scholarly journals Static Eccentricity Fault Analysis of Surface-Mounted Permanent Magnet Electromotor with Skewed Slots Based on 2D FEA

2021 ◽  
Vol 12 (4) ◽  
pp. 176
Author(s):  
Li Wang
Keyword(s):  
Magnetic Field ◽  
Electric Vehicle ◽  
Electromotive Force ◽  
Three Dimensional ◽  
Fault Analysis ◽  
Average Value ◽  
Wheel Drive ◽  
Study Results ◽  
Calculation Results ◽  
Air Gap Magnetic Field

It is of significance to analyze the performance of eccentric electromotor for the research on the electric vehicle wheel drive system’s operational reliabilities. We developed a fast equivalent algorithm in which the two-dimensional finite element calculation results are translated into three-dimensional calculation results. An electromotor with skewed slot was decomposed into straight-slot electromotor units that were series-wound. A prototype electromotor driven by square wave current under healthy and eccentric conditions was calculated, and the computation accuracy of the equivalent algorithm was analyzed. The air-gap magnetic field and induced electromotive force were calculated and contrasted. The study results indicate that the magnetic field distribution and the induced electromotive forces of winding elements with different axis positions were affected transparently by grievous eccentricity, yet the induced electromotive force of one phase winding and average value of torque remained virtually invariable. The reference to reliability analysis of electric vehicle wheel drive system is provided.

scholarly journals Multifield Calculation and Analysis of Excitation Winding Interturn Short Circuit Fault in Turbo-Generator

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2626 ◽  
Author(s):  
Minghan Ma ◽  
Yonggang Li ◽  
Yucai Wu ◽  
Chenchen Dong
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Temperature Field ◽  
Stress Field ◽  
Short Circuit ◽  
Three Dimensional ◽  
Turbo Generator ◽  
Dimensional Finite Element ◽  
Air Gap Magnetic Field ◽  
Excitation Winding

Excitation winding interturn short circuit (EWISC) is a common fault in turbo-generators. Once the fault occurs, if not handled in time, it will result in significant security risks to the power system. Using the multifield characteristics of fault generators for a comprehensive diagnosis can make the diagnostic results more accurate and credible. In this paper, taking a TA-1100-78 type, two pole pairs turbo-generator as the research object, the two-dimensional finite element electromagnetic model of stator/rotor and the three-dimensional finite element heat transfer model of rotor were established. The electromagnetic field, temperature field, and stress field of the generator were simulated and analyzed. At the same time, the air gap magnetic field, three-dimensional temperature field, and stress field distribution of the rotor were calculated for EWISC faults in different fault degrees and positions. The results showed that the EWISC fault weakened the air gap magnetic field and caused unbalanced electromagnetic distribution. At the same time, it caused a distortion of the rotor temperature field, resulting in an unbalanced distribution of the temperature field. The stress field was affected by the distortion of temperature field, and the local thermal stress increased but did not exceed the yield limit of the material. Restorable elastic deformation occurred when the rotor was heated, which caused the thermal bending of the rotor. The method adopted in this paper can provide a reference for the calculation of multiphysical field after a generator fault. It is also pointed out that the thermal unbalance influence should not be neglected in the study of generator vibration characteristics.

scholarly journals Improving Students’ Speaking Skill Through Drama at the Eighth Grade of SMPN 9 Palopo

2020 ◽  
Vol 1 (1) ◽  
pp. 41-54
Author(s):  
Marwati ◽  
Syamsudarni
Keyword(s):  
Data Analysis ◽  
Student Speech ◽  
Average Value ◽  
Study Results ◽  
8Th Grade ◽  
Post Test ◽  
Calculation Results ◽  
Speaking Skill ◽  
And Control ◽  
Better Than

This paper dealt with the effectiveness of drama techniques in enhancing student speech at SMPN 9 Palopo in 8th grade. The research was mainly sample. This investigation was carried out in two classes: experimental and control classes. Sixty students from VIII SMPN 9 Palopo graduates attended this research. The sample of research for the level of VIII 6 was 30 students as experimental classes, and the class of 8 / 1 was composed of 30 students. The method is voice check-in research. The students will be evaluated and assessed by this study. SPSS, 20, analyzed the data. Data were analyzed. The study results show that the use of dramatic materials can improve the skills of speakers. The calculation results show that the scores of students in the experimental class are better than the scores of students in the control class. Based on data analysis, a post-test average value of 10,5300 > 7,5700 is higher than the pre-test average. The average value in the control class is also more significant than the average preliminary value. Based on the analysis of the data, the lesson of speech using effective dramatic techniques at 9 Palopo can be concluded. It can be concluded. The results of the experimental classes can be shown that they are higher than the control class.

