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The Determination of the Constants of Instrument Transformers

Description: Report issued by the Bureau of Standards over studies on instrument transformers. As stated in the first paragraph, "the principle of the method here described is the same for both current and potential transformers, being an application of the potentiometer method" (p. 281). The methods and equipment studied are presented and discussed.
Date: 1911
Creator: Agnew, P. G. & Fitch, T. T.
Partner: UNT Libraries Government Documents Department

Transformer Efficiency Assessment - Okinawa, Japan

Description: The US Army Engineering & Support Center, Huntsville (USAESCH), and the US Marine Corps Base (MCB), Okinawa, Japan retained Idaho National Laboratory (INL) to conduct a Transformer Efficiency Assessment of “key” transformers located at multiple military bases in Okinawa, Japan. The purpose of this assessment is to support the Marine Corps Base, Okinawa in evaluating medium voltage distribution transformers for potential efficiency upgrades. The original scope of work included the MCB providing actual transformer nameplate data, manufacturer’s factory test sheets, electrical system data (kWh), demand data (kWd), power factor data, and electricity cost data. Unfortunately, the MCB’s actual data is not available and therefore making it necessary to de-scope the original assessment. Note: Any similar nameplate data, photos of similar transformer nameplates, and basic electrical details from one-line drawings (provided by MCB) are not a replacement for actual load loss test data. It is recommended that load measurements are performed on the high and low sides of transformers to better quantify actual load losses, demand data, and power factor data. We also recommend that actual data, when available, be inserted by MCB Okinawa where assumptions have been made and then the LCC analysis updated. This report covers a generalized assessment of modern U.S. transformers in a three level efficiency category, Low-Level efficiency, Medium-Level efficiency, and High-Level efficiency.
Date: May 1, 2012
Creator: Baldwin, Thomas L.; Turk, Robert J.; Myers, Kurt S.; Gentle, Jake P. & Bush, Jason W.
Partner: UNT Libraries Government Documents Department

Transformer Efficiency Assessment - Okinawa, Japan

Description: The US Army Engineering & Support Center, Huntsville (USAESCH), and the US Marine Corps Base (MCB), Okinawa, Japan retained Idaho National Laboratory (INL) to conduct a Transformer Efficiency Assessment of “key” transformers located at multiple military bases in Okinawa, Japan. The purpose of this assessment is to support the Marine Corps Base, Okinawa in evaluating medium voltage distribution transformers for potential efficiency upgrades. The original scope of work included the MCB providing actual transformer nameplate data, manufacturer’s factory test sheets, electrical system data (kWh), demand data (kWd), power factor data, and electricity cost data. Unfortunately, the MCB’s actual data is not available and therefore making it necessary to de-scope the original assessment. Note: Any similar nameplate data, photos of similar transformer nameplates, and basic electrical details from one-line drawings (provided by MCB) are not a replacement for actual load loss test data. It is recommended that load measurements are performed on the high and low sides of transformers to better quantify actual load losses, demand data, and power factor data. We also recommend that actual data, when available, be inserted by MCB Okinawa where assumptions have been made and then the LCC analysis updated. This report covers a generalized assessment of modern U.S. transformers in a three level efficiency category, Low-Level efficiency, Medium-Level efficiency, and High-Level efficiency.
Date: August 1, 2012
Creator: Baldwin, Thomas L.; Turk, Robert J.; Myers, Kurt S.; Gentle, Jake P. & Bush, Jason W.
Partner: UNT Libraries Government Documents Department

