High Efficiency Induction Research Articles

고효율 유도전동기용 프로토 타입 금형 설계 및 제작에 관한 연구

고효율 유도전동기 금형기술은 고효율 유도전동기의 핵심 부품인 코어(철심)의 제조를 위한 핵심기술이며, 전동기 산업분야의 국가경쟁력 제고를 위해서는 필수적으로 확보하여야 하는 기술 이다. 본 논문에서는 고효율 유도 전동기용 코어를 소형과 대형의 2벌의 프로토 타입 금형으로 설계 및 제작하여 프레스에 장착하여 시험타출하였고 그 결과를 고찰하였다. The die technology of a high-efficiency induction motor is an important technology for manufacturing the core (iron core), which is the major part of a high-efficiency induction motor. It is also an essential technology in enhancing national competitiveness. In this study, the core of a high-efficiency induction motor was designed and manufactured as 2 prototype dies: one is for small-size, and the other is for large-size. They are then tested by attaching in press, the result are considered.

Development of Induction Heater Hot Water System using New Active Clamping Quasi Resonant ZVS PWM Inverter

This paper presents a new conceptual electromagnetic induction eddy current based stainless steel plate spiral type heater for heat exchanger or dual packs heater in hot water system boiler steamer and super heated steamer, which is more suitable and acceptable for new generation consumer power applications. In addition, an active clamping quasi-resonant PWM high frequency inverter using trench gate IGBTs power module can operate under a principle of zero voltage soft commutation with PWM is developed and demonstrated for a high efficient induction heated hot water system and boiler in the consumer power applications. This consumer induction heater power appliance using active clampillg soft switching PWM high frequency inverter is evaluated and discussed on the basis of experimental results.

Galvanizing pre‐treatment with hydrogen

PurposeBefore being galvanized, long products like tube, wire and strip need to be cleaned to remove oils and oxides that would inhibit the galvanizing process. Ideally, this process would be instantaneous so that production rates were not compromised and would require no energy. The purpose of this paper is to describe an investigation where rapid induction heating was combined with counter current flow of a hydrogen‐rich atmosphere to reduce and evacuate surface oxides and residual drawing compounds before continuous galvanizing.Design/methodology/approachExperiments were carried out to simulate the continuous hot‐dip galvanizing of steel wire.FindingsThe results suggested that, under the experimental conditions, lightly oxidized layers could be reduced in less than 2 s and give galvanized layers with good adhesion. High efficiency induction heating minimized the energy input required.Originality/valueThe use of this technology can maximize galvanizing line speeds while maintaining quality with the minimum environmental impact.

THE EFFICIENT INDUCTION OF EMBRYOGENIC CALLUS AND HIGH FREQUENT SOMATIC EMBRYOGENESIS OF IN VITRO CULTURE OF BER

Some important factors effect on in vitro regeneration of ber (Zizyphus mauritiana Lam.) were researched in our experiments. A system of high efficient embryogenic callus induction and somatic embryogenesis was established. The main results are as follows: (i) the types and conditions of explants are very important to culturing availability. Immature embryos or tender leaves are much suitable for regeneration than other tissues or organs. (ii) Immature embryos cultured on MS+TDZ 0.05 mg/L+PP333 0.5 mg/L+AgN0 3 10 mg/L+Vc 100 mg/L+sucrose 30 g/L are facilitated to generate embryogenic calli, these calli spontaneously proceeded to high frequent somatic embryogenesis, whereas the tender leaves from adult tree just produced embryogenic calli on this medium; thus, an extra subculture on MS+KT 4.0 mg/L+NAA 0.03 mg/L+sucrose 50 g/L is necessary to start the somatic embryogenesis for the leaf derived calli. (iii) The somatic embryoids from the above origins could proliferate vigorously on MS+TDZ 0.05 mg/L+PP333 0.5 mg/L+AgNO 3 10 mg/L+Vc 100 mg/L+Ac 3.0 g/L+sucrose 30 g/L. Finally, some developed embryoids could normally germinate and convert to whole plantlets on MS+KT 1.0 mg/L+6-BA 1.0 mg/L+NAA 0.2 mg/L+GA 3 2.0 mg/L+AC 2.0g/L+sucrose 30 g/L after 6 day's dehydrating. Ber is a very short juvenile-period woody fruit (only about six months); the establishment of somatic embryogenesis and plant regeneration would settle a good foundation for micropropagation or transgenic researches for this species.

