• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.1
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• pp.41-45
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• 2008

This paper deals with the estimation method on the initial pole position of a z-axis permanent magnet linear synchronous motor(PMLSM) without magnetic pole sensors such as Hall sensors. The proposed method takes account of the gravitational force at z-axis and also the load conditions. The algorithm consists of two steps. The first step is to approximately estimate the initial q-axis by monitoring the movements due to the test current at predefined different test q-axes. The second step is to estimate the real q-axis as accurately as possible by using the outputs corresponding to torques due to the test current at three different test q-axes in order to avoid the effect of load mass variations. Experimental results on the z-axis PMLSM show good estimation characteristics of the proposed method irrespective of load mass conditions.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.4
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• pp.273-278
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• 2019

This study proposes a method for improving the overmodulation performance of a three-phase inverter to obtain an enhanced output torque for the AC motors. In the inverter-fed AC motor drives, the output torque of the motor can be enhanced by utilizing the overmodulation region as well as the linear modulation regions of the inverter. The overmodulation method is used for this overmodulation operation of the inverter. However, the voltage gain, the ratio of the output voltage of the inverter to the reference voltage achieved by the conventional overmodulation methods becomes nonlinearly smaller than unity. Therefore, the effect of improving the output torque of the AC motors is insignificant even when the overmodulation region is utilized. In this study, we propose a method that improves the overmodulation performance of the inverter by compensating the limited amount of the reference voltage in the overmodulation operation to enhance the output torque of the AC motors. The effectiveness of the proposed method is verified through the simulations and experiments with an 800 W permanent magnet synchronous motor.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.4
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• pp.973-983
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• 2015

To improve the control performance of the IPMSM, a novel nonlinear disturbance observer is proposed by using the T-S fuzzy model. A T-S fuzzy model is the combination of local linear models considered at each operating point. Usually the inverse model is easy to obtain in linear systems but not in nonlinear systems. To design a nonlinear disturbance observer, a nonlinear inverse model is obtained based on nonlinear inverse model which is the fuzzy combination of the local linear inverse models. The proposed DOB is used with a PDC controller which is one of the T-S fuzzy controller, and its performance improvement is shown from the simulation results.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.169-170
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• 2013

본 논문에서는 장거리 운송 시스템의 정밀 제어에 적합한 영구자석 선형 동기전동기의 추진 제어 방법을 제안하고자 한다. 적용 시스템은 코일이 고정되어 있고 영구자석이 이동자를 구성하는 형태로서 빠른 응답특성을 위해 아날로그 형태의 전류제어기를 사용하였고, 섹션 전환을 통해 추진제어가 이루어진다. 제안한 추진 제어방법을 적용한 영구자석 선형 동기전동기의 구동에 대한 시뮬레이션을 통하여 제안한 방법의 구현 가능성을 검증하였다.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.137-139
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• 2006

단 1차형 영구자석 선형 동기 전통기(PMLSM)는 디텐트력과 단부력에 의한 큰 토크 리플을 갖는 문제점이 있다. 본 논문에서는 영구자석 선형 통기 전동기의 디텐트력을 줄이기 위해 영구자석의 극수와 전기자의 슬롯수의 비를 변경한 새로운 구조의 단 1차형 영구자석 선형 동기 전동기를 제안하였으며, 단부력을 줄이기 위하며 고정자의 길이 조정 및 챔퍼링을 통하여 영구자석 선형 동기 전동기를 설계하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.12
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• pp.71-77
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• 2010

A discontinuity of magnetic circuits according to the end effect is generated in PMLSM. And magnetic state of the 3 phase coils becomes unbalanced. Due to the unbalanced magnetic state, the unbalanced flux linkage, back electro-magnetic force and inductance of the 3 phase coils appear. In result, the circulating current is generated by unbalanced inductance even if the input voltages are in balanced state. Then the thrust and efficiency are decreased because of the circulating current. Therefore, in this paper, the unbalanced inductance and the thrust reduction according to discontinuity of magnetic circuits are analyzed by FEA(2D). To demonstrate the validity of the analysis results, the experiment results are compared with analysis results.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.620-623
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• 2000

A very simple control approach using neural network for the robust position control of a Permanent Magnet Synchronous Motor(PMSM) is presented The linear quadratic controller plus feedforward neural network is employed to obtain the robust PMSM system approximately linearized using field-orientation method for an AC servo. The neural network is trained in on-line phases and this neural network is composed by a fedforward recall and error back-propagation training. Since the total number of nodes are only eight this system can be easily realized by the general microprocessor. During the normal operation the input-output response is sampled and the weighting value is trained multi-times by error back-propagation method at each sample period to accommodate the possible variations in the parameters or load torque. And the state space analysis is performed to obtain the state feedback gains systematically. IN addition the robustness is also obtained without affecting overall system response. This method is realized by a floating-point Digital Singal Processor DS1102 Board (TMS320C31) The basic DSP software is used to write C program which is compiled by using ANSI-C style function prototypes.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.812_813
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• 2009

본 논문에서 로프리스 엘리베이터용 영구자석형(PM) 선형동기전동기(LSM)의 디텐트력을 저감하기 위하여 반응표면법(RSM)을 이용한 디텐트력의 최소화 설계 방법을 제안하였다. RSM을 이용하여 정수 슬롯형과 분수 슬롯형 PM-LSM의 설계변수를 추론하고 유한요소법(FEM)으로 디텐트력을 구하였다. 반응표면법과 유한요소법의 해석결과를 토대로 분수 슬롯형 PM-LSM이 주어진 체적의 엘리베이터 시스템에 적합한 형상임을 입증한다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.10
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• pp.1767-1776
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• 2008

This paper presents the status of advanced technologies and domestic researches for development of Korean next generation maglev. Generally, two specific configurations such as the EMS (Electromagnetic Suspension) with LSM (Linear Synchronous Motor) and EDS (Electrodynamic Suspension) with LSM can be employed as a propulsion and levitation device of high-speed maglev. Worldwide high-speed maglev developments refer to projects such as the German Transrapid with EMS, the Japanese MLX with EDS, and the U.S. Inductrack with PM (Permanent Magnet) EDS maglev system. In this paper, the propulsion and levitation systems of these world wide high-speed maglev have been reviewed and analysed.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.165-167
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• 2007

영구자석 선형 동기 전동기(PMLSM)는 코깅력과 단부력에 의한 큰 추력 리플을 갖는 문제점이 있다. 본 논문에서는 영구자석 선형 동기 전동기의 디텐트력을 줄이기 위해 영구자석의 극수와 전기자의 슬롯수의 비를 변경한 새로운 구조의 단 1차형 영구자석 선형동기 전동기를 제안하였으며, 단부력을 줄이기 위하여 전기자의 길이 조정 및 챔퍼링을 통하여 영구자석 선형 동기 전동기를 설계하였다.