• Title/Summary/Keyword: motors

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Characteristic of Current and Temperature according to Normal and Abnormal Operations at Induction Motor of 2.2 kW and 3.7 kW (2.2 kW와 3.7 kW 유도전동기의 정상과 구속운전에 따른 전류 및 온도 특성)

  • Jong-Chan Lee;Doo-Hyun Kim;Sung-Chul Kim
    • Journal of the Korean Society of Safety
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    • v.38 no.3
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    • pp.35-42
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    • 2023
  • This study analyzed the current and temperature characteristics of major components of an induction motor during normal and abnormal operations as functions of the difference in the rated capacities of medium and large-sized motors widely used in industrial settings. The temperature rise equation of the induction motor winding was derived through locked-rotor operation experiments and linear regression analysis. When the ambient temperature is 40 ℃, the time to reach 155 ℃, the temperature limit of the insulation class (F class) of the winding of the induction motor, was confirmed to be 48 seconds for the 2.2 kW induction motor and 39 seconds for the 3.7 kW induction motor. This means that when the rated capacity is large or the installation environment is high temperature, the time to reach the temperature limit of the insulation class during locked-rotor operation is short, and the risk of insulation deterioration and fire is high. In addition, even if the EOCR (Electronic Over Current Relay) is installed, if the setting time is excessively set, the EOCR does not operate even if the normal and locked-rotor operation of the induction motor is repeated, and the temperature limit of the insulation grade of the winding of the induction motor is exceeded. The results of this study can be used for preventive measures such as the promotion of electrical and mechanical measures for the failure of induction motors and fire prevention in industrial sites, or the installation of fire alarm systems.

Development of Servo for Small Tracking Radars (소형 추적 레이다용 서보 개발)

  • Lee, Jong-Kuk;Lee, Seok-In;Kim, Jun-Su;Song, Tae-Seong;Eom, Young-Cheol;Ahn, Se-Hwan;Shin, Yu-Jin;Joo, Ji-han;Kwon, Jun-Beom;Kim, Sang-Wook
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.22 no.6
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    • pp.21-30
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    • 2022
  • This paper describes the design, manufacture, and testing of servos applicable to small tracking radars. First, Chapter 1 describes the necessity of this study. Chapter 2 describes the development of servos applicable to future tracking radars in small missile systems. Chapter 3 describes the design and test results for current control of brushed DC motors, brushless DC motors, and permanent magnet synchronous motors. And Chapter 4 describes the design and test results for speed control of the test wheel. And in Chapter 5, the results of the previous tests are summarized. In this paper, some pictures were intentionally blurred for security reasons, and the control result of test wheel was described, not the test with the developed gimbals.

A Case Study on Quality Improvement of Electric Vehicle Hairpin Winding Motor Using Deep Learning AI Solution (딥러닝 AI 솔루션을 활용한 전기자동차 헤어핀 권선 모터의 용접 품질향상에 관한 사례연구)

  • Lee, Seungzoon;Sim, Jinsup;Choi, Jeongil
    • Journal of Korean Society for Quality Management
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    • v.51 no.2
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    • pp.283-296
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    • 2023
  • Purpose: The purpose of this study is to actually implement and verify whether welding defects can be detected in real time by utilizing deep learning AI solutions in the welding process of electric vehicle hairpin winding motors. Methods: AI's function and technological elements using synthetic neural network were applied to existing electric vehicle hairpin winding motor laser welding process by making special hardware for detecting electric vehicle hairpin motor laser welding defect. Results: As a result of the test applied to the welding process of the electric vehicle hairpin winding motor, it was confirmed that defects in the welding part were detected in real time. The accuracy of detection of welds was achieved at 0.99 based on mAP@95, and the accuracy of detection of defective parts was 1.18 based on FB-Score 1.5, which fell short of the target, so it will be supplemented by introducing additional lighting and camera settings and enhancement techniques in the future. Conclusion: This study is significant in that it improves the welding quality of hairpin winding motors of electric vehicles by applying domestic artificial intelligence solutions to laser welding operations of hairpin winding motors of electric vehicles. Defects of a manufacturing line can be corrected immediately through automatic welding inspection after laser welding of an electric vehicle hairpin winding motor, thus reducing waste throughput caused by welding failure in the final stage, reducing input costs and increasing product production.