Enhancer-specified GFP-based FACS purification of human spinal motor neurons from embryonic stem cells

Human embryonic stem (hES) cells may generate all major somatic cell types, yet no neuronal subtype has yet been specifically generated in useful purity from hES culture. We report here the selective induction and isolation of functional spinal motor neurons (MNs) from human ES cells. hES cells of the H1 line were transfected with plasmids encoding GFP placed under the control of an MN-specifying enhancer within the 5′-regulatory region of the gene encoding the transcription factor Hb9 and treated with sonic hedgehog (Shh) and retinoic acid (RA). As MNs were induced under the influence of Shh and RA, they activated Hb9-driven GFP expression, permitting their isolation by fluorescence-activated cell sorting (FACS). The MNs thereby generated and isolated became cholinergic and achieved functional maturation in vitro, as evidenced by their fast sodium currents and action potentials on whole-cell patch-clamp and α-bungarotoxin-identified clustering of AChR receptors on co-cultured skeletal myoblasts. The serial combination of these two approaches, motor neuron phenotypic induction followed by Hb9 enhancer-based FACS, permitted the high-efficiency induction and isolation of functional motor neurons from hES cells. These results suggest the utility of promoter/enhancer-based FACS for the isolation of specific phenotypes from hES cell populations as a means of purifying clinically appropriate vectors for cell therapy.

Microstructures and Electrical Conductivity of Cu-Ca Alloys for High Efficiency Induction Motors

The microstructures and electrical conductivity of newly developed Cu-Ca alloys for semi-solid forming have been investigated. High purity calcium was added to molten copper up to 1.4% by weight and mold-cast into a rod. Thermomechanical treatment (TMT) has been carried out to evaluate the variation in electrical conductivity and microstructures of Cu-Ca alloys. The electrical conductivity of copper was reduced linearly with the concentration of calcium by , where k is a constant having the values ranging from 16.7 to 20, depending on the processing condition. The introduction of prestrain significantly reduced the grain size during subsequent heating by recrystallization, influencing the electrical conductivity of Cu-Ca alloys.

繰り返し火花放電を用いた高周波誘導熱プラズマ初期点火の改善とその基礎特性

We have been developing a high efficiency and compact induction thermal plasma torch using a static induction transistor inverter in the frequency range of 0.5∼1.5MHz. The ignition of an initial plasma is assisted by spark discharges using an automobile spark plug. The use of spark discharges makes the ignition of the induction plasma reproducible and stable. The threshold rf current of the induction coil required for start-ups is strongly reduced to be about half of that without spark discharges. The rf voltage and current measurement in the rf inverter circuit shows that more than 80% of the generated rf power is consumed to sustain argon thermal plasmas at the atmospheric pressure.

Embryogenic response of multiple soybean [Glycine max (L.) merr.] cultivars across three locations

