• Title/Summary/Keyword: Series and parallel connection

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Analysis of the Charging Characteristics of High Voltage Capacitor Chargers Considering the Transformer Stray Capacitance

  • Lee, Byungha;Cha, Hanju
    • Journal of Power Electronics
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    • v.13 no.3
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    • pp.329-338
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    • 2013
  • In this paper, the charging characteristics of series resonant type high voltage capacitor chargers considering the transformer stray capacitance have been studied. The principles of operation for the four operational modes and the mode changes for the four different switching frequency sections are explained and analyzed in the range of switching frequency below the resonant frequency. It is confirmed that the average charging currents derived from the above analysis results have non-linear characteristics in each of the four modes. The resonant current, resonant voltage, charging current, and charging time of this capacitor charger as variations of the switching frequency, series parallel capacitance ratio ($k=C_p/C_s$), and output voltage are calculated. From the calculation results, the advantages and disadvantages arising from the parallel connection of this stray capacitance are described. Some methods to minimize charging time of this capacitor charger are suggested. In addition, the results of a comparative test using two transformers whose stray capacitances are different are described. A 1.8 kJ/s prototype capacitor charger is assembled with a TI28335 DSP controller and a 40 kJ, 7 kV capacitor. The analysis results are verified by the experiment.

An analysis on the characteristics of superheater organization of ORC system for marine waste heat recovery system(WHRS) (선박폐열회수(WHRS) ORC 시스템의 과열기 구성에 따른 특성 해석)

  • Kim, Jong-Kwon;Kim, You-Taek;Kang, Ho-Keun
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.1
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    • pp.8-14
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    • 2014
  • This research designed Waste Heat Recovery System(WHRS) generation system of 250kW whose working fluid is R-245fa and studied on cycle characteristics by superheater organization. It simulated two conditions; series connection and parallel connection between superheater and evaporator. In simulation of series connection of superheater and evaporator, output of 4.7% could be improved because of the increase of enthalpy by overheating of working fluid. When setting 250kW for target output, cycle flux could be reduced by 4.1%. When setting 250kW as a target output of cycle In parallel connection simulation of superheater and evaporator, cycle flux was reduced as flux of heat source fluid for superheater was increased. So, the maximum 7.9% of working fluid pump's electric power was reduced and there was no big change in cycle efficiency and net efficiency by flux ratio.

Development of Boost Chopper with Built New Renewable Energy in Grid-Connected Distributed Power System (승압 초퍼 기능이 내장된 새로운 태양광 발전용 파워컨디셔너의 개발)

  • Mun, Sang-Pil;Lee, Su-Haeng;Kim, Young-Mun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.63 no.4
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    • pp.361-367
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    • 2014
  • This paper is related to a new solar power conditioner for a built-in step-up chopper function. In the first step-up chopper proposed solar PV power conditioner for mutually connected in series with the input voltage of the bypass diodes are respectively connected to the positive terminal should install the mutual boosting chopper diode connected in series with the boost chopper switching element between the two power supply and at the same time the first and the second was connected to a second diode and a resonance inductor and a snubber capacitor in series with each other. And the common connection point between the bypass diode and the step-up chopper and the step-up chopper diode common connection point of the switching elements of the input voltage was set to the boost inductor for storing energy. In addition, between the step-up chopper and the step-up chopper diode and a switching element of a joint connection point of the first auxiliary diode and the second common connection point of the auxiliary diode was provided, the resonance capacitor. Between the step-up chopper and the step-up chopper diode and a switching element of a joint connection point and the common connection point of the resonance inductor snubber capacitor and connecting the third secondary diode, between two power supply lines is characterized by configuring the DC link capacitor bus lines in parallel. Therefore, it is possible to suppress the switching loss through, DC link bus lines, as well as there could seek miniaturization and weight reduction of the power conditioner itself by using a common capacitor of the non-polar non-polar electrolytic capacitor having a capacitor, the service life of the circuit can be extended and it is possible to greatly reduce the loss can be greatly improve the reliability of the product and the operation of the product itself.

PV Module Configuration Considering Environment Conditions of Photovoltaic System (태양광 발전시스템의 환경조건을 고려한 PV 모듈 구성)

  • Ko, Jae-Sub;Chung, Dong-Hwa
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.2
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    • pp.31-41
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    • 2014
  • This paper proposes the configuration of photovoltaic(PV) module considering the environment conditions of the PV system. The PV system is consisted of the series-parallel connection of the PV module. When shadows or changes of the radiation or an electrical characteristic in the solar cell are happened to PV system, the serious power loss will occur. If the PV module connected in series has the shadows, the output current is restricted to current of shaded PV module. Also if shadow is occurred to the parallel connection PV module, the output voltage is limited to voltage of shaded PV module. These problems are caused power loss. Therefore, this paper proposes the method that makes the output power of the PV module equalize by reconfiguration of PV module using the switching considering these environment conditions. A validity of the method proposed in this paper proves through comparing with performance of conventional PV module.

