• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.4
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• pp.403-408
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• 2014

If it were possible to control four sets of PMSMs in place of induction motors by using one inverter, we could attain efficient driving trains. In this paper, a method for controlling three sets of PMSMs with one inverter is shown. Additionally, this shows the method to control four sets of PMSMs with one inverter and the results of a simulation with the proposed method.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.6
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• pp.262-270
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• 2003

In this paper, the characteristics of single-phase line-start permanent magnet synchronous motor driven by constant voltage are analyzed on d-q axis vector diagram and compared with that of current controlled motor. The coupled method of symmetrical coordinates and d-q axis voltage equation are applied to the analysis method like the analysis of single-phase induction motor. From the result of the analysis, it is seen that motors driven by constant voltage source have effects on not only the amplitude of current and torque but also current and current phase angle, so overall characteristics such as power factor and load angle are affected by circuit parameters. For precise analysis and design of single-phase line-start synchronous motor, its characteristics should be analyzed on d-q axis vector plan in consideration of the variation of circuit parameters.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2107-2109
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• 1997

Speed sensors are required for the vector control of induction motors. These sensors reduce the sturdiness of the system and make it expensive. Therefore, a drive system without speed sensors is required. Also, the rotor inertia constant, the damping constant and the disturbed load torque of the IM are estimated by the RLS estimator and a torque observer. Then the observed disturbance torque is fed forward to increase the robustness of the IM speed drive.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.756-760
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• 2001

Two different designs of permanent magnet motors as direct wheel-set drive for the German high speed train ICE 3 are designed, one with surface mounted magnets (SM) and one with buried rotor magnets (BM). The surface magnet motor has $17\%$ less mass and a slightly higher efficiency and was therefore chosen for further investigations. Compared with the conventional drive system of the ICE 3, consisting of geared inverter fed induction machines, the gearless permanent magnet direct drive yields about $16\%$ lower losses. This calculation is based on the route parameters of the high speed track between Frankfurt/Main and Cologne in Germany, which is currently under construction.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.7 no.2
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• pp.57-63
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• 1993

In this paper, we study the effects that the variations of machine parameters and frequency of which affect the instability occured in induction motors when operated at low speed or light load, by obtaining the locus of dominant root for the characteristic equation.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.7 no.6
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• pp.51-59
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• 1993

In this paper, we study the effects that the variations of machine parameters and frequency of which affect the instability occured in induction motors when operated at low speed or light load, by obtaining the locus of dominant root for the characteristic equation.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.311-318
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• 2005

이 논문은 다른 종류의 유도전동기 구름베어링 손상을 유도전동기 고정자 전류신호해석을 통하여 검출하고 실시간으로 손상을 진단하는 알고리즘을 개발하였다. 유도전동기 구름베어링의 손상을 검출하기 위하여 정상적인 베어링을 갖는 유도전동기, 축정열에 불량을 가지고 있는 전동기와 베어링 외륜에 구멍을 가지고 있는 2가지 종류의 비정상 베어링을 갖는 유도전동기 3set를 실험시스템을 구축하였다. 또한 유도전동기의 구름베어링시스템의 비정상적인 상태에서 고정자전류을 검출하기 위하여 TMS320F2407 DSP 칩을 이용하여 데이터 획득보드를 개발하였다. 이 고정자전류신호를 해석을 통하여 베어링 손상을 검출하기 위한 방법으로 FPT, 웨이브렛 분석 및 내적에 의한 평균신호패던에 의한 분석결과를 제시하였다. 특히 내적에 의한 신호분석을 통하여 베어링 손상 여부를 실시간으로 진단할 수 있는 새로운 알고리즘과 분석방법을 제시하였다.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1196-1198
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• 1992

In field oriented control of Induction motors, speed sensor is required, which reduces the sturdiness of drive system and together with the expenditure of hardware for faultless transmission and processing of sensor signals it causes considerable expenses. These expensive sensors can be replaced by speed sensorless concept. And for good control, the knowledge of the rotor flux component of the rotor resistance are needs. Thus, this paper is based on a Extended Kalman Filter( EKF ) that estimates the state variables that are required for the control by only measuring the line voltages and currents of the machine. The rotor time constant and speed estimated by the EKF shows satisfactory agreement with the real values, with the simulation approaches.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.93_94
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• 2009

Load modeling has a significant impact on power system analysis and control. Estimating model parameters can be considered as important as stability analysis itself for accurate analysis and control. This paper presents a method for estimating parameters for load models, which include static and dynamic parts, based on particle swarm optimization. The method effectively searches a suitable set of parameters minimizing the fitness function. This paper applies the method to simulation data obtained from 8-bus test system including induction motors.

• Journal of Electrical Engineering and Technology
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• v.8 no.5
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• pp.1062-1069
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• 2013

This paper proposes a simple current compensation method to improve the control performance of B4 inverters. Four-switch inverters so called B4 inverters employ only four switches. They have a split dc-link and one phase of three-phase motors is connected to the center-tap of split dc-link capacitors in B4 inverters. The voltage ripples in the center tap of the dc-link generate unbalanced three-phase voltages causing current ripples. To solve this problem, this paper presents a simple compensation method that adjusts switching times considering dc-link voltage ripples. The validity of the proposed method is verified by simulations and experiments carried out with a 1 HP induction machine.