• Title, Summary, Keyword: Series and parallel connections

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Quench Characteristics of Superconducting Elements using Reactors at Series and Parallel Connections (직·병렬연결시 리액터를 이용한 초전도 소자의 퀜치 특성)

  • Choi, Hyo-Sang;Lim, Sung-Hun;Cho, Yong-Sun;Nam, Gueng-Hyun;Lee, Na-young;Park, Hyoung-Min
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.9
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    • pp.863-869
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    • 2005
  • We investigated quench characteristics of superconducting elements connected in series and parallel each other. The serial and parallel connections of superconducting elements causes a difficulty in simultaneous quench due to slight difference between their critical current densities. In other to induce simultaneous quench, we fabricated four type circuits; serially connected circuit before parallel connection, the circuit connected in parallel before serial connection, serially connected circuit before parallel connection with reactors, the circuit connected in Parallel before serial connection with reactors. We confirmed that the simultaneous quenches occurred in serial and parallel connections of superconducting elements using reactors. In addition, the power burden of superconducting elements was smaller than those of serial and parallel connections of superconducting elements without reactors.

Characteristics of a Hybrid-type SFCL with Serial and Parallel Connection of Secondary Circuit (2차회로의 직.병렬연결에 따른 하이브리드형 초전도 한류기의 특성)

  • Cho, Yong-Sun;Park, Hyoung-Min;Nam, Goung-Hyun;Lee, Na-Young;Han, Tae-Hee;Choi, Choi-Sang
    • Proceedings of the KIEE Conference
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    • pp.393-395
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    • 2006
  • We investigated the operational characteristics of the hybrid-type superconducting fault current limiter (SFCL) according to the serial and parallel connections of secondary circuits. The hybrid-type SFCL consists of a transformer, which has a primary winding and several secondary windings with $YBa_2Cu_3O_7$ films connected in series and parallel. In order to increase the capacity of the SFCL, the serial connection between each current limiting unit is necessary. The hybrid-type SFCL with the serial connection in secondary circuits could show superior characteristics than those of the parallel connections in the current limiting and quench time. The resistances generated in the superconducting units were also lowered at the parallel connections. We confirmed that the parallel connection reduced the power burden of each superconducting unit under the same conditions because of the simultaneous quenching between superconducting units.

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Improvement of Quench Properties of a Flux-Lock Type Superconducting Fault Current Limiter by the Connection Method of YBCO Elements (YBCO소자의 연결방법에 의한 자속구속형 초전도 한류기의 퀜치특성의 향상)

  • Chung, Soo-Bok;Park, Hyoung-Min;Choi, Hyo-Sang
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.57 no.3
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    • pp.323-327
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    • 2008
  • We investigated the quench characteristics of a flux-lock type superconducting fault current limiter (SFCL) depending on the methods of the serial and parallel connections between the superconducting elements. The flux-lock type SFCL consists of two coils. The primary coil is wound in parallel to the secondary coil through an iron core, and the secondary coil is connected to the superconducting elements in series and parallel. In this paper, the analyses of voltage, current, and resistance of the superconducting elements connected in serial and parallel were performed to increase the power capacity of the flux-lock type SFCL. A part of the superconducting elements was not quenched in $2{\times}2$ serial connection between the elements and then the power burden of the quenched elements was increased. However the elements with $2{\times}2$ parallel connection was all quenched. This means that the power burden of each superconducting element can be reduced under the same conditions. We found that $2{\times}2$ parallel connection was more profitable for the current limiting effects and the increase of the power capacity.