Transformer Efficiency Assessment - Okinawa, Japan

Description: The US Army Engineering & Support Center, Huntsville (USAESCH), and the US Marine Corps Base (MCB), Okinawa, Japan retained Idaho National Laboratory (INL) to conduct a Transformer Efficiency Assessment of “key” transformers located at multiple military bases in Okinawa, Japan. The purpose of this assessment is to support the Marine Corps Base, Okinawa in evaluating medium voltage distribution transformers for potential efficiency upgrades. The original scope of work included the MCB providing actual transformer nameplate data, manufacturer’s factory test sheets, electrical system data (kWh), demand data (kWd), power factor data, and electricity cost data. Unfortunately, the MCB’s actual data is not available and therefore making it necessary to de-scope the original assessment. Note: Any similar nameplate data, photos of similar transformer nameplates, and basic electrical details from one-line drawings (provided by MCB) are not a replacement for actual load loss test data. It is recommended that load measurements are performed on the high and low sides of transformers to better quantify actual load losses, demand data, and power factor data. We also recommend that actual data, when available, be inserted by MCB Okinawa where assumptions have been made and then the LCC analysis updated. This report covers a generalized assessment of modern U.S. transformers in a three level efficiency category, Low-Level efficiency, Medium-Level efficiency, and High-Level efficiency.
Date: May 1, 2012
Creator: Baldwin, Thomas L.; Turk, Robert J.; Myers, Kurt S.; Gentle, Jake P. & Bush, Jason W.
Partner: UNT Libraries Government Documents Department

A least squares method for CVT calibration in a RLC capacitor discharge circuit.

Description: In many applications, the ability to monitor the output of a capacitive discharge circuit is imperative to ensuring the reliability and accuracy of the unit. This monitoring is commonly accomplished with the use of a Current Viewing Transformer (CVT). In order to calibrate the CVT, the circuit is assembled with a Current Viewing Transformer (CVR) in addition to the CVT and the peak outputs compared. However, difficulties encountered with the use of CVRs make it desirable to eliminate the use of the CVR from the calibration process. This report describes a method for determining the calibration factor between the current throughput and the CVT voltage output in a capacitive discharge unit from the CVT ringdown data and values of initial voltage and capacitance of the circuit. Previous linear RLC fitting work for determining R, L, and C is adapted to return values of R, L, and the calibration factor, k. Separate solutions for underdamped and overdamped cases are presented and implemented on real circuit data using MathCad software with positive results. This technique may also offer a unique approach to self calibration of current measuring devices.
Date: November 1, 2003
Creator: Yao, Stephen E.; Dickey, Fred McCartney & Pecak, Sara North
Partner: UNT Libraries Government Documents Department

Ramp-up of CHI Initiated Plasmas on NSTX

Description: Experiments on the National Spherical Torus (NSTX) have now demonstrated flux savings using transient coaxial helicity injection (CHI). In these discharges, the discharges initiated by CHI are ramped up with an inductive transformer and exhibit higher plasma current than discharges without the benefit of CHI initiation.
Date: October 29, 2009
Creator: Mueller, D; Bell, R E; LeBlanc, B; Roquemore, A L; Raman, R; Jarboe, T R et al.
Partner: UNT Libraries Government Documents Department

A High-Voltage Pulse Transformer for Explosive Pulsed-Power Devices

Description: It is often necessary to use a high-voltage pulse transformer for impedance matching an explosive generator to a higher impedance load. Also, a particular application may require high-voltage rather than the high current which flux compressor generators (FCGs) normally deliver when driving suitable low impedance loads. We have designed and built transformers for use with FCGs. They are air-core transformers with measured coupling coefficients in the range of 0.88 to 0.94. The turns ratio for these transformers vary from 10 to 40. We have used these transformers in FCG shots and have measured 250 kV and 250 kA on the secondary, simultaneously and without breakdown. So far the FCG and not the transformer have limited the voltage. Experiments to determine a voltage limit are ongoing. Our design and results are presented.
Date: October 1, 1998
Creator: Fortgang, C.; Erickson, G.A. & Goettee, J.
Partner: UNT Libraries Government Documents Department

Economic analysis of efficient distribution transformer trends

Description: This report outlines an approach that will account for uncertainty in the development of evaluation factors used to identify transformer designs with the lowest total owning cost (TOC). The TOC methodology is described and the most highly variable parameters are discussed. The model is developed to account for uncertainties as well as statistical distributions for the important parameters. Sample calculations are presented. The TOC methodology is applied to data provided by two utilities in order to test its validity.
Date: March 1, 1998
Creator: Downing, D. J.; McConnell, B. W.; Barnes, P. R.; Hadley, S. W. & Van Dyke, J. W.
Partner: UNT Libraries Government Documents Department

