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Report on the feasibility study for improving electric motor service centers in Ghana

Description: On March 3 and 4, 1998, a visit was made to Oak Ridge National Laboratory (ORNL) by two officials from Ghana: Mr. I.K. Mintah, Acting Executive Director, Technical Wing, Ministry of Mines and Energy (MOME) and Dr. A.K. Ofosu-Ahenkorah, Coordinator, Energy Efficiency and Conservation Program, MOME. As a result of this visit, Dr. John S. Hsu of ORNL was invited by MOME to visit the Republic of Ghana in order to study the feasibility of improving electric motor service centers in Ghana.
Date: December 10, 1999
Creator: Hsu, J.S.; Jallouk, P.A. & Staunton, R.H.
Partner: UNT Libraries Government Documents Department

Status Report on NASA Electronic Power-Factor Control Technology and Development

Description: This report assesses the development of the electronic power-factor control technology as it applies to use with alternating-current induction motors and to identify the potential market of this device and the potential savings this device could produce in the United States energy economy. Included are a status report of the Interagency Agreement between NASA and DOE and the recommendations regarding future efforts of the DOE in the demonstration and commercialization of the power-factor control technology.
Date: 1981
Creator: Koehl, E. R.
Partner: UNT Libraries Government Documents Department

Development of Ultra-Efficient Electric Motors Final Technical Report Covering work from April 2002 through September 2007

Description: High temperature superconducting (HTS) motors offer the potential for dramatic volume and loss reduction compared to conventional, high horspower, industrial motors. This report is the final report on the results of eight research tasks that address some of the issues related to HTS motor development that affect motor efficiency, cost, and reliability.
Date: May 30, 2008
Creator: Schiferl, Rich
Partner: UNT Libraries Government Documents Department

Phase 3 of a Brushless Doubly-Fed Machine System Development Program : Final Technical Report for Period January 1, 1992-June 30, 1993.

Description: Since the inception of the BDFM development program in 1989, the value of BDFM technology has become apparent. The BDFM provides for adjustable speed, synchronous operation while keeping costs associated with the required power conversion equipment lower than in competing technologies. This provides for an advantage in initial as well as maintenance expenses over conventional drive system. Thus, the BDFM enables energy efficient, adjustable speed process control for applications where established drive technology has not been able to deliver satisfactory returns on investment. At the same time, the BDFM challenges conventional drive technologies in established markets by providing for improved performance at lower cost. BDFM converter rating is kept at a minimum, which significantly improves power quality at the utility interface over competing power conversion equipment. In summary, BDFM technology can be expected to provide significant benefits to utilities as well as their customers. This report discusses technical research and development activities related to Phase 3 of the Brushless Doubly-Fed Machine System Development Program, including work made possible by supplemental funds for laboratory improvement and prototype construction. Market research for the BDFM was provided by the College of Business at Oregon State University; market study results will be discussed in a separate report.
Date: December 31, 1993
Creator: Alexander, Gerald C.; Spee, Rene & Wallace, Alan K.
Partner: UNT Libraries Government Documents Department

A Tip Driven Fan Based on SERAPHIM Technology

Description: SERAPHIM technology appears capable of efficiently driving a tip driven fan. If the motor is powered using an inverter and resonant circuit, the size and weight could be considerably below that of a comparable rotary electric motor.
Date: January 1, 2002
Partner: UNT Libraries Government Documents Department

Limitations of the Conventional Phase Advance Method for Constant Power Operation of the Brushless DC Motor

Description: The brushless dc motor (BDCM) has high-power density and efficiency relative to other motor types. These properties make the BDCM well suited for applications in electric vehicles provided a method can be developed for driving the motor over the 4 to 6:1 constant power speed range (CPSR) required by such applications. The present state of the art for constant power operation of the BDCM is conventional phase advance (CPA) [1]. In this paper, we identify key limitations of CPA. It is shown that the CPA has effective control over the developed power but that the current magnitude is relatively insensitive to power output and is inversely proportional to motor inductance. If the motor inductance is low, then the rms current at rated power and high speed may be several times larger than the current rating. The inductance required to maintain rms current within rating is derived analytically and is found to be large relative to that of BDCM designs using high-strength rare earth magnets. Th us, the CPA requires a BDCM with a large equivalent inductance.
Date: October 29, 2001
Creator: Lawler, J.S.
Partner: UNT Libraries Government Documents Department


Description: During this reporting period, significant progress has been made towards the development of the IEMDC System design. Considerable effort was put forth by Curtiss-Wright EMD in the resolution of the technical issue of aerodynamically induced radial forces. This has provided a design basis with which to establish the radial magnetic bearing load capacity and the rotordynamic design. Dresser-Rand has made considerable progress on the flowpath design for the compressor section particularly on the volute and inlet aerodynamic design. All efforts show progression towards the successful integration of a centrifugal compressor and variable speed electric motor ventilated by the process gas. These efforts continue to confirm the feasibility of the IEMDC system design.
Date: June 1, 2003
Creator: Crowley, Michael J.; Bansal, Prem N. & Tessaro, John E.
Partner: UNT Libraries Government Documents Department

