• Title/Summary/Keyword: electrical parameters.

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A Method for Determination of 3D-Electrical Discharge Machining Parameters Using Z-map (Z-map을 이용한 3차원 방전가공조건의 결정방법)

  • 주상윤;이건범
    • Korean Journal of Computational Design and Engineering
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    • v.4 no.4
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    • pp.355-359
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    • 1999
  • This paper presents a method for determining machining parameters in electrical discharge machining process (EDM) based on discharge area. The parameters are the peak value of currents, the pulse-on time, and the pulse-off time, on which the EDM performance depends chiefly. The optimal machining parameters are closely related on discharge area, which can be calculated from a tool electrode and a discharge height. In the paper the discharge area is obtained from NC code for machining the tool electrode instead of its geometric model. The method consists of following three steps. First a Z-Map model is constructed from the NC code. Secondly, the discharge area is obtained from the Z-Map model and a Z-height. Finally, the machining parameters are calculated from the discharge area. An introduced example shows that the machining parameters are calculated by the using a Z-map model obtained from the machining data for a tool electrode.

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Optimal Design of a Planar-Type Antenna with a Reduced Number of Design Parameters Using Taguchi Method and Adaptive Particle Swarm Optimization

  • Lee, Jeong-Hyeok;Jang, Dong-Hyeok;Kim, Hyeong-Seok
    • Journal of Electrical Engineering and Technology
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    • v.9 no.6
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    • pp.2019-2024
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    • 2014
  • This paper presents a method to optimize the design of a planar-type antenna and reduce the number of design parameters for rapid computation. The electromagnetic characteristics of the structure are analyzed, and Taguchi method is used to identify critical design parameters. Adaptive particle swarm optimization, which has a faster convergence rate than particle swarm optimization, is used to achieve the design goal effectively. A compact dual-band USB dongle antenna is tested to verify the advantage of the proposed method. In this case, we can use only five selected geometrical parameters instead of eighteen to accelerate the optimization of the antenna design. The 10 dB bandwidth for return loss ranges from 2.3 GHz to 2.7 GHz and from 5.1 GHz to 5.9 GHz, covering all the WiBro, Bluetooth, WiMAX, and 802.11 b/g/n WLAN bands in both simulation and measurement. The optimization process enables the antenna design to achieve the required performance with fewer design parameters.

Parameters Optimization of Impulse Generator Circuit for Generating First Short Stroke Lightning Current Waveform

  • Eom, Ju-Hong;Cho, Sung-Chul;Lee, Tae-Hyung
    • Journal of Electrical Engineering and Technology
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    • v.9 no.1
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    • pp.286-292
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    • 2014
  • This paper presents the parameters optimization technology for generating the first short stroke lightning current waveform($10/350{\mu}s$) which is necessary for the performance tests of components of lightning protection systems, as required under IEC 62305 and the newly amended IEC 62561. The circuit using the crowbar device specified in IEC 62305 was applied to generate the lightning current waveform. To find the proper parameters of the circuit is not easy because the circuit consists of two parts; circuit I, which relates to the front of current waveform, and circuit II, which relates to the tail. A simulation in PSpise was carried out to find main factors related to the front and tail of $10/350{\mu}s$. The lightning current generator was developed by utilizing the circuit parameters found in the simulation. In the result of experiments, new parameters of the circuits need to be changed because of the difference between the simulation and the experiment results. Using the iterative method, the optimized parameters of the circuits was determined. Also a multistage-type external coil and a damping resistor were proposed to make the efficiency of generation to enhance. According to the result in this paper, an optimized first short stroke lightning current waveform was obtained.

Transient Analysis of Magnetodynamic Systems Using Frequency-dependent Circuit Parameters (주파수 의존적인 회로상수를 이용한 시변자장 시스템의 과도상태 해석)

  • Choi, Myung-Jun;Lee, Se-Hee;Park, Il-Han
    • Proceedings of the KIEE Conference
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    • 1999.07a
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    • pp.61-63
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    • 1999
  • This paper presents an efficient method for analysis of magnetodynamic system using frequency-dependent parameters. In equivalent electric circuit of linear magnetodynamic system, parameters of inductance and resistance are not constant since they vary with its driving frequency. Once frequency-dependent parameters of equivalent electric circuit for a given system are extracted, they can be used to analyze various characteristics of system. We use the Fourier transform, the high-order sensitivity method and Taylor series in order to efficiently extract the frequency-dependent parameters of magnetodynamic system. The proposed algorithm is applied to an induction heating system to validate its numerical efficiency.

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Design Variable Parametrization in Finite Element Models for Optimal Design of Electromagnetic Devices (전기기기의 최적설계를 위한 유한요소모델의 설계변수 매개화)

  • Kim, Chang-Hyun;Kim, Chang-Wook;Park, Il-Han
    • Proceedings of the KIEE Conference
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    • 1998.07a
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    • pp.146-148
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    • 1998
  • For the shape design of electromagnetic devices using the FEM, the choice of design parameters influence to the success of the optimization process. If the design parameter distribution has a one to one corespondence with finite element model, we can encounter not only serious accuracy problem but also obtain a zigzag shape along the interface. The nodes between those design parameters can be parameterized by interpolating using one among many interpolation methods. The conventional parameterization of design parameters has a limit of application for shape, because design parameters and movable nodes are linearly intepolated. In this paper, using the B-spline curve that use to present any interfaces in computer graphics, the curvilinear parameterization between design parameters and node points is compared with the linear parameterization.