Diagnosis of Inter Turn Short Circuit in 3-Phase Induction Motors Using Applied Clarke Transformation (Clarke 변환을 응용한 3상 유도전동기의 Inter Turn Short Circuit 진단)

  • Yeong-Jin Goh;Kyoung-Min Kim
    • Journal of IKEEE
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    • v.27 no.4
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    • pp.518-523
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    • 2023
  • The diagnosis of Inter Turn Short Circuits (ITSC) in induction motors is critical due to the escalating severity of faults resulting from even minor disruptions in the stator windings. However, diagnosing ITSC presents significant challenges due to similarities in noise and losses shared with 3-phase induction motors. Although artificial intelligence techniques have been explored for efficient diagnosis, practical applications heavily rely on model-based methods, necessitating further research to enhance diagnostic performance. This study proposed a diagnostic method applied the Clarke Transformation approach, focusing solely on current components while disregarding changes in rotating flux. Experimental results conducted over a 30-minute period, encompassing both normal and ITSC conditions, demonstrate the effectiveness of the proposed approach, with FAR(False Accept Rates) of 0.2% for normal-to-ITSC FRR(False Rejection Rates) and 0.26% for ITSC-to-normal FRR. These findings underscore the efficacy of the proposed approach.

A Study on Improvement in Quality System Evaluation for Production Approval of Aircraft and Parts (항공기 및 부품 생산승인을 위한 품질시스템 평가기준 개선 연구)

  • Kang-Yi Lee;Jae-Hoon Han;Jung-Sam Lee
    • Journal of Aerospace System Engineering
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    • v.17 no.6
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    • pp.118-126
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    • 2023
  • Most of the aerospace industries establish the SAE AS9100 Quality Management System, and acquire commercial certification by the 3rd party. Nevertheless, they repeatably have to cope with similar quality system evaluation by the airworthiness authority for the production certificate, parts manufacturer approval, and technical standard order authorization in accordance with the applicable regulations. The current quality system evaluation criteria of the airworthiness authority could be recommended for reforms in order to reduce duplication and correspond to the industrial development and environmental changes. In this paper, we propose measures to reform the authority's evaluation criteria through comparative analysis among the IAQG SAE AS9100, the FAA quality system codes, and the MOLIT ACSEP requirements.

Field Loss Analysis and Cooling Analysis of HTS Synchronous Motor (고온초전도 동기모터의 계자손실 해석 및 냉각 해석)

  • Kim, Ki-Chan;Lee, Dae-Dong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.3
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    • pp.69-74
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    • 2018
  • Large industrial motors require a large area because of the high risk of shutdown accidents and large industrial accidents due to the lowering of the dielectric strength of the armature windings and overheating problems. Therefore, there is a demand for a large-capacity motor that has small size, light weight, and excellent dielectric strength compared with conventional motors. Superconducting motors have advantages of high efficiency and output power, low size, low weight, and improved stability. This results from greatly increasing the magnetic field generation by using superconductive field coils in rotating machines such as generators and motors. It is very important to design and analyze the cooling system to lower the critical temperature of the wires to achieve superconducting performance. In this study, a field loss analysis and low-temperature heat transfer analysis of the cooling system were performed through the conceptual design of a 100-HP high-temperature superconducting synchronous motor. The field loss analysis shows that a uniform pore magnetic flux density appears when high-temperature superconducting wire is used. The low-temperature heat transfer analysis for gaseous neon and liquid neon showed that a flow rate of 1 kg/min of liquid neon is suitable for maintaining low-temperature stability of the high-temperature superconducting wire.

Study on Development of Wheelchair Transfer-Storage Mechanism for Car (차량용 휠체어 이송수납메커니즘의 개발에 관한 연구)