Micromachine Wedge Stepping Motor

Description: A wedge stepping motor, which will index a mechanism, has been designed and fabricated in the surface rnicromachine SUMMiT process. This device has demonstrated the ability to index one gear tooth at a time with speeds up to 205 teeth/see. The wedge stepper motor has the following features, whi:h will be useful in a number of applications. o The ability to precisely position mechanical components. . Simple pulse signals can be used for operation. o Only 2 drive signals are requixed for operation. o Torque and precision capabilities increase with device size . The device to be indexed is restrained at all times by the wedge shaped tooth that is used for actuation. This paper will discuss the theory of operation and desi=m of the wedge stepping motor. The fabrication and testing of I he device will also be presented.
Date: November 4, 1998
Creator: Allen, J.J. & Schriner, H.K.
Partner: UNT Libraries Government Documents Department

Energy Efficient Drivepower : Literature Reference List, Volume 2, Design Engineer`s Supplement.

Description: A large number of information sources in the area of the efficient use of drivepower are listed. The main list is for the general user of drivepower systems. The other list is a supplemental reference list for the design engineer.
Date: January 1, 1992
Creator: Ula, Sadrul.; Birnbaum, Larry E. & Jordan, Don
Partner: UNT Libraries Government Documents Department

Ultra-Efficient and Power Dense Electric Motors for U. S. Industry

Description: The primary purpose of this project was to combine the ease-of-installation and ease-of-use attributes of industrial induction motors with the low-loss and small size and weight advantages of PM motors to create an ultra-efficient, high power density industrial motor that can be started across-the-line or operated from a standard, Volts/Hertz drive without the need for a rotor position feedback device. PM motor products that are currently available are largely variable speed motors that require a special adjustable speed drive with rotor position feedback. The reduced size and weight helps to offset the magnet cost in order make these motors commercially viable. The scope of this project covers horsepower ratings from 20 ? 500. Prototypes were built and tested at ratings ranging from 30 to 250 HP. Since fans, pumps and compressors make up a large portion of industrial motor applications, the motor characteristics are tailored to those applications. Also, since there is extensive use of adjustable frequency inverters in these applications, there is the opportunity to design for an optimal pole number and operate at other than 60 Hz frequency when inverters are utilized. Designs with four and eight pole configurations were prototyped as part of this work. Four pole motors are the most commonly used configuration in induction motors today. The results of the prototype design, fabrication, and testing were quite successful. The 50 HP rating met all of the design goals including efficiency and power density. Tested values of motor losses at 50 HP were 30% lower than energy efficient induction motors and the motor weight is 35% lower than the energy efficient induction motor of the same rating. Further, when tested at the 30 HP rating that is normally built in this 286T frame size, the efficiency far exceeds the project design goals with 30 HP efficiency ...
Date: March 12, 2013
Creator: Melfi, Michael J.; Schiferl, Richard F. & Umans, Stephen D.
Partner: UNT Libraries Government Documents Department

Analysis of production line motor failure. CRADA final report for CRADA number Y-1293-0215

Description: The Oak Ridge National Laboratory (ORNL) was approached by a Food Products Manufacturer (FPM) to investigate the rapid failure of motors in a manufacturing facility. It was reported that some motors or their bearings were being replaced after as little as four months of service. The deciding symptom for replacement was always high motor vibration. To protect against unscheduled downtime in the middle of a process run, the FPM`s maintenance team removes a motor from service when its vibration level reaches a conservative threshold of approximately 0.4 inches per second. In their experience, motors left in service after reaching this vibration threshold can fail at any time within the time span of the next process run causing significant losses of raw material and production capacity. A peculiar finding of vibration level trend analysis was that at least one motor exhibited cyclic variations with 24-hour periodicity. The vibration level reached a maximum at about 4:00 a.m., ramped down during the day, and then rose again during the night. Another peculiarity was that most of the vibration energy in the affected motors was at the 120 Hz frequency. Since this is twice the 60 Hz line frequency the FPM suspected the vibration was electrically induced. The electric loads at the FPMs plant remain constant during the five days of a continuous production run. Thus, the periodicity of the vibration observed, with its daily peaking at about four am, suggested the possibility of being driven by changes in the electrical power grid external to the plant.
Date: February 10, 1995
Creator: Kueck, J. & Talbott, C.
Partner: UNT Libraries Government Documents Department

