• Title, Summary, Keyword: pulse type excitation

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Rocking response of self-centring wall with viscous dampers under pulse-type excitations

  • Zhang, Lingxin;Huang, Xiaogang;Zhou, Zhen
    • Earthquakes and Structures
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    • v.19 no.3
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    • pp.215-226
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    • 2020
  • A self-centering wall (SCW) is a lateral resistant rocking system that incorporates posttensioned (PT) tendons to provide a self-centering capacity along with dampers to dissipate energy. This paper investigates the rocking responses of a SCW with base viscous dampers under a sinusoidal-type pulse considering yielding and fracture behaviour of the PT tendon. The differences in the overturning acceleration caused by different initial forces in the PT tendon are computed by the theoretical method. The exact analytical solution to the linear approximate equation of motion is also provided for slender SCWs. Finally, the effects of the ductile behaviour of PT tendons on the rocking response of a SCW are analysed. The results demonstrate that SCWs exhibit two overturning modes under pulse excitation. The overturning region with Mode 1 in the PT force cases separates the safe region of the wall into two parts: region S1 with an elastic tendon and region S2 with a fractured tendon. The minimum overturning acceleration of a SCW with an elastic-brittle tendon becomes insensitive to excitation frequency as the PT force increases. After the plastic behaviour of the PT tendon is considered, the minimum overturning acceleration of a SCW is increased significantly in the whole range of the studied wg/p.

Effect of Tooth Shape and Unbalanced M.M.F on Static Thrust Force Characteristics of Linear Pulse Motor (리니어 펄스 모터에서 치 형상과 기자력 불평형이 정추력 특성에 미치는 영향)

  • Lee, Dong-Ju;Lee, Eun-Ung;Kim, Seong-Heon;Kim, Seong-Jong
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.3
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    • pp.131-137
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    • 2000
  • 2 phase 8 pole HB-type(flat-type) Linear Pulse Motor can be used as the high precision position actuator because of its many advantages (simple control circuit, high stiffness characteristics, etc). Also, using the microstep drive, its noise and vibration can be reduced considerably and positional resolution may be increased further. But, $20^{\circ}$tapered tooth shape to reduce the normal force have an much effect on the static thrust force characteristics. And, because of hybrid-type LPM, interaction between the permanent magnet and the excitation current have an effect on the various characteristics of LPM. Hence, in this paper, the effect of tooth shape on static thrust force characteristics was analyzed using the air gap permeance by finite element method. For analyzing the effect of unbalance between the m.m.f of permanent magnet and the m.m.f of excitation current, unbalanced m.m.f coefficient $\sigma$ were introduced with the permenace matrix and switching matrix.

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Dynamic response of post-tensioned rocking wall-moment frames under near-fault ground excitation

  • Feng, Ruoyu;Chen, Ying;Cui, Guozhi
    • Earthquakes and Structures
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    • v.15 no.3
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    • pp.243-251
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    • 2018
  • The dynamic responses of a rocking wall-moment frame (RWMF) with a post-tensioned cable are investigated. The nonlinear equations of motions are developed, which can be categorized as a single-degree-of-freedom (SDOF) model. The model is validated through comparison of the rocking response of the rigid rocking wall (RRW) and displacement of the moment frame (MF) against that obtained from Finite Element analysis when subjected ground motion excitation. A comprehensive parametric analysis is carried out to determine the seismic performance factors of the RWMF systems under near-fault trigonometric pulse excitation. The horizontal displacement of the RWMF system is compared with that of MF structures without RRW, revealing the damping effect of the RRW. Frame displacement spectra excited by trigonometric pulses and recorded earthquake ground motions are constructed. The effects of pulse type, mass ratio, frame stiffness, and wall slenderness variations on the displacement spectra are presented. The paper shows that the coupling with a RRW has mixed results on suppressing the maximum displacement response of the frame.

A Basic Study for the Control Circuit of 2-phase 8-pole HB type Linear Pulse Motor (2상 8극 HB형 리니어펄스모터의 제어회로구성을 위한 기초연구)

  • Kim, Sung-Hun;Kim, Il-Jung;Lee, Eun-Woong
    • Proceedings of the KIEE Conference
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    • pp.135-137
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    • 1994
  • In this paper, step response, speed, maximum frequency characteristics of 2-phase, 8-pole, HB type, prototype linear pulse motor(LPM) were investigated with the open loop control system(OLCS) being attached to the LPH. In this experiment, both 1-phase and 1-2 phase excitation types were adopted and microcomputer was used in deal with the data. The results point to some directions for the improvement of the open loop control system.

