• 제목/요약/키워드: Low-Inertia

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Improvement of Low Speed Operation of Electric Machine Using ROELO for Inertia Identification (확장 루엔버거 관측기를 이용한 전동기의 저속 성능 향상)

  • Lee, Kyo-Bum;Song, Joong-Ho;Choi, Ik;Yoo, Ji-Yoon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.9 no.3
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    • pp.231-239
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    • 2004
  • A new scheme to estimate the moment of inertia in the motor drive system in very low speed is proposed in this paper. The simple estimation scheme, which is usually used in most servo system for low speed operation, is sensitive to the variation of the machine parameter, especially the moment of inertia. To estimate the motor inertia value, Reduced-Order Extended Luenberger Observer (ROELO) is applied. The effectiveness of the proposed inertia identification method using the RORLO is verified by simulation and experiment.

Instantaneous Speed and Mechanical Inertia Moment Estimation for the improvement of the Low Speed Control Characteristics of Induction Machines (유도전동기 저속 운전 특성 개선을 위한 순시 속도 및 기계관성모먼트 추정)

  • Hyun, Dong-Seok;Kim, Nam-Joon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.1 no.1
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    • pp.12-19
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    • 1996
  • The purpose of this paper is the improvement of the speed control characteristics of induction machines suited the low resolution incremental-type encoder in a low speed region. In order to improve the control characteristics in a low speed range, we propose that the instantaneous speed control method by the instantaneous speed detection which is implemented by the disturbance torque observer. Also, in case of the speed control by the instantaneous speed detection, the simple estimation method of the mechanical inertia moment is proposed. We will the carry out the mathematical verification of the proposed theory by the theoretic advisement connected with the convergence relationship of the estimated inertia moment to the real mechanical inertia moment. Computer simulations and experiments by the IGBT inverter adopting DSP is performed to verify the proposed method.

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Inaction Inertia Impacting Purchase Intention for Fashion Products and Moderation of Involvement

  • Eun-Jung Lee;Hye-Min Choi
    • International Journal of Internet, Broadcasting and Communication
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    • v.16 no.3
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    • pp.346-354
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    • 2024
  • Time-limited promotions have become a popular strategy across various product categories including fashion mobile platforms. While consumer feel content and satisfied when they get this , those who miss the opportunity may develop negative feelings and tend to give up on additional price discounts. This phenomenon, known as inaction inertia, has been a crucial subject of consumer behavior research. However, the underlying mechanism within the context of fashion consumption has yet to be discussed. This study investigated whether consumers show inaction inertia when purchasing fashion products and whether involvement moderates product purchases in inaction inertia situations. Hypotheses were tested through an online survey with 336 Korean participants based on fictitious purchase scenarios. In the results, the hypothesized negative influence of inaction inertia on purchase intention for fashion products was statistically confirmed. Furthermore, the hypothesized moderation effect of involvement in the mechanism was confirmed - only within the high (vs. low) age group. To explain, the negative effect of inaction inertia significantly decreases among older consumers of high (vs. low) involvement levels. We contributed to the related academic flow by performing an experimental study on inaction inertia, which had relatively little empirical research compared to the influence confirmed in practice so far. We also provided a novel idea by demonstrating that the moderating effect of product involvement differs depending on the age group.

An Improvement of Low Speed Operation of Electric Machine with Inertia Identification Using ROELO (축소 차원 확장 루엔버거 관성 추정기를 이용한 전동기 저속운전의 성능 개선)

  • Lee, Kyo-Beum;Yoon, Young-Chul;Song, Joong-Ho;Choy, Ick;Yoo, Bum-Jae;Yoo, Ji-Yoon
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.1090-1092
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    • 2003
  • A new scheme to estimate the moment of inertia in the motor drive system in very low speed is proposed in this paper. The simple speed estimation scheme, which is usually used in most servo system for low speed operation, is sensitive to the variation of the machine parameter, especially the moment of inertia. To estimate the motor inertia value, Reduced-Order Extended Luenberger Observer (ROELO) Is applied. The effectiveness of the proposed ROELO is applied by experiments.

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A passive vibration isolator with bio-inspired structure and inerter nonlinear effects

  • Jing Bian;Xu-hong Zhou;Ke Ke;Michael CH Yam;Yu-hang Wang;Yue Qiu
    • Structural Engineering and Mechanics
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    • v.88 no.3
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    • pp.221-238
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    • 2023
  • This paper developed and examined a novel passive vibration isolator (i.e., "X-inerter") motivated by combining a bio-inspired structure and a rack-pinion inerter. The bio-inspired structure provided nonlinear stiffness and damping owing to its geometric nonlinearity. In addition, the behavior was further enhanced by a gear inerter that produced a special nonlinear inertia effect; thus, an X-inerter was developed. As a result, the X-inerter can achieve both high-static-low-dynamic stiffness (HSLDS) and quasi-zero stiffness (QZS), obtaining ultra-low frequency isolation. Furthermore, the installed inerter can produce a coupled nonlinear inertia and damping effect, leading to an anti-resonance frequency near the resonance, wide isolation region, and low resonance peak. Both static and dynamic analyses of the proposed isolator were conducted and the structural parameters' influence was comprehensively investigated. The X-inerter was proven to be comparatively more stable in the ultra-low frequency than the benchmarking QZS isolator due to the nonlinear damping and inertia properties. Moreover, the inertia effect could suppress the bio-inspired structure's super- and sub-harmonic resonance. Therefore, the X-inerter isolator generally possesses desirable nonlinear stiffness, nonlinear damping, and unique nonlinear inertia, designed to achieve the ultra-low natural frequency, the anti-resonance property, and a wide isolation region with a low resonance peak.

