• Title/Summary/Keyword: motors

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Evaluation of Winding Insulation of IGBT PWM Inverter-Fed Low-Voltage Induction Motors

  • Park Doh-Young;Hwang Don-Ha;Kim Yong-Joo;Kang Do-Hyun;Lee Young-Hoon;Kim Dong-Hee;Lee In-Woo
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.470-474
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    • 2001
  • IGBT inverters have switching rise times of 0.2-2 $\mu$ sec, and have been believed to cause insulation stresses and premature motor failures. Inverter driven induction motors with high speed switching and advanced PWM techniques are widely used for variable speed applications. Recently, the insulation failures of stator winding have attracted many concerns due to high dv/dt of IGBT PWM inverter output. In this paper, the detailed insulation test results of 19 low-voltage induction motors are presented. Different types of insulation techniques are applied to 19 motors. The insulation characteristics are analyzed with partial discharge, discharge inception voltage, and dissipation factor tests. Also, breakdown tests by high voltage pulses are performed, and the corresponding breakdown voltages are obtained.

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Parallel Sensorless Speed Control using Power Angle for Dual SPMSMs Fed by a Single Inverter (단일 인버터 기반 두 대의 영구자석 동기전동기 병렬운전에서 전력각을 이용한 속도제어기법)

  • Kim, Kyung-Hoon;Yun, Chul;Kwon, Woo-Hyen
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.10
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    • pp.1481-1487
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    • 2017
  • This paper proposes a sensorless speed control algorithm for parallel-connected dual Surface-mounted Permanent Magnet Synchronous Motors fed by a single inverter. For stable parallel operation of synchronous motors with a single inverter, each motor has to be constantly kept in the synchronization state regardless of load torque. If the master motor with the larger load is controlled, the synchronous state will be maintained. Therefore, detection of the master motor is essential. Conventionally, the master motor is determined by comparing the rotor position error from the relation between the back-EMF for torque angle and the flux position. consequently, the position sensor is deemed essential for finding the rotor position. In this paper, we proposed a method that decides the magnitude of the load from the power angle of two motors due to the load variation and selects the motor to control through the sign function for the sensorless speed control without the position sensor. The results of simulation and experiment conducted verify the efficacy of the proposed method.

Imbedded Type Real-Time Fault Diagnosis for BLDC Motors (임베디드 타입의 실시간 BLDC 전동기 고장진단 시스템 구현)

  • Park, Jin-Il;Kim, Yong-Min;Lee, Dae-Jong;Cho, Jae-Hoon;Chun, Myung-Geun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.4
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    • pp.62-71
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    • 2009
  • In this paper, we propose a fault diagnosis algorithm for BLDC motors by principle component analysis (PCA) and implement a real-time fault diagnosis system for BLDC motors. To verify the proposed diagnosis algorithm, various faulty data are acquired by Lab VIEW program from experimental system. We extract a fault feature using principle component analysis after preprocessing and then finally the fault diagnosis is performed by Euclidean similarity. Also, we embed the PCA algorithm and k-NN classification algorithm into a digital signal processor. From various experiments, we found that the proposed algorithm can be used as a powerful technique to classify the several fault signals acquired from BLDC motors.

Copper Loss and Torque Ripple Minimization in Switched Reluctance Motors Considering Nonlinear and Magnetic Saturation Effects

  • Dowlatshahi, Milad;Saghaiannejad, Sayed Morteza;Ahn, Jin-Woo;Moallem, Mehdi
    • Journal of Power Electronics
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    • v.14 no.2
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    • pp.351-361
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    • 2014
  • The discrete torque generation mechanism and inherently nonlinear magnetic characterization of switched reluctance motors lead to unacceptable torque ripples and limit the application of these motors. In this study, a phase current profiling technique and torque sharing function are proposed in consideration of magnetic saturation effects and by minimizing power loss in the commutation area between the adjacent phases. Constant torque trajectories are considered in incoming and outgoing phase current planes based on nonlinear T-i-theta curves obtained from experimental measurements. Optimum points on constant torque trajectories are selected by improving drive efficiency and minimizing copper loss in each rotor position. A novel analytic invertible function is introduced to express phase torque based on rotor position and its corresponding phase current. The optimization problem is solved by the proposed torque function, and optimum torque sharing functions are derived. A modification method is also introduced to enhance the torque ripple-free region based on simple logic rules. Compared with conventional torque sharing functions, the resultant reference current from the proposed method has less peak and effective values and exhibits lower copper loss. Experimental and simulation results from a four-phase 4 KW 8/6 SRM validate the effectiveness of the proposed method.

A Study on the International Standard and Regulation for Electric Motor and Drives (전동기와 드라이브의 국제 규격 및 규제에 관한 현황 연구)

  • Woo, Kyung-Il;Park, Han-Seok;Kim, Dea-Kyong;Choi, Han-Seok;Jun, Hee-Deuk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.3
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    • pp.437-443
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    • 2014
  • Electric motors and drives consume the largest amount of electricity more than 40% of global electricity consumption. In addition, motors, drives and its components are included in the global high-trade products and the main driving source for industrial equipment and house appliances. Thus, International standards and regulations for their safety and efficiency are internationally being discussed and created for the protection of its citizens and energy saving. So, understanding the international standards and the regulation of each country is essential to enhance overseas market and to develop product. In this paper, on the basis of this background, status and trends of international standards and regulations are introduced for safety and efficiency of motors and the drives. Safety and efficiency of the IEC (International Electrotechical Commission) standards are introduced in the emphasis. Also, regulations are studied about the differences and trends in each county.

