Influence of Copper Shield Structure on 3-D Electromagnetic Field, Fluid and Temperature Fields in End Region of Large Turbogenerator

2013 ◽  
Vol 28 (4) ◽  
pp. 832-840 ◽  
Author(s):  
Huo Feiyang ◽  
Han Jichao ◽  
Li Weili ◽  
Zhou Xingfu ◽  
Zhang Yihuang ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Temperature Fields ◽  
Copper Shield

scholarly journals Influence of Rectifiers on Permanent Magnet Wind Generator Electromagnetic and Temperature Fields

2016 ◽  
Vol 10 (1) ◽  
pp. 205-219
Author(s):  
Qiu Hongbo ◽  
Dong Yu ◽  
Yang Cunxiang
Keyword(s):  
Electromagnetic Field ◽  
Temperature Field ◽  
Permanent Magnet ◽  
Core Loss ◽  
Harmonic Distortion ◽  
Temperature Fields ◽  
Stator Core ◽  
Current Harmonics ◽  
Copper Loss ◽  
Wind Generator

Power rectifiers are very necessary in the wind power generation systems since they are the necessary channels that link the generator and power gird together. However, they have some effects on the permanent magnet wind generator due to their work on fast on-off transitions. Taking an 8kW 2000r/min wind-driven permanent magnet generator as an example, the system model and external circuit were established. Firstly, based on the field-circuit coupling calculation method, the voltage and current harmonics have been studied respectively when the generator was connected to rectifier loads and pure resistance loads, so did the total harmonic distortion. The mechanism of harmonic impacted by rectifiers was revealed. Secondly, combined the harmonic electromagnetic field theory, the stator core loss, armature winding copper loss and rotor eddy loss were analyzed when the generator connected different loads. Furthermore, according to the definition of nonlinear circuits PF, the numerical analysis method was adopted to calculate the power factor when the generator connected two loads respectively. The change mechanism of PF impacted by rectifiers has been revealed. In addition, the temperature field model has been established and the generator temperature was also analyzed. The temperature distributions were obtained when the wind generator was connected to different loads. Then, the relationship between losses and temperature was combined, the change rules of permanent magnet temperature by the eddy current loss were studied under different load. At last, it can prove that the rectifiers have influences on both electromagnetic field and temperature field through comparing the simulation results with experimental test data.

scholarly journals Experimental Research of Electromagnetic Field Influence on Digital Temperature Sensors with Single-Wire Lines to Study Possibility of Their Use in NPP Control Systems

2019 ◽  
pp. 14-18
Author(s):  
Yu. Bykovsky ◽  
V. Levchenko ◽  
O. Pogosov
Keyword(s):  
Electromagnetic Field ◽  
Temperature Sensors ◽  
Operating Conditions ◽  
Temperature Fields ◽  
Auxiliary Equipment ◽  
New Approach ◽  
Metrological Control ◽  
Control Technologies ◽  
Technical Interest ◽  
And Control

Issues related to the introduction of new control technologies and temperature monitoring at NPPs are being considered, since NPP longterm operation depends on the reliability of process control means. It is promising to build instrumentation and control complexes using one-wire technologies, since the operation information removal and transmission means should be carried out under the conditions of spatial constraints on the location of cabling. One-wire technologies make it easy to build a measurement network of the most complex topology. It is proposed to use DS18B20 universal digital primary measuring transducers as NPP testing equipment. In this regard, scientific and technical interest is a new approach to the measurement of temperature fields based on 1-Wire technology. It was proposed to use UR-1 demagnetizer as a source of a variable electromagnetic field imitating NPP equipment operating conditions. The paper also presents a study for visualization of the generated electromagnetic fields. A Hall sensor is used for measuring the fields under consideration. The proposed method can be used to conduct other similar studies to assess the response of temperature sensors (or other digital sensors) to an external magnetic field. A visualization method is used to evaluate the informational function and a conclusion is made about the applicability of such sensors in the systems of metrological control and monitoring of NPP auxiliary equipment.