Nine soybean [Glycine max (L.) Merr.] cultivars representing midwestern, mid-south, and southern US growing regions were evaluated at each of three locations (Athens, GA; Lexington, KY; and Wooster, OH) using uniform embryogenic induction and proliferation protocols in order to evaluate the portability of soybean somatic embryogenic protocols to different locations. The experimental design minimized variation between locations by having all cultivars present at all locations on all days. A quantitative weighted score for primary embryo induction was developed on average embryo number per explant and was used to describe non-embryogenic, poorly embryogenic, moderately embryogenic, and highly embryogenic responses. Ranking of cultivars remained similar across all locations, indicating a uniform transportability of the protocol, at least as far as embryo induction is concerned. Continued proliferation of embryogenic cultures was also measured using a repetitive growth measure but few meaningful conclusions could be made due to the high level of variability including inconsistent growth of cultures between each subculture. Overall, several cultivars were identified as being uniformly embryogenic or non-embryogenic at the primary induction phase at all locations, and we predict that those embryogenic cultivars could be used by any laboratory for high-efficiency induction of embryogenesis. The best of these cultivars, ‘Jack’, was uniformly responsive across all locations and should be selected as the genotype most likely to yield positive results when attempting to culture and genetically engineer soybeans via embryogenic protocols.

High-efficiency induction of soybean hairy roots and propagation of the soybean cyst nematode.

Cotyledon explants of 10 soybean [Glycine max (L.) Merr.] cultivars were inoculated with Agrobacterium rhizogenes strain K599 with and without binary vectors pBI121 or pBINm-gfp5-ER possessing both neomycin phosphotransferase II (nptII) and beta-glucuronidase (gus) or nptII and green fluorescent protein (gfp) genes, respectively. Hairy roots were produced from the wounded surface of 54-95% of the cotyledon explants on MXB selective medium containing 200 microg ml(-1) kanamycin and 500 microg ml(-1) carbenicillin. Putative individual transformed hairy roots were identified by cucumopine analysis and were screened for transgene incorporation using polymerase chain reaction. All of the roots tested were found to be co-transformed with T-DNA from the Ri-plasmid and the transgene from the binary vectors. Southern blot analysis confirmed the presence of the 35S-gfp5 gene in the plant genomes. Transgene expression was also confirmed by histochemical GUS assay and Western blot analysis for the GFP. Attempts to induce shoot formation from the hairy roots failed. Infection of hairy roots of the soybean cyst nematode (Heterodera glycines Ichinohe)-susceptible cultivar, Williams 82, with eggs of H. glycines race 1, resulted in the development of mature cysts about 4-5 weeks after inoculation. Thus the soybean cyst nematode could complete its entire life cycle in transformed soybean hairy-root cultures expressing GFP. This system should be ideal for testing genes that might impart resistance to soybean cyst nematode.

Novel high-speed induction motor for a commercial centrifugal compressor

This paper describes the electrical, mechanical and metallurgical design, construction and testing of a novel, low-cost, high-speed, high-efficiency induction motor to drive a new type of small centrifugal compressor in industrial cooling applications. The 28 shaft HP, 50 krpm motor features a unique laminated rotor with a multi-function, high-strength copper alloy cage brazed with a novel process. Relatively thin, high-silicon steel laminations were used to achieve low losses and high mechanical strength at low cost. Different heat-treatments for the stator and rotor laminations were used to optimize the mechanical and magnetic properties. The pre-prototype motors achieved about 94% (electromagnetic) efficiency at the rated point, including inverter harmonics, while meeting cost (less than one tenth of aerospace practice) and produceability goals.

Large low-cost single-phase SEMIHEX/sup TM/ motors

These low-cost single-phase motors are 3-phase high efficiency induction motors with the SEMIHEX/sup TM/ connection of the windings to 2 run capacitors. The single-phase winding currents at full load are the same as if the motors were connected to a 3-phase source. The single-phase full-load efficiencies are the same as the 3-phase efficiencies. The line starting current is unity power factor and is approximately two times the full-load current for motors between 10 HP and 100 HP.