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Proper excitation voltage and fixed switching angle control scheme for SRM drive (SMR구동을 위한 적정여자전압 고정스위칭각 제어방식)

  • 안영주;안진우;조철제;황영문
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.1
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    • pp.54-59
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    • 1996
  • As the current shape of SRM is of pulse type and changed by the motor parameters and drive conditions, the influences on the drive efficiency by control method are more than other types of motors. In this paper, a proper excitation condition to drive a SRM with high efficiency is proposed and tested. It is derived from the conditions that the phase current of a SRM is to be flat-topped at various drive. The saturation effect of magnetic circuit is accounted for more accurate analysis. Experimental tests are executed to verify the proposed excitation method. This drive system is easy to commutate and also advantageous in reducing torque ripple. (author). 6 refs., 10 figs., 1 tab.

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A Study on the Dual PWM Digital Excitation System of Regeneration Type (회생형 이중화 PWM 방식의 디지털 여자시스템에 관한 연구)

  • Ryu, Ho-Seon;Lee, Joo-Hyun;Lim, Ick-Hun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.9
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    • pp.79-84
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    • 2010
  • This paper discusses the control of generator field using dual IGBT PWM regeneration method to target brushless synchronous generator. If one of PWM bridges happens to fault, it transfers automatically and can be in charge of full load. Also it has an advantage of the operation which UPS connected in parallel with PWM bridge can supply power to excitation system in condition of main power loss. This PWM system supplies field current to generator in one quadrature operation, regenerates field coil energy to main power supplier in four quadrature operation. We designed, manufactured and applied the first trial product at J-power plant.

On a Reduction of Codebook Searching Time by using RPE Searching Tchnique in the CELP Vocoder (RPE 검색을 이용한 CELP 보코더의 불규칙 코드북 검색)

  • 김대식
    • Proceedings of the Acoustical Society of Korea Conference
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    • pp.141-145
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    • 1995
  • Code excited linear prediction speech coders exhibit good performance at data rates as low as 4800 bps. The major drawback to CELP type coders is their large computational requirements. In this paper, we propose a new codebook search method that preserves the quality of the CELP vocoder with reduced complexity. The basic idea is to restrict the searching range of the random codebook by using a searching technique of the regular pulse excitation. Applying the proposed method to the CELP vocoder, we can get approximately 48% complexity reduction in the codebook search.

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Time domain Reduction Method for Electromagnetic Transients Study: Equivalent Driving-Point Impedance Model using Prony Analysis (과도현상 해석을 위한 시간 영역에서의 등가축약법 :프로니 해석기법을 이용한 등가 구동점 임피던스 모델의 구성)

  • 홍준희;박종근
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.43 no.4
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    • pp.687-690
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    • 1994
  • This paper presents a method of obtaining transmission network equivalents from the network's response to the pulse excitation signal. Proposed method is base on Prony signal analysis and jtransfer function identification technique. As a result Thevenin-type of discrete-time filter model can be generated. It can reproduce the driving point impedance characteristic of the network.

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Analysis of Xenon Flash Lamp Discharge System for Laser Excitation (레이저 발진용 세논기체 섬광관의 방전계통해석)

  • 김영권;이문기
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.5 no.3
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    • pp.25-30
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    • 1968
  • The characteristics of single mesh discharge circiut for Xenon flashlamp has been analysised in detail. Since flashlamp voltage characteristics is linear in time, though nonlinear in current, the nonliear differential equation , for this system has beens solved by the analog computer. Also for given lamp type, energy input, pulse duration, and pulse shape factor, the inductance, capacatince and operating voltage were discussed.

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Force Characteristic Analysis of Airflow Type Linear Pulse Mortor by Permeance Method (패미언스법에 의한 공압 부상형 리니어 펄스모터의 힘 특성 해석)

  • 김일남;백수현;윤신용
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.13 no.4
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    • pp.160-169
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    • 1999
  • Linear pulse rootor (LPM) be suitable a field where smooth linear rootion of high precision is required, because it's structured with minute teeth pitch in airgap of between and stator and roover(forcer). Force and position of LPM are effected sensitively by the teeth pitch, air gap, permanent magnet and excitation current. So, LPM is much important to analyze the force characteristics. llis paper was awlied to perrreance roothed for force calculation at airgap. The airgap of LPM is maintained from the pressure generated by an air-bearing. Simplified airflow and permeance methods will be used to calculate the air gap under static conditions. Therefore, the maximum available force is then derived using the coenergy method with variable air gap, also normal force and linear thrust was acquired from variable minute displacement 1[mm]. 1[mm].

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