• Title/Summary/Keyword: electrical resistance method

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The High Resistance Measurement up to 100 PΩ using a Low Resistance, a Low Voltage Source and a Commercial Digital Multimeter

  • Yu, Kwang Min;Lee, Sang Hwa;Kang, Jeon Hong;Kim, Wan-Seop
    • Journal of Electrical Engineering and Technology
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    • v.13 no.3
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    • pp.1392-1397
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    • 2018
  • The potentiometric measurement result for a high resistance up to $100P{\Omega}$ using a low resistance, a low voltage source and a commercial digital multimeter(DMM) is presented. With the method, a resistance can be easily, fast and economically measured. Using the method, resistance ranges over the $10G{\Omega}$ range which is difficult to measure using a commercial DMM and resistance ranges between $100T{\Omega}$ and $100P{\Omega}$ which cannot measure using an insulation tester were measured within accuracy of a few percent. It is expected that it can be useful to determine the temperature and voltage effect of a high resistance and an insulation material because it uses a reference resistance with a low resistance, very low temperature and voltage effect. Besides, it is expected that it can be useful to calibrate a dc high voltage divider with a large resistance ratio and a very low resistance because arbitrary resistance ratio measurements are possible with it.

Measurement of the Ground Resistance using the Fall-of-Potential Method with the Vertically-placed Current and Potential Auxiliary Electrodes (전류 및 전위 보조전극을 수직으로 배치하는 전위강하법을 이용한 접지저항의 측정)

  • Lee, Bok-Hee;Kim, Ki-Bok;Kim, You-Ha
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.3
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    • pp.53-60
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    • 2012
  • The fall-of-potential method is commonly used in measuring the ground resistance of large-scaled grounding system and the current and potential auxiliary electrodes are horizontally arranged. Because the distances between the ground grid to be tested and auxiliary electrodes are limited in downtown areas, it is very difficult to measure accurately the ground resistance of large-scaled grounding system. In this paper, the fall-of-potential method of measuring the ground resistance with the vertically-placed current and potential auxiliary electrodes was examined and discussed. The validity and good accuracy of the proposed method of measuring the ground resistance were confirmed through various simulations and actual tests carried out in uniform and two-layer soil structures.

The developed connection method on Si PV module (결정질 태양전지 모듈의 개선된 Connection Method)

  • Ji, Yang-Geun;Kong, Ji-Hyun;Kang, Gi-Hwan;Yu, Gwon-Jong;Ahn, Hyung-Geun;Han, Deuk-Yeong
    • 한국태양에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.115-120
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    • 2009
  • In this paper, we measurement the resistance on the flat wire for PV module. There is some kind of flat wire that has different length and different contact area in the PV module. so we test the resistance on each case for analysis with common connection method. we measurement the electrical output characteristics and phenomenon of PV module that is applied new connetion method. by the result, The fill factor and electrical output characteristics on PV module are analyzed to getting better more then common connection method. Finally we recommend the developed connection method for diminishing of resistance on PV module. It enhance the electrical character more than common connection method.

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A Novel Control Method of Resistance Spot Welding Inverter using Dynamic Resistance Characteristics for Weld Quality Improvement (용접품질 향상을 위한 저항 스폿 용접용 인버터의 동저항 특성을 이용한 새로운 제어기법)

  • Kang, Sung-Kwan;Jung, Jae-Hun;Nho, Eui-Cheol
    • The Transactions of the Korean Institute of Power Electronics
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    • v.20 no.6
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    • pp.491-497
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    • 2015
  • This study proposes a new control method for a resistance spot welding inverter to improve weld quality. The proposed method is based on the dynamic resistance characteristics of steel sheets to be welded. A point in the second peak value of the dynamic resistance occurs during one shot of the welding current flow. A constant voltage control is applied from zero to the peak point, and a constant current control is adopted from the peak point to the end of the shot. The mixed mode control of the constant voltage and current guarantees high weld quality. Experiments are conducted with a 5 kA power supply and 0.5 mm steel sheets to compare quality. Experimental results show that weld quality is improved more than 10 times that of the conventional control method.

A Study on the Measurement of Grounding Resistance Using the Fall-of-Potential Method (전위강하법을 이용한 접지저항 측정법 개선에 관한 연구)

  • Park, Duk-Yul;Wee, Won-Seok;Ryu, Bo-Hyuk;Kim, Jung-Hoon
    • Proceedings of the KIEE Conference
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    • 1999.07c
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    • pp.1490-1492
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    • 1999
  • This paper shows the accuracy of 61.8% rule which is based on the fall-of-potential method in field measurement of earth resistances, and proposes the measurement method which is applicable to the industries. This paper also finds the minimum distance to obtain the horizontal position in the earth resistance curves, and Proposes the standard form for measurement of earth resistance using the fall-of-Potential method.