Improved low loss high permeability grades, processing and properties

Non-oriented electrical steels are sub-divided into 'fully processed' and semi-processed' types. The hystory of loss reduction has generally been associated with silicon additions for both types of steel which unfortunately is detrimental to high field permeability. More recently. the availability of ultra low carbon and ultra low sulphur steels has permitted a shift in the loss/permeability compromise associated with silicon addition by adopting a lean and clean approach in which losses are lowered by improved purity and, perhaps, thickness selection whilst good high field permeability is maintained by a restriction on silicon additions. This paper deals with recently developed steels of this type. particularly 'Polycor' aimed at the high efficiency induction motor market. The changing role of insulative coatings on new materials is also considered. Potential further development of low loss high permeability grades is discussed.

Asymmetric bipolar pulsed power: a new power technology

There is increasing commercial interest in processes involving reactive PVD deposition of insulating films, including deposition of wear resistant coatings; insulating films for microcircuits (including devices such as thin films heads) or electronic devices such as capacitors; sophisticated architectural glass coatings; coatings on polyester film for architectural glass laminates or oxygen barriers for food packaging; heat reflecting coatings for high efficiency lamps or induction furnace heat shields; deposition of barrier and functional layers for flat panel displays, including the ITO glass used in LCD displays; and myriad other similar functional and decorative applications. Reactive sputtering using single cathodes and pulsed dc power has been used, and satisfactory results obtained. An intrinsic problem with single targets, however, is related to the coating of the anode with the deposited insulator, a problem solved by using dual sources. Dual target systems can use sinusoidal power, but increased flexibility is obtained using pulsed power and multiple cathodes. This article describes the power supply technology required for pulsed multiple cathode sputtering, and describes a new pulsed power supply which has been developed for dual cathode sputtering.

On the energy optimized control of standard and high-efficiency induction motors in CT and HVAC applications

This paper contains an analysis of how the choice of energy optimal control of induction motors is influenced by motor construction, standard versus high-efficiency motor, and by application, constant torque (CT) and heating, ventilation, and air conditioning (HVAC) (interpreted as vector and scalar motor drives). The analysis is made with a 2.2 kW voltage-source-inverter-fed squirrel-cage motor drive as an example throughout the paper, but through statistics on the use of motors and their efficiencies, the conclusions are widened to a broader range (0-50 kW). Energy optimal control strategies are reviewed and cos(/spl thetav/) control, a model-based control, and a search control are implemented in the laboratory in a vector and a scalar motor drive. The convergence speed for the strategies and their ability to reject disturbances are investigated by experiments. It is also shown experimentally that, for both standard and high-efficiency motors, motor energy-efficiency improvement is achievable by energy optimal control below 60% load torque. The energy savings using energy optimal control strategies are measured on a pump system with a certain load cycle. Model-based control is recommended for CT applications and cos(/spl thetav/) control for HVAC applications.

High efficiency induction of papillomas in vivo using recombinant cottontail rabbit papillomavirus DNA

Plasmids containing cottontail rabbit papillomavirus (CRPV) DNA can induce papillomas in vivo, but efficiency has been low. The aim of the present investigation was to explore some of the technical variables involved in inoculation of rabbits with recombinant CRPV DNA in attempts to improve both yield and consistency of papilloma induction. It was found that induction of epidermal hyperplasia, with either a mixture of turpentine and acetone or phorbol esters, produced a marked increase in papilloma yield. An additional powerful factor was the use of very vigorous, cutaneous scarification, sufficient to penetrate the papillary dermis and produce bleeding. When used in combination, papilloma yields were consistent and often reached 90-100% of inoculated sites. A number of other variables which did not consistently affect papilloma yield were tested. These included bleb and puncture injections, plasmid dose, vector type, occlusive dressings, lipofection reagent, carrier DNA, and different methods for plasmid DNA extraction and purification. It is concluded that the most important variables in improving papilloma yields were prior induction of epidermal hyperplasia and vigorous cutaneous scarification.