Distributed monitoring system for electric-motor-driven compressors

Description: Personnel in the Instrumentation and Controls Division at the Oak Ridge National Laboratory, in association with the United States Enrichment corporation (USEC), the Navy, and various Department of Energy sponsors, have been involved in the development and application of motor-current signature analysis (CSA) for several years. In that time CSA has proven to not only be useful for manually applied periodic monitoring of electrically driven equipment but it has also been demonstrated to be well suited for dedicated monitoring systems in industrial settings. Recent work has resulted in the development and installation of a system that can monitor up to 640 motor and compressor stages for various aerodynamic conditions in the gas compressors and electrical problems in the drive motors. This report describes a demonstration of that technology installed on 80 stages at each of the two USEC uranium enrichment plants.
Date: January 1, 1996
Creator: Castleberry, K.N.
Partner: UNT Libraries Government Documents Department

Effects of stator and rotor core ovality on induction machine behavior

Description: Asymmetries in the air gap of induction motors produce additional harmonics in the flux density and force waves. A complete transient finite element model analyzes the harmonics produced from two possible asymmetries, a stator core ovality and a rotor ovality. The analysis of the air gap flux density and magnetic force waves determined by the finite element model shows unique harmonic frequencies due to the ovality of the air gap.
Date: September 1, 1996
Creator: Salon, S.J.; Burow, D.W.; DeBortoli, M.J. & Slavik, C.J.
Partner: UNT Libraries Government Documents Department

Digital signal processing control of induction machine`s torque and stator flux utilizing the direct stator flux field orientation method

Description: This paper presents a review of the Direct Stator Flux Field Orientation control method. This method can be used to control an induction motor`s torque and flux directly and is the application of interest for this thesis. This control method is implemented without the traditional feedback loops and associated hardware. Predictions are made, by mathematical calculations, of the stator voltage vector. The voltage vector is determined twice a switching period. The switching period is fixed throughout the analysis. The three phase inverter duty cycle necessary to control the torque and flux of the induction machine is determined by the voltage space vector Pulse Width Modulation (PWM) technique. Transient performance of either the flux or torque requires an alternate modulation scheme which is also addressed in this thesis. A block diagram of this closed loop system is provided. 22 figs., 7 tabs.
Date: April 1, 1997
Creator: Seiz, J.B.
Partner: UNT Libraries Government Documents Department

Efficiency modeling and evaluation of a resonant snubber based soft- switching inverter for motor drive applications

Description: This paper establishes an analytical model for a resonant snubber based soft-switching inverter. The model adopts loss separation method to evaluate losses in individual components. Because of symmetry of the inverter circuit, the developed model is suitable for both single-phase and three-phase inverters. A single-phase inverter was built and tested with a single-phase induction motor driving a fan load to verify the developed model. The equivalent single-phase induction motor model was curve-fitted from experiment. Analytical results showed reasonable agreement with experiment. The same efficiency evaluation method was then applied to the conventional hard-switching inverter, and the results were compared with that of the soft-switching inverter. The resonant snubber base soft-switching inverter shows substantial efficiency improvement over the hard switching PWM (pulse-width-modulation) inverter, especially in low speed operation.
Date: December 31, 1995
Creator: Lai, J.S.; Young, R.W. & Ott, G.W.
Partner: UNT Libraries Government Documents Department

Halbach array motor/generators: A novel generalized electric machine

Description: In August 1979, Halbach submitted a paper entitled ``Design of Permanent Multipole Magnets with Oriented Rare Earth Cobalt Material.`` In this paper, he presented a novel method of generating multipole magnetic fields using non-intuitive geometrical arrangements of permanent magnets. In subsequent publications, he further defined these concepts. Of particular interest to one of the authors (RFP) was the special magnet array that generated a uniform dipole field. In 1990 Post proposed the construction of an electric machine (a motor/generator) using a dipole field based on Klaus Halbach`s array of permanent magnets. He further proposed that such a system should be employed as an integral part of ``an electromechanical battery`` (EMB), i.e., a modular flywheel system to be used as a device for storing electrical energy, as an alternative to the electrochemical storage battery. This paper reviews Halbach`s theory for the generation of a dipole field using an array of permanent magnet bars, presents a simple analysis of a family of novel ``ironless`` electric machines designed using the dipole Halbach array, and describes the results obtained when they were tested in the laboratory.
Date: October 28, 1994
Creator: Merritt, B.T.; Post, R.F.; Dreifuerst, G.R. & Bender, D.A.
Partner: UNT Libraries Government Documents Department

Effects of stator and rotor core ovality on induction machine behavior

Description: Asymmetries in the air gap of induction motors produce additional harmonics in the flux density and force waves. A complete transient finite element model analyzes the harmonics produced from two possible asymmetries, a stator core ovality and a rotor ovality. The analysis of the air gap flux density and magnetic force waves determined by the finite element model shows unique harmonic frequencies due to the ovality of the air gap.
Date: July 1, 1995
Creator: Salon, S.J. & Burow, D.W.
Partner: UNT Libraries Government Documents Department