Method and Appartus for Calibrating a Linear Variable Differential Transformer

Description: A calibration apparatus for calibrating a linear variable differential transformer (LVDT) having an armature positioned in au LVDT armature orifice, and the armature able to move along an axis of movement. The calibration apparatus includes a heating mechanism with an internal chamber, a temperature measuring mechanism for measuring the temperature of the LVDT, a fixture mechanism with an internal chamber for at least partially accepting the LVDT and for securing the LVDT within the heating mechanism internal chamber, a moving mechanism for moving the armature, a position measurement mechanism for measuring the position of the armature, and an output voltage measurement mechanism. A method for calibrating an LVDT, including the steps of powering the LVDT; heating the LVDT to a desired temperature; measuring the position of the armature with respect to the armature orifice; and measuring the output voltage of the LVDT.
Date: January 18, 2005
Creator: Pokrywka, Robert J.
Partner: UNT Libraries Government Documents Department

Experimental Measurements of the Demo Enclosure

Description: The ''demo enclosure'' is a small box constructed at ARL/PSU to simulate the basic characteristics of an equipment enclosure, but without the complexity of an actual enclosure. In the general case, an equipment enclosure can house a variety of electrical equipment, including transformers, card racks, etc., usually mounted on shelves. They are primarily interested in investigating the best way to mount the shelves in the enclosure to mitigate sound radiation due to the excitation from the electrical equipment. A secondary goal is to assess methods for modeling the structural properties of interconnected shelves and cabinets along with the electrical equipment. In this report, they will concentrate on the extensive experimental measurements made during the investigation.
Date: February 5, 2004
Creator: Fahnline, JB; Holmberg, W; Seeger, G; Campbell, RL & Hambric, SA
Partner: UNT Libraries Government Documents Department

Helical Pulse Line Structures for Ion Acceleration

Description: The basic concept of the ''Pulse Line Ion Accelerator'' is presented, where pulse power sources create a ramped traveling wave voltage pulse on a helical pulse line. Ions can surf on this traveling wave and achieve energy gains much larger than the peak applied voltage. Tapered and untapered lines are compared, and a transformer coupling technique for launching the wave is described.
Date: May 1, 2005
Creator: Briggs, R.J.; Reginato, L.L. & Waldron, W.L.
Partner: UNT Libraries Government Documents Department

Online Monitoring Technical Basis and Analysis Framework for Large Power Transformers; Interim Report for FY 2012

Description: The Light Water Reactor Sustainability program at Idaho National Laboratory (INL) is actively conducting research to develop and demonstrate online monitoring (OLM) capabilities for active components in existing Nuclear Power Plants. A pilot project is currently underway to apply OLM to Generator Step-Up Transformers (GSUs) and Emergency Diesel Generators (EDGs). INL and the Electric Power Research Institute (EPRI) are working jointly to implement the pilot project. The EPRI Fleet-Wide Prognostic and Health Management (FW-PHM) Software Suite will be used to implement monitoring in conjunction with utility partners: the Shearon Harris Nuclear Generating Station (owned by Duke Energy for GSUs, and Braidwood Generating Station (owned by Exelon Corporation) for EDGs. This report presents monitoring techniques, fault signatures, and diagnostic and prognostic models for GSUs. GSUs are main transformers that are directly connected to generators, stepping up the voltage from the generator output voltage to the highest transmission voltages for supplying electricity to the transmission grid. Technical experts from Shearon Harris are assisting INL and EPRI in identifying critical faults and defining fault signatures associated with each fault. The resulting diagnostic models will be implemented in the FW-PHM Software Suite and tested using data from Shearon-Harris. Parallel research on EDGs is being conducted, and will be reported in an interim report during the first quarter of fiscal year 2013.
Date: September 1, 2012
Creator: Lybeck, Nancy J.; Agarwal, Vivek; Pham, Binh T.; Medema, Heather D. & Fitzgerald, Kirk
Partner: UNT Libraries Government Documents Department

High Voltage Pulsar For 184-inch Cyclotron Electric Deflector

Description: This paper describes a high voltage pulse generator developed to deflect the beam of the 184-inch cyclotron at Berkeley, California. The apparatus develops a deflecting potential of 200 kilovolts that rises from 10% to 90% of peak value in 0.1 microseconds. The unit employs two similar 100 kilovolt water cooled pulse transformers connected symmetrically about ground to the electric deflector bars. Water-cooled General Electric pulse capacitors are discharged through the two turn primary windings of the pulse transformers by triggering a battery of 16 paralleled Kuthe 5022 hydrogen thyratrons. Output voltages are developed across the 17 turn secondary winding of the pulse transformer. The transformer is mounted in an oil filled lucite case that provides both insulation and compact design.
Date: April 24, 1948
Creator: Kerns, Q.A.; Baker, W.R.; Edwards, R.F. & Farly, G.M.
Partner: UNT Libraries Government Documents Department

