• Title, Summary, Keyword: current waveform

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An Experimental Study on the Effect of Troubles of Solenoid Injector on Fuel Injection Quantity of CRDI Diesel Vehicle (CRDI 디젤 엔진의 솔레노이드 인젝터 불량이 연료 분사량에 미치는 영향에 관한실험적 연구)

  • Kang, Sung-Gu;Yoo, Jong-Sik;Kim, Chul-Soo
    • Journal of the Korean Society of Mechanical Technology
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    • v.19 no.6
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    • pp.809-814
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    • 2017
  • This paper investigates the relationship between the waveform area and fuel injection quantity. It is on developing on analysis method of waveform the effect of waveform area on fuel injection quantity of CRDI Diesel engine. The experimental methods using Pico oscilloscope and fuel injection tester are employed to measure current and voltage waveform and fuel injection quantity of solenoid injector. The one normal and two abnormal solenoid injectors are used. The experiment is carried out during no-load condition. A summary of the important results are as follows. 1) The area of the voltage and current waveform of the abnormal injector becomes larger than the that of normal injector, and the area of the current and voltage waveform is inversely proportional to the fuel injection quantity. 2) The area of the current waveform can be obtained more accurate results than that of voltage waveform. 3) It is possible to infer the fuel injection quantity by measuring the current waveform and calculating the area.

Fault Current Waveform Analysis of a Flux-Lock Type SFCL According to LC Resonance Condition of Third Winding

  • Lim, Sung-Hun
    • Journal of Electrical Engineering and Technology
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    • v.3 no.2
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    • pp.213-217
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    • 2008
  • The flux-lock type superconducting fault current limiter(SFCL) can apply the magnetic field into the high-$T_C$ superconducting(HTSC) element by adopting the magnetic field coil in its third winding. To apply the magnetic field into the HTSC element effectively, the capacitor for LC resonance is connected in series with the magnetic field coil. However, the current waveform of third winding for the application of the magnetic field is affected by the LC resonance condition for the frequency of the source voltage and can affect the waveform of the limited fault current. In this paper, the current waveform of the third winding in the flux-lock type SFCL according to LC resonance condition during a fault period was analyzed. From the differential equation for its electrical circuit, the current equation of the third winding was derived and described with the natural frequency and the damping ratio as design parameters. Through the analysis according to the design parameters of the third winding, the waveform of the limited fault current was confirmed to be influenced by the current waveform of the third winding and the design condition for the stable fault current limiting operation of this SFCL was obtained.

A Study on Welding Process Algorithm through Real-time Current Waveform Analysis (실시간 공정신호를 통한 용접공정 알고리즘에 관한 연구)

  • Yoon, Jin Young;Lee, Young Min;Shin, Soon Cheol;Choi, Hae Woon
    • Journal of Welding and Joining
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    • v.33 no.4
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    • pp.24-29
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    • 2015
  • The current waveform was analysed to monitor the weld quality in real time process. The acquired current waveform was discretely analysed for the top and bottom limits of peaks as well as the pulse frequency measurement. Fast Fourier Transform was implemented in the program to monitor the pulse frequency in real time. The developed algorithm or program was tested for the validation purpose. The cross-section of weld profile was compared to the current waveform profile to correlate the monitored signal and the actual parts. Pulse frequency was also used as auxiliary tool for the quality monitoring. Based on the results, it was possible to evaluate the quality of welding by measure the current waveform profile and frequency measurement.

High-efficiency Operation of Switched Reluctance Generator based on Current Waveform Control

  • Li, Zhenguo;Yu, Siyang;Ahn, Jin-Woo
    • Journal of international Conference on Electrical Machines and Systems
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    • v.2 no.1
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    • pp.120-126
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    • 2013
  • The main aim of this paper is to expound high-efficiency operation of Switched Reluctance Generator (SRG) based on the current waveform. For this purpose, theoretical analysis of the copper loss and iron loss of the system is done first. Then, necessary simulation is done to find the variation trend of the copper loss and iron loss with the variation of the current waveform at the same output power. Finally, the best current waveform which can make the system operate with high efficiency is obtained by considering the influence of these two kinds of loss. In order to verity the simulation results, the experimental platform of DC motor-SRG is built and the modified angle position control (APC) method which can specify the current shape optionally is presented. By comparing the system efficiency at the three kinds of typical current waveform, the correctness and feasibility of the theory is verified. The proposed method is simple, reliable, and easy to achieve.