scholarly journals Modeling and Analysis of Electromagnetic Field and Temperature Field of Permanent-Magnet Synchronous Motor for Automobiles

Electronics ◽  
2021 ◽  
Vol 10 (17) ◽  
pp. 2173
Author(s):  
Meixia Jia ◽  
Jianjun Hu ◽  
Feng Xiao ◽  
Ying Yang ◽  
Chenghao Deng
Keyword(s):  
Electromagnetic Field ◽  
Temperature Field ◽  
Permanent Magnet ◽  
Permanent Magnet Synchronous Motor ◽  
Coupling Model ◽  
Synchronous Motor ◽  
Temperature Fields ◽  
Modeling And Analysis ◽  
Electromagnetic Model ◽  
Bidirectional Coupling

In order to study the interaction of electromagnetic fields and temperature fields in a motor, the iron loss curve at different frequencies of silicon steel and the B-H curve at different temperatures of the permanent magnet (PM) were obtained to establish the electromagnetic model of the permanent magnet synchronous motor (PMSM). Then, unidirectional and bidirectional coupling models were established and analyzed based on the multi-physical field. By establishing a bidirectional coupling model, the temperature field distribution and electromagnetic characteristics of the motor were analyzed. The interaction between temperature and electromagnetic field was studied. Finally, the temperature of the PMSM was tested. The results showed that the bidirectional coupling results were closer to the test result because of the consideration of the interaction between electromagnetic and thermal fields.

scholarly journals Research on Electromagnetic Field, Eddy Current Loss and Heat Transfer in the End Region of Synchronous Condenser with Different End Structures and Material Properties

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4636
Author(s):  
Xiaoshuai Bi ◽  
Likun Wang ◽  
Fabrizio Marignetti ◽  
Minghao Zhou
Keyword(s):  
Heat Transfer ◽  
Electromagnetic Field ◽  
Eddy Current ◽  
Three Dimensional ◽  
Eddy Current Loss ◽  
Transfer Model ◽  
Current Loss ◽  
Synchronous Condenser ◽  
Transient Electromagnetic ◽  
Copper Shield

Aiming at the problem of end structure heating caused by the excessive eddy current loss of large synchronous condensers used in ultra-high voltage (UHV) power transmission, combined with the actual operation characteristics of the synchronous condenser, a three-dimensional transient electromagnetic field physical model is established, and three schemes for adjusting the end structure of the condenser under rated condition are researched. The original structure has a copper shield and a steel clamping plate. Scheme 1 has no copper shield but has a steel clamping plate. Scheme 2 has no copper shield but has an aluminum clamping plate. By constructing a three-dimensional fluid–solid coupling heat transfer model in the end of the synchronous condenser, and giving the basic assumptions and boundary conditions, the eddy current loss of the structure calculated by the three schemes is applied to the end region of the synchronous condenser as the heat source, and the velocity distribution of the cooling medium and the temperature distribution of each structure under the three different schemes are obtained. In order to verify the rationality of the numerical analysis model and the effectiveness of the calculation method, the temperature of the inner edge of the copper shield in the end of the synchronous condenser is measured, and the temperature calculation results are consistent with the temperature measurement results, which provides a theoretical basis for the electromagnetic design, structural optimization, ventilation and cooling of the synchronous condenser.

scholarly journals Improving the Reliability of Rotary Furnace Drums By Stabilizing the Temperature Regime By Effect of Electromagnetic Fields

2020 ◽  
Author(s):  
Yuri Vladimirovich Mikhailov ◽  
Alexander Alexandrovich Rukomoinikov ◽  
Rinat Gazizyanovich Abdeev ◽  
Eldar Rinatovich Abdeev
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Fields ◽  
Direct Contact ◽  
Rotary Furnace ◽  
Combustion Products ◽  
Heat Fluxes ◽  
Temperature Fields ◽  
Premature Failure ◽  
Main Factors ◽  
Rotary Kilns