Performance Loss & Heat Transfer Characteristics of Synchronous Motors under Various Driving Conditions (구동 조건 변화에 따른 동기 전동기의 성능 손실 및 내부 열전달 특성)

  • Choi, Moon Suk;Um, Sukkee
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.3
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    • pp.165-173
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    • 2013
  • Core loss has a major effect on heat generation in synchronous motors with surface-mounted permanent magnets (SPMs). It is essential to perform heat transfer analysis considering core loss in SPM because core loss is seriously affected by torque and speed of motors. In the present study, mechanical loss, core loss and coil loss are evaluated by measuring input and output energies under various driving conditions. For a better understanding heat transfer paths in synchronous motors, we developed a lumped thermal system analysis model. Subsequently, heat transfer analysis has been performed based on acquired energy loss, temperature data and thermal resistance with three types of SPM. It is shown that the torque constants decrease by Max. 10% as speed increase. At the rated torque, the core loss is Max. 10.9 times greater than the coil loss and the hysteresis loss of magnets is dominant in total loss.

Analysis of Rotor Vibration Types Caused by Air-gap Flux Variations in Induction Motors (유도전동기 공극자속 변화에 따른 진동유형 해석)

  • Hwang Don-Ha;Lee Ki-Chang;Lee Joo-Hoon;Kim Yong-Joo;Choi Kyeong-Ho;Lee Jin-Hee
    • Proceedings of the KIPE Conference
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    • 2004.07b
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    • pp.862-865
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    • 2004
  • Faults such as broken rotor bars, static and dynamic eccentricity are often reported in induction motors. These faults increase the down-time of equipment, which causes major loss of earnings to the industry. This paper presents a result of the finite-element(FE) analysis of air-gap flux variation in induction motors when rotor vibration conditions occur, An accurate modelling and analysis of rotor vibration in the machine are developed using FE software packages, and measuring the flux are made using the search coils. In the FE analysis, an induction motor with 380 [V], 5[HP], 4 Poles, 1742 [rpm] ratings is used. The results of FE analysis can be used for on-line vibration monitoring of the induction motors.

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Data Structure for the Design Program of Solid Rocket Motors (고체 추진기관 구조체 설계 프로그램 개발을 위한 설계 부품 자료 구조)

  • Lee, Kang-Soo;Kim, Won-Hoon;Lee, Bang-Eop
    • Korean Journal of Computational Design and Engineering
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    • v.17 no.5
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    • pp.364-374
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    • 2012
  • In this paper, we proposed a data structure to represent structural components of solid rocket motors (SRM) in an automated design program. To propose the data structure, we searched the necessary functions for the automated design program should have. In order to design the structural components of solid rocket motors sufficiently with a design program, it should have the functions to represent the shapes of the components, the drawing and analysis models, the design variables, various product structures, interferences, characteristic properties, design equations, and tightening sets. By modifying the data structure of an element object that is a general purpose data structure to represent a general component of a product, a new data structure was proposed to satisfy all the necessary functions with optimum. Finally, a design program for the structural components of solid rocket motors was developed successfully with the proposed data structure.

The Current State of D-lactic Acid Production Technology Using Microorganism (미생물을 이용한 D형 유산 생산 기술 현황)

  • Hong, Chae-Hwan;Kim, Si-Hwan;Seo, Ji-Yeon;Han, Do-Suck;Kim, Yong-Hwan
    • KSBB Journal
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    • v.26 no.6
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    • pp.477-482
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    • 2011
  • There has been a growing attention on PDLA (poly D-lactic acid) since stereocomplex PLA, a kind of polymer alloy between PLLA and PDLA was known much thermally stable compared PLLA. Superior characteristics of stereocomplex PLA result in the elevated demand for D-lactic acid. Although many research works have been reported for L-lactic acid production especially food industry, however there are relatively few research works for D-lactic acid production since D-lactic acid cannot find any applications in food industry. Most imminent issue for D-lactic acid is the economic production process that requires low cost medium, efficient lactic acid producing microorganism and finally large scale-up design. In this review, current status of D-lactic acid production process will be summarized and discussed for the further improvement of D-lactic acid production process.

A Study on the Polarity Discrimination Method of the Stator Windings for 3 Phase Induction Motors based on the Residual Magnetism and I Winding Connection (잔류자기와 I 결선에 의한 3상유도전동기 고정자 권선의 극성판별법에 대한 연구)

  • Choi, Soon-Man
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.1
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    • pp.72-77
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    • 2015
  • When connecting 6 lead wires from stator windings to the terminals of 3 phase induction motors for Y or ${\triangle}$ connection, it is feared that the polarities of windings could be reversed each other if the wire tags are lost or erased, resulting in inadmissibly high current to motors in case of starting. To protect motors against such situations, some test procedures are necessary during wire connection which need to be easy ways to electricians without particular tools except a general multi-tester and with less time-consuming in the field. This study focuses on a test measure to satisfy these requirements which is able to provide them a convenient procedure for winding polarity discrimination considering the field condition. Here, the proposed measure utilizes the residual magnetism of the rotor and checks the indication of voltage or current at windings which are induced by the residual flux of rotor when rotating it by hands with 3 stator windings connected in the form of I connection. Principle characteristics and experiment results for this method are analyzed in the view of the effectiveness and applicability for the winding polarity discrimination.