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The Capacity of Applying Electrical Resistance Probe in Natural Corrosion Tests of Vietnam

  • Pham, Thy San;Le, Thi Hong Lien;Le, Quoc Hung
    • Corrosion Science and Technology
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    • v.2 no.2
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    • pp.98-101
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    • 2003
  • The Electrical Resistance Probe of carbon steel and weight loss coupons were exposed in atmosphere and in the lake water of Hanoi. The comparison of data received by two methods after one year exposure was presented. The correspondence of the data of these methods on the exposure time in both environments showed a capacity of using Electrical Resistance Probe in Vietnamese natural corrosion testing of Carbon steel.

A Study on the Thermal Analysis of Fire-Resistance Cable using FEM (유한요소법을 이용한 내화전선의 열해석에 관한 연구)

  • 오홍석;이상호
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.53 no.5
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    • pp.338-343
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    • 2004
  • In general, the insulation and protective sheaths on electrical conductors are made of combustible substances like PVC, natural or synthetic rubbers, and other organic or synthetic materials. When an electrical fire starts due to overheating of conductors/joints or sparking/arcing, the first thing to ignite is usually the insulation on the cables. When the insulation bums, the produced fumes are very toxic. To solve the problem, we have surely need the fire resistance cable that doesn't bum in a high temperature and emit toxic fume for operating a disaster prevention installation. In this paper, we have simulated the thermal analysis for the fire resistance cable according to the values of current in a overload and a short, and the values of outside flame with the fire resistance cable of the L's company product(600 V, FR-8 : Four Core) using the finite element method(Flux2D).

Modeling and Experimental Verification of ANN Based Online Stator Resistance Estimation in DTC-IM Drive

  • Reza, C.M.F.S.;Islam, Didarul;Mekhilef, Saad
    • Journal of Electrical Engineering and Technology
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    • v.9 no.2
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    • pp.550-558
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    • 2014
  • Direct Torque controlled induction motor (DTC-IM) drives use stator resistance of the motor for stator flux estimation. So, stator resistance estimation properly is very important for a stable and effective operation of the induction motor. Stator resistance variations because of changing in temperature make DTC operation difficult mainly at low speed. A method based on artificial neural network (ANN) to estimate the stator resistance online of IM for DTC drive is modeled and verified in this paper. To train the neural network a back propagation algorithm is used. Weight adjustment of neural network is done by back propagating the error signal between measured and estimated stator current. An extensive simulation has been carried out in MATLAB/SIMULINK to prove the efficacy of the proposed stator resistance estimator. The simulation & experimental result reveals that proposed method is able to obtain precise torque and flux control at low speed.

Study on the application of antenna method for the criterion test of insulator arc resistance (절연체의 내아크성 평가를 위한 안테나 기법의 적용에 관한 연구)

  • Lee, K.W.;Kim, M.Y.;Kang, S.H.;Lim, K.J.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.05b
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    • pp.57-60
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    • 2004
  • Electrical arc is the final stage of insulation breakdown and has high current density which cause heat and light in insulator. Insulator under electrical arc lost its insulating strength and eternal damages. Conventional criterion of electrical arc resistance in Standards have depended on the change of sound pressure and light color after damages on insulator by electrical arc. The recognition of these changes is done by human himself which was very subjective and resulted in some error to judge whether insulator has damages or not. This paper has shown that antenna method is the appropriate measure to judge electrical arc resistance for insulator. Antenna measures the electromagnetic waves radiated from tungsten electrodes with 6mm gap regulated by KSC2130. Applied voltage cross two tungsten electrodes have two different methods such as 1/8 10 and continuous 10mA. Signal amplitudes obtained by antenna has diminished after the damage of insulator, which will provide objective and good way to judge the electrical arc resistance.

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Image Reconstruction of Subspace Object Using Electrical Resistance Tomography

  • Boo Chang-Jin;Kim Ho-Chan;Kang Min-Jae
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.6 no.1
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    • pp.47-51
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    • 2006
  • Electrical resistance tomograpy (ERT) maps resistivity values of the soil subsurface and characterizes buried objects. The characterization includes location, size, and resistivity of buried objects. In this paper, truncated least squares (TLS) is presented for the solution of the ERT image reconstruction. Results of numerical experiments in ERT solved by the TLS approach is presented and compared to that obtained by the Gauss-Newton method.