MOV motor and gearbox performance under design basis loads

Description: This paper describes the results of valve testing sponsored by the US Nuclear Regulatory Commission, Office of Nuclear Regulatory Research and conducted at the Idaho National Engineering and Environmental Laboratory. The research objective was to evaluate the capabilities of specific actuator motor and gearbox assemblies under various design basis loading conditions. The testing was performed using the motor-operated valve load simulator, a test fixture that simulates the stem load profiles a valve actuator would experience when closing a valve against flow and pressure loadings. The authors tested five typical motors (four ac motors and one dc motor) with three gearbox assemblies at conditions a motor might experience in a power plant, including such off-normal conditions as operation at high temperature and reduced voltage. The authors also determined the efficiency of the actuator gearbox. The testing produced the following significant results: all five motors operated at or above their rated torque during tests at full voltage and ambient temperature; for all five motors (dc as well as ac), the actual torque loss due to voltage degradation was greater than the torque loss predicted using common methods; startup torques in locked rotor tests compared well with stall torques in dynamometer-type tests; the methods commonly used to predict torque losses due to elevated operating temperatures sometimes bounded the actual losses, but not in all cases; the greatest discrepancy involved the prediction for the dc motor; running efficiencies published by the manufacturer for actuator gearboxes were higher than the actual efficiencies determined from testing, in some instances, the published pullout efficiencies were also higher than the actual values; operation of the gearbox at elevated temperature did not affect the operating efficiency.
Date: June 1, 1998
Creator: DeWall, K.G.; Watkins, J.C. & Weidenhamer, G.H.
Partner: UNT Libraries Government Documents Department

Test facility for advanced electric adjustable frequency drives and generators of typical industrial ratings. Final technical report

Description: A test facility has been developed, for electric adjustable-speed motors and variable-speed generators, that is unique in US universities in terms of its range (5 to 300 hp currently with 0.1 to 1,000 hp final capability) and flexibility (standard NEMA frame and novel geometry machines can be accommodated). The basic facility was constructed with funding from the Electric Power Research Institute. The instrumentation obtained under this DOE grant has been integrated into the facility which was completed in Fall 1997. The facility has already provided useful studies for DOE, EPRI, as well as several West Coast industries and electric energy utilities.
Date: December 1997
Partner: UNT Libraries Government Documents Department

High-vibration detection using motor current signature analysis

Description: Motor current signature analysis (CSA) has been used for several years as a diagnostic tool for electrical problems in ac, induction motors. Personnel at Oak Ridge National Laboratory have found that CSA can also provide information about system vibrations and imbalances similar to the information provided by an accelerometer. As a result, CSA techniques for monitoring the status of the equipment, such as pumps and compressors, driven by induction motors have been developed and used in dedicated monitoring systems. In this work, researchers have found that CSA responds proportionately to imbalances in rotating equipment and can be used to detect the In high-vibration conditions that can result. This report describes how vibration monitoring with CSA can be implemented and presents test data to support that use.
Date: August 1, 1996
Creator: Castleberry, K.N.
Partner: UNT Libraries Government Documents Department

Design of a variable reluctance asymmetric stepping millimotor

Description: This paper reports on the design, simulation, and preliminary testing of a three phase variable reluctance stepping motor. This motor is pancake-shaped with an overall outside diameter of 8 mm and a height of 3 mm. The outside diameter of the rotor is 4.7 mm. The rotor and stators occupy 2 mm of the height with the remaining 1 mm reserved for a 6:1 planetary gear reductor. The rotor and stators were constructed of Hyperco 50 using conventional miniature machining. The reductor was assembled using copper and PMMA (polymethylmethacrylate) components that were constructed using the LIGA (Lithographic Galvanoformung Abformung) microfabrication process. The maximum measured stall torque of the motor without the reductor is 0.47mNm at 4W and the maximum speed is 2,400 rpm.
Date: June 1, 2000
Partner: UNT Libraries Government Documents Department

The $2000 Electric Powertrain Option-1 Program. Final technical report

Description: This report describes the tasks accomplished as part of Northrop Grumman's TRP $2000 Electric Powertrain Option-1 program. Northrop Grumman has strived to achieve technology advances and development considered as high priority to the success of future electric vehicles. Northrop Grumman has achieved the intent of the program by taking several steps toward reducing the cost of the electric vehicle powertrain, demonstrating technologies in the form of hardware and introducing enhancements into production that are consistent with the needs of the market.
Date: June 1, 1999
Partner: UNT Libraries Government Documents Department