Output Characteristics of Parallel or Serially Connected Helical Magneto-Cumulative Generators (병렬 또는 직렬로 결합한 나선형 자장압축발전기의 출력특성 분석)

  • Kuk Jeong-Hyeon;Lee Heung-Ho
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.53 no.11
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    • pp.647-657
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    • 2004
  • Helical magneto-cumulative generator(HMCG)s are very useful devices in suppling pulsed high current to inductance loads. To apply fast high voltage pulses to high impedance loads, high current outputs of HMCGs are required to be conditioned to higher voltages by using various pulse components such as opening/closing switches and pulse transformer. In this paper, stepping with the trends of requirements for ever-increasing energy in pulsed power applications coupling methods is investigated to obtain higher output energy by connecting several HMCGs in series or parallel way. The coil dimension of HMCGs used in series or parallel connections was 50 mm in diameter and 150 mm in length. The coil was fabricated by using enamel-coated copper wire of 1 mm in diameter. The highest energy amplification ratio and peak voltage of load were achieved from the serially connected four-barrel HMCG system. They were 68 and 34 kV, respectively, when the initial energy of 0.36 kJ was supplied into that system with the load of 0.4 μH. Within the tested range of inductance ratio, energy amplification ratio was found to be highly dependent on the inductance ratio of serial- and parallel-connected HMCG systems to load, which to be optimal around 500 was turned out. The experimental results showed that the output energy and voltage of load are controlled by connecting HMCGs in series or parallel.

A Study on ASM Pulsed Power Generator for Non-thermal Plasma Applications (저온 플라즈마 발생을 위한 ASM 방식의 펄스파워 발생장치에 관한 연구)

  • Yang, Chun-Suk;Chung, Yong-Ho;Kim, Han-Joon
    • Proceedings of the KIEE Conference
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    • pp.2035-2037
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    • 1999
  • This paper describes an ASM(All Solid-state Modulator) pulsed power generator for non-thermal plasma applications. The proposed generator can produce 20kV, 500A, 100ns pulses at repetition rates up to 10kHz, and it is composed of 30 series connections of power circuit card assembly which contains paralleled MOSFETs, MOSFET drivers, energy storage capacitors and specially designed 1:1 pulse transformer. Higher pulse voltages and currents can easily be obtained by increasing the numbers of series and parallel connections of power circuit card and MOSFETs, respectively. Component layouts are optimized to minimize the leakage inductance and the voltage spikes across switching devices. Especially it put emphasis on the over-current protection (including short circuit) for the reliable operation in real situations. Experimental results show that the proposed pulser is very efficient in air pollution control application and could be useful for other applications such as synthesis of nanosize powders and non-thermal food processing.

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Current Limiting Characteristics of Flux-lock Type Superconducting Fault Current Limiter Using YBCO Films by Serial and Parallel Combinations (자속구속형 한류기의 직병렬조합에 따른 전류제한특성)

  • Park, Hyoung-Min;Cho, Yong-Sun;Lee, Ju-Hyoung;Jung, Byung-Ik;Choi, Hyo-Sang;Choi, Myong-Ho
    • Proceedings of the KIEE Conference
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    • pp.87-88
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    • 2007
  • We investigated the current limiting characteristics of flux-lock type superconducting fault current limiter using YBCO films University, Gwangju health college. The flux-lock type SFCL consisted of the transformer with a primary winding and a secondary winding connected in parallel, and the superconducting element was connected with secondary winding in series or parallel. Serial and parallel connections of superconducting elements are necessary for the increase of voltage and current capacities when we intend to apply the flux-lock type SFCL.

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Analysis of Series and Parallel Operation Characteristics using Physical Models of Power Devices (물리적인 전력소자 모델을 이용한 직$\cdot$병렬운전 특성 해석)

  • Yoon, Jae-Hak;Park, Gun-Tae
    • Proceedings of the KIPE Conference
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    • pp.213-217
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    • 2002
  • Power devices for high power drivers that need high switching speed (IGCT, HVIGBT) have been continuously developed. However, serial and parallel connections using several much cheaper, lower power capacity of devices than an expensive high power device are very useful methods in the aspect of cost down and high power application. Even the current and voltage unbalance problem is occurred at each devices. This unbalance characteristics are mainly caused by the differences of physical characteristics of each devices and the line inductance (stray inductance) of bus bars that consist of current path. This paper deals simulation analysis of serial connection of IGCTs and parallel connection of IGCTs using physical model of devices. And also, introduces the method to reduce the voltage and current unbalance problem.