  • Lim, Gu;Kim, Yong Seok;Le, QuangHoan;Jeang, Young Man;Oh, Dong Kwan;Oh, Ji Woo;Yea, Chan Ho;Yang, Soon Yong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.10
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    • pp.1109-1116
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    • 2014
  • The wheelchair mechanism for a car that is proposed in this study primarily consists of a transfer mechanism and storage mechanism. The wheelchair transfer mechanism consists of a manipulator installed in the roof of a car, and performs the function of transferring the wheelchair from the driver's seat to the trunk. The wheelchair storage mechanism consists of a lifting hoist installed in the trunk of car, and performs the function of storing the transferred wheelchair in the trunk and safely fastening it in place. This study analyzed and reviewed various manipulators, including a vertical type, Scara type, and telescopic type, with the goal of selecting the best type of manipulator for the wheelchair transfer mechanism. The telescopic type was selected and applied because of its good load support and storage capabilities. In addition, with regard to the wheelchair storage mechanism, a slide hoist type that used a slide rail and lift wire and a rotating link hoist type that used a rotating mechanism consisting of a worm gear and link were analyzed and reviewed. The slide hoist type was selected and applied because it had an advantage in relation to trunk space utilization. This study proposed a wheelchair transfer mechanism for a car to support a conventional wheelchair user's movements, and in order to conform to the structure of a domestic welfare car for the disabled.

Developing an improved water discharge anchor & trap bolt to prevent basic salt penetration to harbor structures (해수 염기 침투방지를 위한 성능개선 형 물배출 앵커 및 트랩볼트 개발에 관한 연구)

  • Ock, Jong-Ho;Moon, Sang-Deok;Lee, Hwa-Sun;Shin, Kyung-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.4
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    • pp.674-682
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    • 2018
  • Large industrial motors require a large area because of the high risk of shutdown accidents and large industrial accidents due to the lowering of the dielectric strength of the armature windings and overheating problems. Therefore, there is a demand for a large-capacity motor that has small size, light weight, and excellent dielectric strength compared with conventional motors. Superconducting motors have advantages of high efficiency and output power, low size, low weight, and improved stability. This results from greatly increasing the magnetic field generation by using superconductive field coils in rotating machines such as generators and motors. It is very important to design and analyze the cooling system to lower the critical temperature of the wires to achieve superconducting performance. In this study, a field loss analysis and low-temperature heat transfer analysis of the cooling system were performed through the conceptual design of a 100-HP high-temperature superconducting synchronous motor. The field loss analysis shows that a uniform pore magnetic flux density appears when high-temperature superconducting wire is used. The low-temperature heat transfer analysis for gaseous neon and liquid neon showed that a flow rate of 1 kg/min of liquid neon is suitable for maintaining low-temperature stability of the high-temperature superconducting wire.

Trend in Research and Development Related to Motors and Permanent Magnets for Solving Rare-earth Resources Problem (희토류 자원문제 해결을 위한 모터 및 영구자석 연구개발 동향)

  • Lee, J.G.;Yu, J.H.;Kim, H.J.;Jang, T.S.
    • Journal of the Korean Magnetics Society
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    • v.22 no.2
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    • pp.58-65
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    • 2012
  • Since Nd-Fe-B magnet was first synthesized in 1983, many new applications have emerged in the past two decades. With regard to motor market, it will expand because of strong energy saving requirements from the automobile and electric application markets. Especially, permanent magnet motors for hybrid and electric vehicles are drawing great attention and the usage of Nd-Fe-B magnets will increase all the more hereafter. There is, however, a serious problem as motors in such eco-friendly cars are said to operate in high temperatures of about $200^{\circ}C$. Nd-Fe-B magnet has a drawback of dramatically decreasing coercive force with the rise of temperature. In order to improve this aspect. the best way is to add dysprosium (Dy) into the magnet. So, Dy has become an essential element for Nd-Fe-B high-performance magnet as it helps to maintain coercive force even at high temperatures. On the other hand, the rare earth resources in the earth crust are eccentrically-located and its majority is produced in China. There is a need to reduce its usage as, especially compared to light rare earth elements as neodymium (Nd) and samarium (Sm), heavy rare earth elements including Dy are unevenly distributed to a dramatic degree, their output low, and their prices are about 10 times that of Nd. The present article includes a summary of the trend in research and development of motors and permanent magnets to solve rare-earth resources problem.

The Design of Long-Stator Linear Motor Drives for RailCab Test Track

  • Grotstollen Horst
    • Journal of Power Electronics
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    • v.5 no.2
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    • pp.166-172
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    • 2005
  • The basic equations of a doubly-fed long-stator linear motor for a shuttle-based railway system are established. They show which degrees of freedom exist for controlling the motor. The ratio of stator and rotor current proves to be an important parameter in determining the design of motors, converters and mechanics.