdar, Jamal
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- 2016
- Full Text
- View/download PDF
9. Leucine-rich repeat kinase 2 (LRRK2) inhibitors differentially modulate glutamate release and Serine935 LRRK2 phosphorylation in striatal and cerebrocortical synaptosomes.
- Author
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Mercatelli D, Bolognesi P, Frassineti M, Pisanò CA, Longo F, Shimshek DR, and Morari M
- Subjects
- Animals, Corpus Striatum drug effects, Corpus Striatum metabolism, Dopamine metabolism, Exocytosis, Gene Knock-In Techniques, Glutamic Acid metabolism, Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 antagonists & inhibitors, Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 chemistry, Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 genetics, Male, Mice, Phosphorylation, Serine metabolism, Synaptosomes drug effects, Synaptosomes metabolism, Visual Cortex drug effects, Visual Cortex metabolism, Aminopyridines pharmacology, Benzamides pharmacology, Benzodiazepinones pharmacology, Corpus Striatum cytology, Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 metabolism, Pyrimidines pharmacology, Visual Cortex cytology
- Abstract
Mutations in leucine-rich repeat kinase 2 ( LRRK2 ) gene have been pathogenically linked to Parkinson's disease, and pharmacological inhibition of LRRK2 is being pursued to tackle nigro-striatal dopaminergic neurodegeneration. However, LRRK2 kinase inhibitors may have manifold actions, affecting not only pathological mechanisms in dopaminergic neurons but also physiological functions in nondopaminergic neurons. Therefore, we investigated whether LRRK2 kinase inhibitors differentially modulate dopamine and glutamate release from the mouse striatum and cerebral cortex. Spontaneous and KCl-evoked [
3 H]-dopamine and glutamate release from superfused synaptosomes obtained from wild-type and LRRK2 knock-out, kinase-dead or G2019S knock-in mice was measured. Two structurally unrelated inhibitors, LRRK2-IN-1 and GSK2578215A, were tested. LRRK2, phosphoSerine1292 and phosphoSerine935 LRRK2 levels were measured in all genotypes, and target engagement was evaluated by monitoring phosphoSerine935 LRRK2. LRRK2-IN-1 inhibited striatal glutamate but not dopamine release; GSK2578215A inhibited striatal dopamine and cortical glutamate but enhanced striatal glutamate release. LRRK2-IN-1 reduced striatal and cortical phosphoSerine935 levels whereas GSK2578215A inhibited only the former. Neither LRRK2 inhibitor affected neurotransmitter release in LRRK2 knock-out and kinase-dead mice; however, they facilitated dopamine without affecting striatal glutamate in G2019S knock-in mice. GSK2578215A inhibited cortical glutamate release in G2019S knock-in mice. We conclude that LRRK2-IN-1 and GSK2578215A modulate exocytosis by blocking LRRK2 kinase activity, although their effects vary depending on the nerve terminal examined. The G2019S mutation unravels a dopamine-promoting action of LRRK2 inhibitors while blunting their effects on glutamate release, which highlights their positive potential for the treatment of PD, especially of LRRK2 mutation carriers., Competing Interests: DRS is employed by Novartis Pharma. All other Authors declare no competing interests.- Published
- 2019
- Full Text
- View/download PDF
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