1,721,091 research outputs found
Prove di caratterizzazione di un simulatore FCS - "Sperimentazione e caratterizzazione di un Fuel Cell Powertrain di tipologia innovativa"
No full textLa ricerca si è svolta nell'ambito del Contratto ENEA dal titolo:"Sperimentazione e caratterizzazione di un Fuel Cell Powertrain di tipologia innovativa" .Il simulatore di fuel-cell è costituito da un ponte a tiristori con in parallelo sull’uscita un opportuno banco di condensatori e batterie.Il sistema fuel-cell è stato caratterizzato alimentando un banco di resistenze di cui è possibile variare il valore ohmico nell’intervallo inf-2.85. Il banco di resistenze è alimentato, tramite il MIPEC, alla tensione di circa 215V dal simulatore di fuel-cell; in corrispondenza ai diversi valori del carico la corrente della fuel-cell varia nell’intervallo 0-110A. In corrispondenza ai diversi valori di carico sono state visualizzate e misurate la tensione e corrente del sistema fuel-cell e la tensione e corrente del carico. Lo strumento utilizzato è l’analizzatore di segnale DL708 Yokogawa; le grandezze in corrente sono state misurate tramite sonde LEM HA400SU
Integral-resonant control for stand-alone voltage source inverters
No full textThis study deals with a newly-conceived voltage control method for three-phase four-leg voltage source inverters
(VSIs) which are being required in autonomous power generating units devoted to supply both three-phase and single-phase electrical loads in four-wire electric power distribution systems. To deal with VSI operating conditions providing three-phase voltage supply of both unbalanced loads and non-linear loads, an integral + resonant (I + R) voltage control structure is discussed and experimentally verified by means of a 25 kVA rated power converter prototype. It is shown that the proposed voltage control allows simplifying the overall control configuration, achieving zero-overhead power factor regulation and fast compensation of load unbalances. Further to that, a complete current limiting strategy is described and tested under different load conditions
Comparison of Modulation Techniques for Active Split DC-Bus Three-Phase Four-Leg Inverters
No full text
An HVCB Electronic Drive for Modern Electrical Substation in Distribution Power Systems
No full textThe growing need for automation leads to the development of new electronic devices in greater and different
fields of applications. One interest is new automation devices for high-voltage distribution substations. High-voltage circuit breakers (HVCBs) use a mechanical-based operation mechanism to open and close maneuvers. Conventional breaker drives are old and complicated to adapt to new electronics automated devices, such as remote monitoring supervision systems, measurements-acquisition systems, and protection systems. To obtain more flexibility and higher reliability, a new electronic operation mechanism, which can interface with modern substations and automation
systems, is presented here and investigated. An evolution of the first electronic drive presented in the past years is described here through simulation and field test. Successful results gathered after IEC62271-100-type tests confirm the reliability and stability of this kind of new operating mechanism on full-scaled HVCBs and support its use in high-performance demand breakers, in terms of speed and energy request
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