• 조명전기설비학회논문지
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• 제20권10호
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• pp.82-93
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• 2006

본 논문에서는 인버터 구동 고압유도전동기 운전시 스위칭 서지로 인하여 고압유도 전동기 단자에서 발생하는 과도과전압을 저감하기 위한 필터로 인버터 출력단자에서 dv/dt를 저감하는 LCR 필터와 전동기 입력단자에서 케이블과 유도전동기 특성임피던스를 매칭시키는 RC필터에 대한 과도과전압 저감특성을 분석하였다. 이 필터를 고압에 대용량 유도전동기에 적합하도록 EMTP(ElectroMagnetic Transients Program)를 이용하여 모델링 및 케이블 영향에 의한 필터의 과도과전압 저감효과를 전압파형과 고조파 스펙트럼으로 비교분석하고, 이를 토대로 고압 대용량 유도전동기에 사용될 필터를 제시하였다. 인버터 스위칭 서지에 의한 과도과전압은 유도전동기 고정자 권선에 심각한 전압 스트레스를 발생시켜 절연파괴를 일으키는 주요원인이 된다. 이러한 과도과전압을 저감위한 필터설계는 고압유도전동기 시스템에서 필수적인 요소임을 보였다. 또한 제시된 필터는 과도과전압을 효과적으로 저감시키는 것을 EMTP 시뮬레이션을 통하여 입증하였다.

• 전기의세계
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• 제26권5호
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• pp.65-73
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• 1977

This paper work treats with the basic characteristics to be investigated in development of a single-phase linear induction motor. The results of this research work have established some important characteristics which should be taken into consideration in the design and construction of this linear motor, And it is also proven that the development of high-voltage linear machine with large capacity is possible.

• 한국산학기술학회논문지
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• 제8권4호
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• pp.748-757
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• 2007

본 논문은 대용량 유도전동기가 기동할 때 발생하는 큰 돌입전류로 인해 PCC(Point of Common Coupling)에 심한 전압 강하가 발생하게 되어 기동에 실패하는 문제를 해결하기 위해 대상 유도전동기의 기동 특성과 배전계통을 모델링하고 시뮬레이션을 수행함으로써 유도기 기동시에 전압저하 현상을 해석하였다. 문제가 되는 유도전동기는 2500KVA 용량의 펌프용 농형 유도전동기로 리액터 기동법을 채용하고 있다. 2500KVA 유도전동기 한대의 기동에는 문제가 없으나 기동 완료 후 PCC 전압이 다소 떨어진다. 하지만 추가로 동일 용량의 유도전동기가 기동하게 되면 PCC의 심한 전압강하로 기동에 실패하게 되는 문제가 발생하였다. 이러한 문제 해결을 위해 본 논문에서는 실제 기기의 기동시 토크-속도 곡선을 이용한 유도전동기의 기동 특성을 정확히 모델링하고 시뮬레이션을 수행하여 두 대의 대용량 유도전동기가 순차적으로 기동에 성공할 수 있는 적절한 전압보상 방안을 제안하였다. 본 논문에서 논의되는 대용량 유도전동기는 한국수자원공사의 취수장에서 운전되고 있으며 대상 유도전동기 및 배전계통은 PSCAD/EMTDC 소프트웨어를 사용하여 모델링 및 시뮬레이션을 수행하였다.

• 전기학회논문지P
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• 제67권3호
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• pp.155-159
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• 2018

Recently, the expansion or establishment of facilities for the logistics system is increasing. Conveyor facilities play a major role in sorting and transporting logistics. Induction motors are widely used for the operation of these conveyor systems. In the logistics system, a large number of induction motors are used. These motors have a considerable distance from the power source side and have a low power factor. The installation position for the power factor compensation of the induction motor is very important. Since the voltage drop depends on the length of the line, it is an important parameter in capacitor capacity determination for power factor compensation. The capacity of the capacitors installed to compensate the power factor of the inductive load should be designed to the extent that self-excitation does not occur. In this study, we analyze the method of compensating the proper power factor considering the voltage drop and the installation position of the induction motor in the logistics system.