Comparative study of thrust of U-shaped ironless permanent magnet synchronous linear motor based on analytical method and finite element analysis

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1091-1101
Author(s):  
Zhihui Yang ◽  
Ren Liu ◽  
Bin Xia
Keyword(s):  
Magnetic Field ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Permanent Magnet ◽  
Edge Effect ◽  
Three Dimensional ◽  
Linear Motor ◽  
Air Gap ◽  
Element Analysis ◽  
Air Gap Magnetic Field

Due to the large transverse edge effect for U-shaped ironless permanent magnet synchronous linear motor affect the distribution of air gap magnetic field is large, it will reduce the no-load back electromotive force and thrust. This paper proposes a novel method to evaluate the effect of transverse edge effect based on Kriging surrogate model. By comparing the results of the two-dimensional and three-dimensional finite element analysis of the air gap magnetic field of the motor, it can be seen transverse length of the motor, air gap height and thickness of the permanent magnet are the main influencing factors.

A novel analytical calculation of magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping

2020 ◽  
pp. 1-15
Author(s):  
Jianqi Li ◽  
Yu Zhou ◽  
Jianying Li
Keyword(s):  
Magnetic Field ◽  
Conformal Mapping ◽  
Permanent Magnet ◽  
Flux Density ◽  
Analytical Method ◽  
Electromotive Force ◽  
Analytical Calculation ◽  
Air Gap ◽  
Permanent Magnet Machines ◽  
Peak Value

This paper presented a novel analytical method for calculating magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping. Firstly, flux density without slots and complex relative air-gap permeance of slotted air gap are derived from conformal transformation separately. Secondly, they are combined in order to obtain normalized flux density taking account into the slots effect. The finite element (FE) results confirmed the validity of the analytical method for predicting magnetic field and back electromotive force (BEMF) in the slotted air gap of spoke-type permanent-magnet machines. In comparison with FE result, the analytical solution yields higher peak value of cogging torque.

Analysis of Characteristics of Halogen and LED Automobile Lamps

2020 ◽  
pp. 57-62
Author(s):  
Olga Yu. Kovalenko ◽  
Yulia A. Zhuravlyova
Keyword(s):  
Power Consumption ◽  
Flip Chip ◽  
Weather Conditions ◽  
Luminous Flux ◽  
Luminous Efficacy ◽  
Colour Temperature ◽  
Study Results ◽  
Calculation Results ◽  
Mandatory Rules ◽  
Halogen Lamps

This work contains analysis of characteristics of automobile lamps by Philips, KOITO, ETI flip chip LEDs, Osram, General Electric (GE), Gtinthebox, OSLAMPledbulbs with H1, H4, H7, H11 caps: luminous flux, luminous efficacy, correlated colour temperature. Characteristics of the studied samples are analysed before the operation of the lamps. The analysis of the calculation results allows us to make a conclusion that the values of correlated colour temperature of halogen lamps are close to the parameters declared by manufacturers. The analysis of the study results has shown that, based on actual values of correlated colour temperature, it is not advisable to use LED lamps in unfavourable weather conditions (such as rain, fog, snow). The results of the study demonstrate that there is a slight dispersion of actual values of luminous flux of halogen lamps by different manufacturers. Maximum variation between values of luminous flux of different lamps does not exceed 14 %. The analysis of the measurement results has shown that actual values of luminous flux of all halogen lamps comply with the mandatory rules specified in the UN/ECE Regulation No. 37 and luminous flux of LED lamps exceeds maximum allowable value by more than 8 %. Luminous efficacy of LED lamps is higher than that of halogen lamps: more than 82 lm/W and lower power consumption. The results of the measurements have shown that power consumption of a LED automobile lamp is lower than that of similar halogen lamps by 3 times and their luminous efficacy is higher by 5 times.

PENERAPAN PEMBELAJARAN MATEMATIKA REALISTIK INDONESIA (PMRI) UNTUK MENINGKATKAN HASIL BELAJAR MATEMATIKA SISWA KELAS I SD NEGERI 011 BUKIT GAJAH KECAMATAN UKUI KABUPATEN PELALAWAN

2017 ◽  
Vol 5 (3) ◽  
pp. 451
Author(s):  
Ipi Hanapiati
Keyword(s):  
Learning Outcomes ◽  
Mathematics Learning ◽  
Learning Activities ◽  
Average Value ◽  
Study Results ◽  
Teachers And Students

This research was motivated by the low results of students' mathematics learning. Of the 35students only 15 students (40.54%) who completed study results, while the average valueobtained by the students was 68.65. This study aims to increase the students' mathematicslearning through PMRI. This research is a class act who performed two cycles. Based on theresearch of learning outcomes and learning activities teachers and students expressedincreased. In the first cycle 1 meeting activities for teachers to get a score of 14 (70%), in thefirst cycle 2 meeting increased with a score of 15 (75%). In the second cycle 1 meeting obtaina score of 17 (85%) and the second cycle 2 meeting obtain a score of 18 (90%). Besides thestudent activity also increased in the first cycle of meeting one activity students obtain a scoreof 12 (60%), in the first cycle 2 meeting increased with a score of 16 (80%). In the secondcycle 1 meeting obtain a score of 17 (85%) and the second cycle 2 meeting obtain a score of17 (85%). The results of students' mathematics learning increases the basic score averagevalue obtained was 68.65 increase in the first cycle with an average value of 95.41 hasincreased in the second cycle with an average value of 97.97.

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