Commissioning of the new AGS MMPS transformers

Description: The Brookhaven AGS Main Magnet Power Supply (MMPS) is a thyristor control supply rated at 5500 Amps. +/-9000 Volts. The peak magnet power is 50 MWatts. The power supply is fed from a motor/generator manufactured by Siemens. During rectify and invert operation the P Bank power supplies are used. During the flattops the F Bank power supplies are used. The P Bank power supplies are fed from two 23 MVA transformers and the F Bank power supplies are fed from two 5.3 MYA transformers. The fundamental frequency of the F Bank power supplies is 1440 Hz, however the fundamental frequency of the P banks was 720 Hz. It was very important to reduce the ripple during rectify to improve polarized proton operations. For this reason and also because the original transformers were 45 years old we replaced these transformers with new ones and we made the fundamental frequency of both P and F banks 1440 Hz. This paper will highlight the major hurdles that were involved during the installation of the new transformers. It will present waveforms while running at different power levels up to 6MW full load. It will show the transition from the F-Bank power supplies to the P-Banks and also show the improvements in ripple made on the P-Bank power supplies.
Date: May 4, 2009
Creator: Bajon,E.; Badea, V. S.; Bannon, M.; Bonati, R.; Marneris, I. M.; Porqueddu, r. et al.
Partner: UNT Libraries Government Documents Department

Design of Tunable/Reconfigurable and Compact Microwave Devices

Description: With the rapid development of the modern technology, radio frequency and microwave systems are playing more and more important roles. Since the time the first microwave device was invented, they have been leading not only the military but also our daily life to a new era. In order to make the devices have more practical applications, more and more strict requirements have been imposed. For example, good adaptability, reduced cost and shrank size are highly required. In this thesis, three devices are designed based on this requirement. At first, a symmetric four-port microwave varactor based 90-degree directional coupler with tunable coupling ratios and reconfigurable responses is presented. The proposed coupler is designed based on the modified structure of a crossover, where varactors are loaded. Then, a novel reconfigurable 3-dB directional coupler is presented. Varactors and inductors are loaded to the device to realize the reconfigurable performance. By adjusting the voltage applied to the varactors, the proposed coupler can be reconfigured from a branch-line coupler (90-degree coupler) to a rat-race coupler (180 degree coupler) and vice versa. At last, two types (Type-I and Type-II) of microwave baluns with generalized structures are presented. Different from the conventional transmission-line-based baluns where λ/2 transmission lines or λ/4 coupled lines are used, the proposed baluns are constructed by transmission lines with arbitrary electrical lengths.
Date: May 2014
Creator: Zhou, Mi
Partner: UNT Libraries

Acceptance test procedure for removal of CS1K circuit switcher block and trip schemes

Description: This supporting document provides a detailed process to test the functions of the circuit switcher, protective relays, alarms, SCADA and 125VDC control logic of 115kV and 13.8kV systems at B3S4 substation following the removal of trip and blocking schemes to Transformer No.1 Circuit Switcher B594.
Date: August 25, 1999
Creator: HACHE, J.M.
Partner: UNT Libraries Government Documents Department

Development of the pulse transformer for NLC klystron pulse modulator

Description: We have studied a conventional pulse transformer for the NLC klystron pulse modulator. The transformer has been analyzed using a simplified lumped circuit model. It is found that a fast rise time requires low leakage inductance and low distributed capacitance and can be realized by reducing the number of secondary turns, but it produces larger pulse droop and core size. After making a tradeoff among these parameters carefully, a conventional pulse transformer with a rise time of 250ns and pulse droop of 3.6% has been designed and built. The transmission characteristics and pulse time-response were measured. The data were compared with the model. The agreement with the model was good when the measured values were used in the model simulation. The results of the high voltage tests are also presented.
Date: May 1, 1997
Creator: Akemoto, M.; Gold, S.; Koontz, R. & Krasnykh, A.
Partner: UNT Libraries Government Documents Department