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Real-Time Harmonic Parameters Analyzer for Evaluating Induction Motor Drive System (유도전동기 구동시스템 평가를 위한 실시간 고조피 파라미터 분석장치)

  • Lim, Young-Cheol;Jung, Young-Gook
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.479-483
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    • 1997
  • In general, motor parameters can be divided into mechanical/electrical parameters and harmonic parameters. Mechanical/electrical parameters identification of motor have been studying systematically for a long time. But, systematical study on harmonic parameters analysis for efficient motor drive system are very poor. The goal of this paper is to propose analyzing method of harmonic parameters for motor drive system with various experimental graphic screens and numerical results and to develope harmonic parameters analyzer. A developed analyzer is made up 586-PC and DSP (digital signal processor) board, motor drive system, power and harmonic parameters analyzing software for windows. Harmonic parameters are analyzed using correlation signal processing techniques based on the correlation between voltage and current waveforms. Analysis results are visualized by 3-D current coordinates, and it is compared and evaluated with conventional time/frequency domain. To verify the validity of the proposed system, 1/4HP capacitor run type single phase induction motor and thyristor speed controller is used for analyzing. Harmonic parameters of motor drive system is analyzed and verified, with varying fire angle of thyristor speed controller, and the proposed approach is to confirm validity.

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Experimental Investigation of Size Dependent Electrical Parameters of Tuning Fork Crystal Oscillators (소리굽쇠 수정발진기의 크기에 따른 전기적인 특성변화에 대한 실험적 연구)

  • Song, Sang-Hun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.12
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    • pp.2416-2419
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    • 2009
  • We performed frequency response measurements of four tuning fork crystal oscillators with different sizes and analyzed their measured electrical equivalent circuit parameters of R, L, $C_S$, and $C_P$ as functions of the linear dimensions, length, width, and thickness. We observed that R and L showed an decreasing behavior with increasing length while $C_S$, and $C_P$ showed an increasing behavior. Similar dependences of the electrical parameters on thickness were also observed. On the contrary, any noticeable dependence of these parameters on width has not been found.

Optimization of the fuzzy model using the clustering and hybrid algorithms (클러스터링 및 하이브리드 알고리즘을 이용한 퍼지모델의 최적화)

  • Park, Byoung-Jun;Yoon, Ki-Chan;Oh, Sung-Kwun;Jang, Seong-Whan
    • Proceedings of the KIEE Conference
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    • 1999.07g
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    • pp.2908-2910
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    • 1999
  • In this paper, a fuzzy model is identified and optimized using the hybrid algorithm and HCM clustering method. Here, the hybrid algorithm is carried out as the structure combined with both a genetic algorithm and the improved complex method. The one is utilized for determining the initial parameters of membership function, the other for obtaining the fine parameters of membership function. HCM clustering algorithm is used to determine the confined region of initial parameters and also to avoid overflow phenomenon during auto-tuning of hybrid algorithm. And the standard least square method is used for the identification of optimum consequence parameters of fuzzy model. Two numerical examples are shown to evaluate the performance of the proposed model.

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Parameter Identification of a Synchronous Reluctance Motor by using a Synchronous PI Current Regulator at a Standstill

  • Hwang, Seon-Hwan;Kim, Jang-Mok;Khang, Huynh Van;Ahn, Jin-Woo
    • Journal of Power Electronics
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    • v.10 no.5
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    • pp.491-497
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    • 2010
  • This paper proposes an estimation algorithm for the electrical parameters of synchronous reluctance motors (SynRMs) by using a synchronous PI current regulator at standstill. In reality, the electrical parameters are only measured or estimated in limited conditions without fully considering the effects of the switching devices, connecting wires, and magnetic saturation. As a result, the acquired electrical parameters are different from the real parameters of the motor drive system. In this paper, the effects of switching devices, connecting wires, and the magnetic saturation are considered by simultaneously using the short pulse and closed loop equations of resistance and synchronous inductances. Therefore, the proposed algorithm can be easily and safely implemented with a reduced measuring time. In addition, it does not need any external or additional measurement equipment, information on the motor's dimensions, and material characteristics as in the case of FEM. Several experimental results verify the effectiveness of the proposed algorithm.

A Practical Identification Method for Robot System Dynamic Parameters (로보트시스템 동적 변수의 실용적인 추정 방법)

  • Kim, Sungkwun
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.7
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    • pp.765-772
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    • 1990
  • A practical method of identifying the inertial parameters, viscous friction and Coulomb friction of a robot is presented. The parameters in the dynamic equations of a robot are obtained from the measurements of the command voltage and the joint position of the robot. First, a dynamic model of the integrated system of the mainpulator and motor is derived. An off-line parameter identification procedure is developed and applied to the University of Minnesota Direct Drive Robot. To evaluate the accuracy of the parameters the dynamic tracking of the robot was tested. The trajectroy errors were significantly reduced when the identified dynamic parameters were used.

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