• 신재생에너지
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• 제10권4호
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• pp.3-8
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• 2014

Both of induction generator and synchronous generator is available in the hydroelectric power plant. If the output of the power station is large, the synchronous generator is mainly used but when its output is low, the induction generator is often used. If the output capacity is small, there is a case in which induction motor is used as a generator. Torque at rated operation and start of the induction motor is different depending on the shape of the rotor. Small and medium-sized squirrel-cage induction motor is used primarily double cage rotor or deep bar. In this study, we attempt to interpret characteristics for double cage rotor or deep bar that occur when operating in the induction generator based on the parameters that have been designed and manufactured as an induction motor.

• 전기학회논문지P
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• 제63권1호
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• pp.24-28
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• 2014

An induction motor is most widely used to obtain driving force in the industrial field. The induction motor is generated a high current at starting. A starting current is often more than five times of rated current. A high starting current can cause problems such as voltage drop in the power system. In order to solve these problems, a reactor starting method has been widely applied in a large motor capacity. There are differences in the operating characteristics of induction motor corresponding the switching time of reactor tap. In this study, I analyzed that current, torque, power of induction motor are different from changing time and tap setting values of reactor tap.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.202-203
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• 2007

Induction Motor is important at tilting train. Tiling train induction motor should be operated to commercial servicespeed 180km/h at Korea Conventional Line upgrade railroad. As the induction motors are without commutators, maintenance is easy and it is far lighter than the conventional motors with the same capacity. The induction motor, however, posed problems in use as its motor torque is not large enough compared with DC motors. With the recent advances in power semiconductors, it is possible to apply the induction motors to trains by applying VVVF inverter control method to the traction motor. In this study, we realize the stable measurement AC motor temperature characteristic of TTX train.

• 조명전기설비학회논문지
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• 제26권8호
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• pp.65-70
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• 2012

Induction motor is the most widely used to obtain the driving force in the industrial site. Induction motor generates a high current at startup. Most of starting currents are often more than five times of rated current. This high starting current can cause problems such as the voltage drop in the system. In order to solve these problems, if the motor capacity is large, generally we use reactor starting method rather than direct on line starting method. When a high startup current passes through reactor, reactor can serve as a nonlinear elements. In this study, we analyzed that the current, torque and power of the induction motor are different from the change of linear and nonlinear components of the reactor magnetic field.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권9호
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• pp.442-447
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• 2003

Motors with HTS wires or bulks have been developing recently. Those are large synchronous motor with HTS wires at the field winding in the rotor, hysteresis and reluctance motors with HTS bulk in the rotor. This paper presents the fabrication and test results of an HTS induction motor. Conventional end rings and short bars were replaced with HTS wires in the motor. Stator of the conventional induction motor was used as the stator of the HTS motor. Rated capacity and rpm at full rotor of the conventional motor were 0.75[kW] and 1,710[rpm]. Two, HTS wires are used in parallel to make the end rings and bars. The critical current of the BSCCO-2223 HTS wire which was used in the bars and end rings were 115[A]. Electrodynamometer was coupled directly to the shaft of the rotor with HTS wires.

• 한국초전도ㆍ저온공학회논문지
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• 제6권3호
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• pp.33-37
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• 2004

This paper presents the construction and test results of an HTS induction motor. End rings and short bars were made of HTS tapes, To increase the efficiency and starting torque, HTS tapes can be used as the rotor bars. Because large current is induced in the rotor circuit, HTS tapes quench and high starting torque can be obtained. As the speed of rotor builds up. HTS tapes which are used as short bars become superconducting state again. After the HTS tapes recover from quench, resistance of the rotor circuit is nearly zero. In that case, power loss in rotor circuit is eliminated. Stator of the conventional induction motor was used as the stator of the HTS motor. Rated capacity of the conventional motor was 0.75 kW. Performances of the HTS induction motor were compared with those of the conventional motor with same volume and specification. Test result showed that the speeds of the HTS induction motor were the same with synchronous speed up to 2.6 Nm and 1.788 rpm at 9.7 Nm. It guarantees the high efficiency of the HTS motor. Starting torque of the HTS motor was more than twice of the conventional motor.