The unevenness of the heat flow generated in the furnaces of the drums of rotary kilns leads to damage to the drum casing, which can cause premature failure. The author suggests that by deflecting the flame by applying electromagnetic fields, it is possible to prevent direct contact between the flame and the furnace drum, extending the latter’s service life. In this way, it is possible to regulate the directions of movement of the heated combustion products to realize the uniform distribution of heat fluxes, as well as to regulate local temperature fields in real time. The study took into account 5 main factors of the influence of the electromagnetic field on the flame. Based on the studies, a description of a device partially integrated in the furnace is proposed. In this case, there is no significant constructive modernization of the furnace. This device is an analogue of a high-temperature fan, but has several advantages in comparison with it. Keywords: electromagnetic field, furnace, flame, heat exchange

scholarly journals Features of heating technology at induction thermal processing with external electromagnetic field

2020 ◽  
Vol 65 (1) ◽  
pp. 54-61
Author(s):  
I. I. Vegera ◽  
A. V. Zizika ◽  
P. Y. Tsykunou ◽  
V. M. Yakovich
Keyword(s):  
Electromagnetic Field ◽  
Magnetic Circuit ◽  
Heating Temperature ◽  
Hardened Layer ◽  
Temperature Fields ◽  
Effect Of Temperature ◽  
Design Stage ◽  
Rigid Base ◽  
Total Width ◽  
Flat Part

According to the data of performed calculations and modeling of the hardening process, a design of inductors with magnetic cores for hardening long flat parts has been developed. At the design stage of this type of inductors, it was necessary to find out the degree of influence of the magnetic circuit design on the distribution of the temperature field during heating. To do this, we simulated electromagnetic and temperature fields to assess the concentration of the electromagnetic field at different heights of the “legs” of the inductor. As a result, a significant effect of the length of the “legs” of the magnetic circuit on the intensity of heating and the operability of the system as a whole was established. It is noted that insufficient height of the “leg” leads to a significant decrease in the field concentration, which leads to insufficient heating temperature and uneven distribution of heat zones in the heated part. In turn, an increase in the height of the “legs” leads to a narrowing of the heat release zone in the part compared to the total width of the coil and magnetic circuit. With a significant lengthening of the “legs”, the cooling circuit of the inductor will not be able to remove heat from the magnetic circuit obtained from the part, which will lead to the destruction of the magnetic circuit. The developed design of a two-turn single-circuit inductor and the general methodology made it possible to obtain a high-quality hardened layer with a depth of up to 3 mm with the formation of a martensitic structure of the required hardness on a planar-type flat part without significant energy loss. The part was machined by fixing it on a rigid base to compensate for the effect of temperature changes in linear dimensions. To obtain a uniform gap between the part and the inductor, a special pressure roller was used. The resulting structure of the hardened layer adequately meets the stated requirements for the part. The results of the research were used to develop a flat part of the “guide” type for lifting equipment (for example, a guide for the movement of the traction chain) and were introduced into production.

The growth of mica polytypes as studied by conventional and high-resolution TEM

1983 ◽  
Vol 41 ◽  
pp. 174-177
Author(s):  
A. Baronnet ◽  
M. Amouric
Keyword(s):  
Water Pressure ◽  
Point Of View ◽  
Temperature Fields ◽  
Natural Occurrence ◽  
Growth Mechanisms ◽  
Long Period ◽  
High Resolution Tem ◽  
Layer Stacking ◽  
Experimental Works ◽  
Potential Use

The origin of mica polytypes has long been a challenging problem for crystal- lographers, mineralogists and petrologists. From the petrological point of view, interest in this field arose from the potential use of layer stacking data to furnish further informations about equilibrium and/or kinetic conditions prevailing during the crystallization of the widespread mica-bearing rocks. From the compilation of previous experimental works dealing with the occurrence domains of the various mica "polymorphs" (1Mr, 1M, 2M1, 2M2 and 3T) within water-pressure vs temperature fields, it became clear that most of these modifications should be considered as metastable for a fixed mica species. Furthermore, the natural occurrence of long-period (or complex) polytypes could not be accounted for by phase considerations. This highlighted the need of a more detailed kinetic approach of the problem and, in particular, of the role growth mechanisms of basal faces could play in this crystallographic phenomenon.

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