Analysis of induction skull melting furnace by edge finite element method excited from voltage source

To optimize the production of high-efficiency induction skull melting furnace, we analyzed magnetic flux density, eddy current and electromagnetic force distributions using the 3D edge-based finite element method excited from a voltage source. Changing the number of copper rods and, therefore, the distance between them, we analyzed both the intensity and direction of the electromagnetic forces and the amount of power consumed by the molten alloy and the rods. In this paper, we present our analysis method, the obtained results and conclusions. >

Losses due to rotational flux in three phase induction motors

This paper discusses rotational losses and how they are produced in the core materials of induction motors. These losses are largely caused by flux that rotates in the plane of the machine laminations. This suggests that steel specification for applications to rotating machines should be given in terms of rotational loss data as a material characteristic, in much the same fashion as Epstein test results are provided for alternating losses. If a standardized test for rotational losses were to be used, steel producers could rationally investigate the effects of composition and processing variables. This is necessary in order to produce low loss steels for motor applications. Reduction of rotational losses in motor cores could significantly lower AC machine operating costs and contribute to the growing interest and design of high efficiency induction motors. The paper describes a test procedure for determining rotational losses in a sample. It then compares the results with standardized tests from an Epstein test procedure. It is seen that there are significant differences in loss results obtained for the rotational test versus the alternating current test. The authors have investigated a time harmonic finite element formulation utilizing Magnet 2D, a commercially available package. The paper includes a brief analysis of a typical problem using this tool.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The pTiC58 tzs gene promotes high-efficiency root induction by agropine strain 1855 of Agrobacterium rhizogenes

Root induction on flax (Linum usitatissimum L.) cotyledon explants by Agrobacterium rhizogenes strain 1855 is markedly increased by co-inoculation with disarmed A. tumefaciens strain LBA 4404 containing a plasmid carrying the tzs gene of pTiC58. Most of the roots (estimated to be more than 90%) were transformed. This effect is most likely due to the secretion of trans-zeatin by A. tumefaciens stimulating the division of plant cells making them more receptive to transformation by A. rhizogenes, although other explanations are possible. This observation supports the idea that the tzs gene, although not essential for transformation, may promote transformation. An obvious application for genetic engineering experiments involving transformation by A. rhizogenes, is to include a vir-induced tzs gene in the transformation system to help maximize transformation efficiency.

A nonimmunosuppressive helper virus allows high efficiency induction of B cell lymphomas by reticuloendotheliosis virus strain T.

We have documented the effect of two nondefective helper viruses, reticuloendotheliosis virus A (REV-A) and chick syncytial virus (CSV) infection on bursal tissue. REV-A infection results in bursal atrophy, destroying both its structural and functional integrity. In contrast, the bursae in CSV-infected chicks, while reduced slightly in size, appear both structurally and functionally normal. REV-A-induced bursal atrophy is not a result of viral replication in the B-lymphocyte as (a) both viruses are capable of inducing, with equal efficiency, the formation of preneoplastic lesions containing proliferating B lymphocytes and (b) it appears that equivalent amounts of viral antigen are expressed in the bursae of chicks infected with either virus. We have examined the phenotype of tumors induced by the replication-defective virus REV-T when replicated by the two different helper viruses, REV-A and CSV. In REV-T(REV-A)-infected chicks, the majority of tumors that develop are negative for IgM expression. In contrast, the majority of tumors induced by REV-T(CSV) infection are IgM+. This finding is confirmed by recovery of IgM- cell lines from REV-T(REV-A)-infected chicks and IgM+ cell lines from REV-T(CSV)-infected chicks. In addition, repopulation studies show that bursal-derived cells that are IgM+ serve as target cells for REV-T(CSV)-induced lymphomas. This study demonstrates, therefore, that REV-T can induce IgM+, B cell lymphomas with high efficiency. We conclude that infections by the helper viruses, REV-A and CSV, differ dramatically in their effects on the composition of the population of cells that serve as targets for REV-T-induced neoplasia.

An adaptively controlled high-efficiency induction heating system using power MOSFET inverter.

An adaptively controlled high-efficiency induction heating system using power MOSFET inverter.