Resistance Spot Welding Characteristics of Mg Alloy Applying Current Waveform Control (전류 파형 제어를 적용한 마그네슘 합금의 저항 점 용접 특성)

  • Choi, Dong-Soon;Hwang, In-Sung;Kim, Dong-Cheol;Ryu, Jae-Wook;Kang, Moon-Jin
    • Journal of Welding and Joining
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    • v.32 no.2
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    • pp.70-75
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    • 2014
  • In automotive industry, applying of Mg alloy to autobody has been issued recently as a light metal. But poor resistance spot weldability of Mg alloy is blocking commercialization. So studies on improving resistance spot weldability of Mg alloy is increasing continuously. For reduce loss of heat input during welding, inverter DC power source is considered because of short rise time to target welding current. But rapid rising of welding current can increase temperature rapidly in nugget and oxide film between electrode and base metal, and that causes generating expulsion on low welding current range. In this study, for increase optimum welding current range and prevent generating expulsion, applicate various types of welding current waveform controls during resistance spot welding. For analysis effects of each current waveform control, acceptable welding current regions according to electrode force and welding time is determined and lobe diagram is derived. In result, pre heat is proposed as optimum type of welding current waveform control.

Characteristics on Arc Waveform and RMS of Current by Conductive Powder (도전성 분말에 의한 아크전류의 파형 및 실효값 특성)

  • Kim, Doo Hyun;Kang, Yang Hyun
    • Journal of the Korean Society of Safety
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    • v.28 no.3
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    • pp.63-68
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    • 2013
  • This paper is aimed to make an analysis on characteristics of the parallel arc waveform and RMS of current at the electrical tracking state by conductive powder. In order to achieve the goal in this paper, field state investigation at metal processing companies in Chung-Nam province area was conducted. With the field state investigation, conductive powder were collected from metal processing companies. By experiment on electrical connector(breaker, connector) over which the conductive powder were scattered, arc waveform and RMS of current were measured. The measured waveform and RMS(root-mean-square) of current were analyzed to describe characteristics and patterns of electrical arc by the conductive powder. It was proved that conductive powder on electrical connector can flow electrical current enough to make electrical fire with high thermal energy. Also the change of sine waveform and RMS of current can be used to find out relationship between electrical fire and fault signal by conductive powder. The results obtained in this paper will be very helpful for the prevention of electrical fires occurred at the metal processing companies.

Analysis on Eddy Current Losses for Cylindrical Linear Oscillatory Actuator with Halbach Array according to Drive Voltage Waveform (영구자석 Halbach형 원통형 액추에이터의 구동전압 파형에 따른 와전류 손실)

  • Jang, Seok-Myeong;Kim, Hyun-Kyu;Park, Ji-Hoon;Ko, Kyoung-Jin;Choi, Jang-Young;Kim, Il-Jung
    • Proceedings of the KIEE Conference
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    • pp.49-51
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    • 2009
  • This paper deals with the analysis on eddy current losses for cylindrical linear oscillatory actuator (LOA) with Halbach array mover according to voltage waveform. This paper presents analytical procedures for calculation of eddy current losses using Poynting theorem. On the basis of the magnetic vector potential and a two-dimensional (2-d) cylindrical coordinate system, this paper derived analytical solutions of eddy current tosses using phase current analysis. The eddy current losses of each harmonic obtained by fast Fourier transform (FFT) analysis of phase current are compared with results obtained from finite-element method (FEM). Particularly, this paper shows that the eddy current losses of cylindrical LOA according to square voltage waveform are more significant than those according to sinusoidal voltage waveform.

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Current waveform Control of Pulse MAG Welding Power Source for High Speed Welding of Thin Plates (박판의 고속용접을 위한 펄스MAG 용접전원의 파형제어에 관한 연구)

  • Gu, Heon-Hoe;Kim, Tae-Jin;Kim, Jun-Hong;Lee, Hyeon-U;Jo, Sang-Myeong
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.48 no.10
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    • pp.571-578
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    • 1999
  • Current waveform control of pulse MAG welding power source is studied so that welding of thin plates may obtain high speed and improved performance. In this paper, waveform control method is proposed, digital controller using DSP is able to control the current waveform precisely. High speed welding of thin plates using pulse MAG welding method is made possible. Performance test for 1.2mm thin plates is carried out, output waveform and welding performance is analyzed.

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A Study on the Metal Transfer and Spatter Generation in High Current $CO_2$ Welding (고전류 $CO_2$용접에서의 금속이행 및 스패터 발생 현상에 관한 연구)

  • 김남훈;유회수;김희진;고진현
    • Journal of Welding and Joining
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    • v.21 no.3
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    • pp.51-57
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    • 2003
  • The metal transfer in $CO_2$ welding shows the transition of transfer mode from short-circuiting to repelled transfer will the increase of welding current. While the short-circuiting mode in $CO_2$ welding has been studied very extensively relating with droplet formation and spatter generation, the repelled transfer has little been understood. In this study, high current $CO_2$ welding has been performed with bead-on-plate welds along with the waveform analyzer and high speed camera. The image of high speed camera was synchronized with its waveform so that the moment of spatter generation could be realized during drop detachment. As a results of this study, it was found that welding arc changes its location either once or three times and thus single or double pulse signals were developed in the voltage waveform. Whenever the arc moved its location, new arc was developed in a explosive way and thus it caused spatter generation. Specially severe spattering took place when the waveform showed a double-peak pattern. As a consequence of these results, new waveform control techniques could be suggested for suppressing the spatter generation in the high-current $CO_2$ welding.

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.