Executive summary in inglese The application of the Hybrid Electric Drives (HED) to the ships has, recently, gained increasing attention. US Marine Corps started several research project to verify the advantages entailed by such application. Anyway, it is clear that the marine propulsion is quite different from the terrestrial application, therefore it is a rather new research field, in which not all the techniques already developed for the Electric Car application can be transposed. Of course, the reduction of the polluting emissions is a convenience even for the marine propulsion: in fact, scientific and/or touristic ships may cross areas in which environment protection laws forbid transit to avoid pollution. Using proper PWM techniques, to control the PWM supply inverter, reduction of mechanical vibrations and, consequently, of the acoustic emissions can be achieved: this can lead to interesting application both in touristic ships, where the increased comfort from a almost-silent motor can be appreciated, and in military ships, where the mechanical vibrations, amplified by the hull, produce an acoustic signature that prevent stealth-mode operations. HED is inherently modular, then it permits to optimize the space on the ship: propellers can be even mounted off-board, in hermetic bulbs, since electrical wiring can be easily placed along the hull. Also, if the ship needs to be updated for any reason, the HED can be easily modified according to the new requirements. On the contrary, regenerative braking in marine propulsion is quite difficult to apply; the problem is the conversion of the ship cinetic energy in mechanical energy applied to the electric machine. In fact, the wing profile for the propeller and the turbine, in other words for the motor and generator behaviour, is different. Anyway it is possible, and experimental cases prove it, to obtain good performances in both motor and generator behaviour, if the wing profile is suitably chosen. The HED has, however, an increased installation cost, since at least one additional electric machine is needed in respect to the tradional Internal Combustion Engine (ICE), and an increase of operating cost, given by the energy conversion from fossil fuel to electric energy. For these reasons, the HED can be profitably applied to the ships whose load profiles offer save margins, in respect to the ICE. HED can be therefore applied to ships that need big propulsion power for limited time or low propulsion power for longer period. Experimental results will be shown to confirm the real save margin offered by the HED.
Executive summary in italiano Recentemente, l'applicazione dei motori ibridi alla propulsione marina ha ottenuto un grande riscontro presso la comunit`a scientifica. Molte organizzazioni, come ad esempio la marina statunitense, hanno cominciato dei progetti di ricerca per verificare l'effettiva applicabilit`a e i vantaggi conseguenti. Date le caratteristiche peculiari dei motori ibridi, appare subito evidente che la loro applicazione alla propulsione marina non `e una mera trasposizione delle tecniche gi`a esistenti per la trazione elettrica. Le imbarcazioni hanno infatti esigenze diverse e pongono quindi differenti problematiche, sebbene alcune similarit`a possano essere individuate. Innanzitutto, la riduzione delle emissioni inquinanti `e un vantaggio anche per la propulsione marina: esistono infatti applicazioni turistiche e scientifiche per cui il transito in zone sottoposte a tutela ambientale `e obbligato, e pertanto disporre di un'imbarcazione ecologicamente compatibile `e indispensabile. La riduzione delle emissioni acustiche, e delle vibrazioni meccaniche, ottenute a mezzo di particolari tenciche di alimentazione dell'azionamento elettrico tramite inverter PWM, pone degli interessanti sviluppi in ambito militare, consentendo le operazioni delle navi nel cosiddetto "stealth-mode", ossia impedendone la rilevazione. La natura modulare del motore ibrido, anche detto Hybrid Electric Drive (HED), permette un migliore sfruttamento degli spazi di bordo, solitamente limitati, consentendo anche una maggiore facilit`a di aggiornamento dell'imbarcazione, per far fronte a mutate esigenze. Di pi`u difficile applicazione risulta invece la rigenerazione dell'energia meccanica in energia elettrica, considerato che le eliche normalmente destinate alla propulsione non offrono buone prestazioni nel funzionamento da turbina. `E tuttavia possibile, e le applicazioni sperimentali mostrate lo dimostrano, ricorrendo a particolari configurazioni di propulsione ovviare a questo inconveniente. La propulsione marina ibrida rimane comunque limitata a certi ambiti, considerato che l'HED comporta un incremento delle spese di installazione e di esercizio che deve essere compensato da un risparmio di combustibile rispetto all'utilizzo del solo motore a combustione interna (ICE). L'HED permette d'altronde di ottimizzare il dimensionamento di ogni sua parte, data la sua natura modulare, pertanto `e possibile ottenere cospicui risparmi se i profili di utilizzo dell'imbarcazione lo consentono: potenze molto elevate per periodi di tempo brevi o, al contrario, potenze basse per periodi di tempo molto lunghi.
La propulsione marina ibrida: stato dell'arte e prospettive
Angelo Accetta;Marcello Pucci;Giuseppe Scordato;Gianpaolo Vitale
2013
Abstract
Executive summary in inglese The application of the Hybrid Electric Drives (HED) to the ships has, recently, gained increasing attention. US Marine Corps started several research project to verify the advantages entailed by such application. Anyway, it is clear that the marine propulsion is quite different from the terrestrial application, therefore it is a rather new research field, in which not all the techniques already developed for the Electric Car application can be transposed. Of course, the reduction of the polluting emissions is a convenience even for the marine propulsion: in fact, scientific and/or touristic ships may cross areas in which environment protection laws forbid transit to avoid pollution. Using proper PWM techniques, to control the PWM supply inverter, reduction of mechanical vibrations and, consequently, of the acoustic emissions can be achieved: this can lead to interesting application both in touristic ships, where the increased comfort from a almost-silent motor can be appreciated, and in military ships, where the mechanical vibrations, amplified by the hull, produce an acoustic signature that prevent stealth-mode operations. HED is inherently modular, then it permits to optimize the space on the ship: propellers can be even mounted off-board, in hermetic bulbs, since electrical wiring can be easily placed along the hull. Also, if the ship needs to be updated for any reason, the HED can be easily modified according to the new requirements. On the contrary, regenerative braking in marine propulsion is quite difficult to apply; the problem is the conversion of the ship cinetic energy in mechanical energy applied to the electric machine. In fact, the wing profile for the propeller and the turbine, in other words for the motor and generator behaviour, is different. Anyway it is possible, and experimental cases prove it, to obtain good performances in both motor and generator behaviour, if the wing profile is suitably chosen. The HED has, however, an increased installation cost, since at least one additional electric machine is needed in respect to the tradional Internal Combustion Engine (ICE), and an increase of operating cost, given by the energy conversion from fossil fuel to electric energy. For these reasons, the HED can be profitably applied to the ships whose load profiles offer save margins, in respect to the ICE. HED can be therefore applied to ships that need big propulsion power for limited time or low propulsion power for longer period. Experimental results will be shown to confirm the real save margin offered by the HED.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