The Improvement of low speed driving characteristics of induction motor by inertia moment identification. (관성 모멘트 동정에 의한 유도전동기의 저속운전 특성개선)

  • 이성근
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.2 no.4
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    • pp.627-634
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    • 1998
  • This paper proposes an algorithm which improves capacity of a state observer and low speed driving characteristics of a induction motor by inertia moment identification. In induction motet driving systems, it is difficult to obtain the accurate speed information by a low resolution encoder because the encoder pulses are very few in a low speed range. To improve this problem, state observer based on the Gopinath' theory which estimates speed and disturbance was designed, and disturbance rejection control was realized by application of the observer. Also, inertia moment of the motor was estimated and the nominal inertia of the observer was identified to minimize the error of estimated speed and disturbance. From the simulation and experimental results, it is showed that the proposed observer improved the transient response characteristics in low speed region below 6[rpm].

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Performance Improvement of Servo System in the Low Speed Operation Region Using RBFN Disturbance Observer (방사형 기저 함수망 외란관측기를 이용한 서보시스템의 저속응답 성능개선)

  • Lee Kyo-Beum;Yoo Ji-Yoon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.9 no.5
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    • pp.467-477
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    • 2004
  • A new scheme to estimate the moment of inertia in the servo motor drive system in very low speed is proposed in this paper. The typical speed estimation scheme in most servo system for low speed operation is sensitive to the variation of machine parameters, especially the moment of inertia. To estimate the motor inertia value, the observer using the Radial Basis Function Networks(RBFN) is applied. The effectiveness of the proposed inertia estimation method is verified by experiments. It is concluded that the speed control performance in the low speed region is improved with the proposed disturbance observer using RBFN.

A Inertia Load Test using a Low Frequency Synchronous PWM Technique of high efficiency for Electric car. (전동차용 고효율 저주파 동기 PWM을 이용한 관성부하 시험)

  • 이광주;정만규;고영철;장성영;방이석
    • Proceedings of the KSR Conference
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    • 1998.11a
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    • pp.233-240
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    • 1998
  • This paper presents a high efficiency low switching PWM technique for the propulsion system of Electric car. In order to achieve the continuous voltage control to six-step and a low harmonics with low switching frequency under 500㎐, the synchronous technique is combined with a space vector overmodulation and implemented by using DSP. Improved performance and a validation of proposed method is shown by the experimental results using a 1.65MVA IGBT VVVF inverter and inertia load equivalent to 160 tons electric cars.

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Inertia Identification of Electric Machine Using Extended Luenberger Observer at Low Speed Region (확장 루엔버거 관측기를 이용한 저속영역에서의 전동기 관성 추정)

  • Lee Kyo-Beum;Kang Ho-Jin;Song Joong-Ho;Choy Ick;Yoo Ji-Yoon
    • Proceedings of the KIPE Conference
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    • 2002.07a
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    • pp.142-145
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    • 2002
  • A new scheme to estimate machine inertia in low speed is proposed in this paper. It is necessary to consider the machine parameter of low speed instantaneous observer to precise control in servo system, which has frequent load variation and speed change. To estimate machine parameter, especially the moment of inertia, Reduced-Order Extended Luenberger Observer (ROELO) is applied. The effectiveness of the proposed ROELO is showed by simulation.

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A Study of the Effect of Inaction Inertia on Intention to Purchase Fashion Products -Focusing on Moderation of Price Levels- (무행동 관성 효과가 패션 상품의 구매 의도에 미치는 영향 -상품 가격대 조절효과를 중심으로-)

  • Choi, Hyemin;Lee, Eun-Jung
    • Journal of the Korean Society of Clothing and Textiles
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    • v.43 no.1
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    • pp.154-166
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    • 2019
  • Consumers believe it is more profitable to buy products at a discount price than at a fixed price. However, consumers who miss an opportunity for a discount would experience regret; consequently, they may also forgo a purchase despite experiencing regret if a subsequent opportunity was no more attractive than the initial one. This phenomenon has been conceptualized as inaction inertia. In this study we investigate if consumers showed behavior of inaction inertia under the situation of fashion products purchase as well as if price and involvement had a moderating effect on product purchase. The following are the results of the research based on an empirical investigation. First, according to the results of influence of inaction inertia on purchase intention, respondents exposed to scenario of experiencing similar price discount in the past, both under high-price situations and low-price situations, made statistically fewer responses than those exposed to situations without such experience; therefore, effect of inaction inertia could be confirmed. Second, the moderating effect of product price on relationships between inaction inertia and purchase intention was not statistically significant.