Interleaved multi-cell isolated three-phase PWM rectifier system for aircraft applications

Recently there has been an important increase in electric equipment, as well as, electric power demand in aircrafts applications. This prompts to the necessity of efficient, reliable, and low-weight converters, especially rectifiers from 115VAC to 270VDC because these voltages are used in power distribution. In order to obtain a high efficiency, in aircraft application where the derating in semiconductors is high, normally several semiconductors are used in parallel to decrease the conduction losses. However, this is in conflict with high reliability. To match both goals of high efficiency and reliability, this work proposes an interleaved multi-cell rectifier system, employing several converter cells in parallel instead of parallel-connected semiconductors. In this work a 10kW multi-cell isolated rectifier system has been designed where each cell is composed of a buck type rectifier and a full bridge DC-DC converter. The implemented system exhibits 91% of efficiency, high power density (10kW/10kg), low THD (2.5%), and n−1 fault tolerance which complies, with military aircraft standards.

Bidirectional multiple port dc/dc transformer based on a series resonant converter

In this paper a novel bidirectional multiple port dc/dc transformer topology is presented. The novel concept for dc/dc transformer is based on the Series Resonant Converter (SRC)topology operated at its resonant frequency point. This allows for higher switching frequency to be adopted and enables high efficiency/high power density operation. The feasibility of the proposed concept is verified on a 300W, 700 kHz three port prototype with 390V input voltage and 48V and 12V output voltages. A peak overall efficiency of 93% is measured at full load. A very good load and cross regulation characteristic of the converter is observed in the whole load range, from full load to open circuit. The sensitivity analysis of the resonant capacitance is also performed showing very slight deterioration in the converter performances when a resonant capacitor is changed ±30% of its nominal value.

Ammonia and Greenhouse Gases Emission from Slurry Storage with impermeable Cover and Landspreading of Cattle Slurry

Intensive farm systems handle large volume of livestock wastes, resulting in adverse environmental effects, such as gaseous losses into the atmosphere in form of ammonia (NH3) and greenhouse gases (GHG), i.e. methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O). In this study, the manure management continuum of slurry storage with impermeable cover and following cattle slurry band spreading and incorporation to soil was assessed for NH3 and GHG emissions. The experiment was conducted in an outdoor covered storage (flexible bag system) (study I), which collected the slurry produced in 7 dairy cattle farms (2,000 m3 slurry) during 12 days in the northern Spain.

Recycling grant results : a summary of round 2 grants conducted from June 1988 - August 1989 under the Illinois Solid Waste Management Act.

"September 1989."

Operator's manual : grinding machine, machine tool attachment, internal and external grinding, 5" maximum external diameter wheel, 1/4" minimum internal diameter wheel, 4,600 to 42,400 rpm spindle speed, 1/2 hp, AC/DC, 115 V, 60-C, single phase (Dumore series 5) ...

"October 1967."

Direct support and general support maintenance manual : water purification unit, van type, body mounted, electric motor driven, AC, DC, 115, 208 V, single and 3 phase, 60 hertz, 1/20 to 2 hp, 1500 gph, model EMC-1500S, NSN 4610-01-037-8746, EMC Industries Inc., DAAKO1-76-C-5661.

"1 August 1979."

Operator, organizational, and direct support maintenance manual : generator sets, gasoline engine w/carrying sound housing case, PU-422B/U, 0.4 KW, AC, 115V, 400 Hz and 100V, DC, 29.3V, Admiral model GJ4266 ... PU-532/PPS-4, 0.3 KW, AC, 115V, 400 Hz, 30V, 17 amp, 24V, 2.5 amp, DC, Admiral model G-2633, FSN 6115-889-1212, Henry Spen model 909238-1B, FSN 6115-436-4230.

"March 1973."

Direct support and general support maintenance manual : generator set, 7.5KW, 28V, DC, G.E.D., air cooled, 2 wheel MTD, pneumatic tires, John R. Hollingsworth model JHGV7.5A, FSN 6115-074-6396.

Includes index.

Organizational, direct, and general support maintenance repair parts and special tools list : generator set, 7.5 KW, 28 V, DC, GED, air cooled, 2 wheel mtd, pneumatic tires (John R. Hollingsworth model JHGV7.5A), FSN 6115-074-6396.

Includes index.

Organizational, direct support, and general support maintenance repair parts and special tools lists (including depot maintenance repair parts and special tools) : generator set, gasoline driven, 4.2 KW, 150 AMP, 28V, DC, model DC 4.2-ORD/28 NSN 6115-00-857-1397.

"19 September 1980."

Operator's, organizational, direct support, and general support maintenance manual for generator set, gasoline engine driven, 4.2 KW, 150 AMP, 28V, DC, model DC 4.2 - ORD/28 (6115-00-857-1397).

"20 June 1980."