Optimizing three-phase planar transformer construction

A three-phase transformer with flat conductor layers is proposed in this article. This arrangement is used for high current density transformers. Cost effectiveness in planar magnetic are related with the optimization in the number of layers in each winding. This fact takes more relevance for the medium and high power three-phase transformers where the number of parallels to achieve the required DCR is increased. The proposed method allows the use of off-the-shell core shapes that are used for single phase transformers. Cost impact is significant and design implications become more flexible. The proposed solution has been validated and compared using the conventional and the proposed methodologies to design a high power (20 kW) transformer.

An alternative for reducing the layers in the construction of three-phase planar transformers

A modified winding layout for three-phase transformers with PCB windings is proposed in this paper. This modified layout can be used in high current transformers with many PCB layers to simplify the fabrication process. One of the key factors that might increase the cost and complexity in the construction of planar transformers is the number of layers of each PCB winding. This issue becomes even more important in medium-high power three-phase transformers, where the number of PCB layers is higher. In addition to that, the proposed method allows the use of commercial core shapes that are commonly used to design single-phase transformers. This fact makes possible the reduction of cost and flexibility of the design solutions. The proposed solution has been validated and compared using the conventional and the proposed methodologies to design a high power (20 kW) transformer.

Adaptive Control for ZVS Three Phase Full Active Bridge Converter with ARCN

This paper presents an adaptive control for the auxiliary circuit, called ARCN (Auxiliary Resonant Commutating Network), used to achieve ZVS in full active bridge converters under a wide load range. Depending on the load conditions, the proposed control adapts the timing of the ARCN to minimize the losses. The principle of operation and implementation considerations are presented for a three phase full active bridge converter, proposing different methods to implement the control according to the specifications. The experimental results shown verify the proposed methodology.

3-Phase Rectifier System with very demanding dynamic load: Architecture analysis and control strategy

A distributed power architecture for aerospace application with very restrictive specifications is analyzed. Parameters as volume, weight and losses are analyzed for the considered power architectures. In order to protect the 3 phase generator against high load steps, an intermediate bus (based in a high capacitance) to provide energy to the loads during the high load steps is included. Prototypes of the selected architecture for the rectifier and EMI filter are built and the energy control is validated.

A report on the three-dee, three-phase 20-inch cyclotron /

Unclassified Physics Distribution.

Three phase system for statewide evaluation of occupational education programs : team leader handbook.

Cover title.

Organizational maintenance repair parts and special tools list : air conditioning units, electric motor driven, 9,000 Btu/hr, vertical compact, 115 volt, single phase, 50/60 cycle (Therm-Air Manufacturing Co. model CV-9-1-15-60) FSN 4120-935-1609; 9,000 Btu/hr, vertical compact, 230 volt, three phase, 50/60 cycle ....

"February 1970."

Operator, organizational, direct support, general support and depot maintenance manual : air conditioning units, electric motor driven, 6,000 BTU/hr, vertical compact, 115 volt, single phase, 50/60 cycle (Thermo-Air model CV-6-1-15-60), FSN 4120-935-1608, 6,000 BTU/hr vertical compact, 208 volt, three phase, 400 cycle (Thermo-Air model CV-6-3-08-400), FSN 4120-935-1607.

Includes index.

Operator, organizational, direct support, general support, and depot maintenance manual : air conditioner, vertical, compact, 208 volts, A.C., 400 hertz, three phase, 18,000 BTU/hr cooling, 12,000 BTU/hr heating, (Keco model F18T4-2) FSN 4120-168-1775.

Includes index.

Operator's, organizational, direct support, and general support maintenance manual : air conditioner, horizontal, compact, 9,000 BTU/hr, 208 volt, three phase 50/60 hertz, model ECU-9HC326, NSN 4120-01-193-4998.

"27 March 1987."

Operator, organizational, direct support and general support maintenance manual : air conditioner, vertical compact, 6,000 BTU, 115 volts, single phase, 60 hertz (WEDJ model VM 6000-115) NSN 4120-00-935-1608 : air conditioner, vertical compact, 6,000 BTU, 208 volts, three phase, 400 hertz (WEDJ model VM 6000-208) NSN 4120-00-935-1607.

Includes index.

Organizational, direct support, and general support maintenance repair parts and special tools list (including depot maintenance repair parts and special tools) for air conditioner, vertical compact, 6,000 BTU, 115 volt, single phase, 50/60 Hz, Wedj model VM 6000-15, NSN 4120-00-935-1608 ... 208 volts, three phase, 400 Hz, Wedj model VM 6000-400, NSN 4120-00-935-1607.

Includes index.

Operator, organizational, direct support, and general support maintenance manual : air conditioner, vertical, compact, 18,000 Btu hr, 208 volts, three phase, 400 hertz (WEDJ model VM 18000-400), NSN 4120-00-152-1150.

"28 July 1979."

Hydrodynamics and mass transfer coefficient in three-phase air-lift reactors containing activated sludge

This study was to investigate the impacts of operating conditions and liquid properties on the hydrodynamics and volumetric mass transfer coefficient in activated sludge air-lift reactors. Experiments were conducted in internal and external air-lift reactors. The activated sludge liquid displayed a non-Newtonian rheological behavior. With an increase in the superficial gas velocity, the liquid circulation velocity, gas holdup and mass transfer coefficient increased, and the gas residence time decreased. The liquid circulation velocity, gas holdup and the mass transfer coefficient decreased as the sludge loading increased. The flow regime in the activated sludge air-lift reactors had significant effect on the liquid circulation velocity and the gas holdup, but appeared to have little impact on the mass transfer coefficient. The experimental results in this study were best described by the empirical models, in which the reactor geometry, superficial gas velocity and/or power consumption unit, and solid and fluid properties were employed. (c) 2006 Elsevier B.V. All rights reserved.