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Numerical Analysis of Si-based Photovoltaic Modules with Different Interconnection Methods

  • Park, Chihong;Yoon, Nari;Min, Yong-Ki;Ko, Jae-Woo;Lim, Jong-Rok;Jang, Dong-Sik;Ahn, Jae-Hyun;Ahn, Hyungkeun
    • Transactions on Electrical and Electronic Materials
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    • v.15 no.2
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    • pp.103-111
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    • 2014
  • This paper investigates the output powers of PV modules by predicting three unknown parameters: reverse saturation current, and series and shunt resistances. A theoretical model using the non-uniform physical parameters of solar cells, including the temperature coefficients, voltage, current, series and shunt resistances, is proposed to obtain the I-V characteristics of PV modules. The solar irradiation effect is included in the model to improve the accuracy of the output power. Analytical and Newton methods are implemented in MATLAB to calculate a module output. Experimental data of the non-uniform solar cells for both serial and parallel connections are used to extend the implementation of the model based on the I-V equation of the equivalent circuit of the cells and to extend the application of the model to m by n modules configuration. Moreover, the theoretical model incorporates, for the first time, the variations of series and shunt resistances, reverse saturation current and irradiation for easy implementation in real power generation. Finally, this model can be useful in predicting the degradation of a PV system because of evaluating the variations of series and shunt resistances, which are critical in the reliability analysis of PV power generation.

Analysis of extended end plate connection equipped with SMA bolts using component method

  • Toghroli, Ali;Nasirianfar, Mohammad Sadegh;Shariati, Ali;Khorami, Majid;Paknahad, Masoud;Ahmadi, Masoud;Gharehaghaj, Behnam;Zandi, Yousef
    • Steel and Composite Structures
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    • v.36 no.2
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    • pp.213-228
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    • 2020
  • Shape Memory Alloys (SMAs) are new materials used in various fields of science and engineering, one of which is civil engineering. Owing to their distinguished capabilities such as super elasticity, energy dissipation, and tolerating cyclic deformations, these materials have been of interest to engineers. On the other hand, the connections of a steel structure are of paramount importance because of their vulnerabilities during an earthquake. Therefore, it is indispensable to find approaches to augment the efficiency and safety of the connection. This research investigates the behavior of steel connections with extended end plates equipped hybridly with 8 rows of high strength bolts as well as Nitinol superelastic SMA bolts. The connections are studied using component method in dual form. In this method, the components affecting the connections behavior, such as beam flange, beam web, column web, extended end plate, and bolts are considered as parallel and series springs according to the Euro-Code3. Then, the nonlinear force- displacement response of the connection is presented in the form of moment-rotation curve. The results obtained from this survey demonstrate that the connection has ductility, in addition to its high strength, due to high ductility of SMA bolts.

Analysis of Electrical Features of Serially and Parallelly connected Memristor Circuits (직렬 및 병렬연결 멤리스터 회로의 전기적 특성 해석)

  • Budhathoki, Ram Kaji;Sah, Maheshwar Pd.;Kim, Ju-Hong;Kim, Hyong-Suk
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.49 no.5
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    • pp.1-9
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    • 2012
  • Memristor which is known as fourth basic circuit element has been developed recently but its electrical characteristics are not still fully understood. Memristor has the incremental and decremental feature of the resistance depending upon the connected polarities. Also, its operational behavior become diverse depending on its connection topologies. In this work, electrical characteristics of diverse types of serial and parallel connections are investigated using the HP $TiO_2$ model. The characteristics are analyzed with pinched hystersis loops on the V-I plane when sine input signal is applied. The results of the work would be utilized usefully for analyzing the characteristics of memristor element and applications to logic circuit and neuron cells.