A study on topology of the DeNOx, DeSOx using magnetic pulse compressors (가포화 자기스위치를 이용한 탈황탈질 시스템의 전원장치에 관한 연구)

  • Kim, Soo-Hong;Lee, Young-Duck;Kim, Seung-Mo;Kim, Byung-Sub;Kwon, Byung-Ki;Choi, Chang-Ho
    • Proceedings of the KIPE Conference
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    • 2008.06a
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    • pp.157-159
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    • 2008
  • Generally, Capacitor charging power supply (CCPS) consist of the full-bridge inverter, LC resonant tank and capacitance load. The multi-connection systems are normally used for high voltage or high power application. In this paper, conventional parallel operation resonant type and proposed series operation PWM type CCPS for pulse corona occurrence of DeSOx, DeNOx system using magnetic pulse compressor make a comparison. The effect of proposed CCPS is verified by circuit characteristics analysis of parallel operation resonant type and series operation PWM type, and it is confirmed by simulation result.

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Characteristics of 15 kVA superconducting fault current limiter (15 kVA급 저항형 초전도 한류기의 전류제한특성)

  • Choi, Hyo-Sang;Kim, Hye-Rim;Hwang, Si-Dole;Kim, Sang-Joon;Lim, Hae-Ryong;Kim, In-Seon;Hyun, Ok-Bae
    • 한국초전도학회:학술대회논문집
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    • v.10
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    • pp.272-275
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    • 2000
  • We investigated a resistive superconducting fault current limiter (SFCL) fabricated using YBCO thin films on 2-inch diameter sapphire substrates. Nearly identical SFCL units were prepared and tested. The units were connected in series and parallel to increase the current and voltage ratings. A serial connection of the units showed significantly unbalanced power dissipation between the units. This imbalance was removed by introducing a shunt resistor to the firstly quenched unit. Parallel connection of the units increased the current rating. An SFCL module of 4 units in parallel, each of which has minimum quench current 25 Ap, was produced and successfully tested at a 220 V circuit. From the resistance increase, we estimated that the film temperature increases to 200 K in 5 msec, and 300 K in 120 msec. Successive quenches revealed that this system is stable without degradation in the current limiting capability under such thermal shocks as quenches at 220 V.

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Vibration Analysis of Planar Cable-Driven Parallel Robot Configurations (평면형 케이블 구동 병렬로봇의 구조에 따른 진동분석)

  • Piao, Jinlong;Jung, Jinwoo;Jin, Xuejun;Park, Sukho;Park, Jong-Oh;Ko, Seong Young
    • The Journal of Korea Robotics Society
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    • v.11 no.2
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    • pp.73-82
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    • 2016
  • This paper focuses on the vibration analysis of planar cable-driven parallel robots on their configurations. Despite of many advantages of the cable robots, elasticity of the cables may cause the vibration at the existence of external disturbance, resulting in deterioration of positioning accuracy. According to the vibration theory, having high first order natural frequency can prevent resonance with low frequency disturbance from the surrounding environment. A series of simulations showed that choosing frame / end-effector shape and cable connection method affects robots' natural frequency. For the precise simulation, the cables are modeled as linear springs and axial vibration of cables is mainly considered. Aspect ratios of the frame and end-effector are defined as non-dimensional parameters while their areas are fixed. It was shown that vibration analysis guides to design a planar cable robot in terms of high capacity to reduce vibration.

Design of Modular DC / DC Converter with Phase-Shifting Topology (위상천이 방식의 모듈형 DC/DC 컨버터 설계)

  • Chai, Yong-Yoong
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.1
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    • pp.81-86
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    • 2019
  • This paper is concerned with a system design that enables a the plurality of switching mode power supplies to be supplied with larger power through a parallel connection. For this purpose, a shunt resistor is placed in series at the output of the constant voltage regulator and the output voltage is sensed and controlled using an arduino. In this paper, two constant-voltage regulators were used for the experiment, but it is possible to generalize for more boards. By using the method that controls the system, the sum of the currents delivered by the two systems to the load was found to be 96% of the current drawn from each board. In case of efficiency, 92.4% efficiency is achieved in the unit board and the efficiency in parallel connection is about 90%.

Study on the Effect of Membrane Module Configuration on Pervaporative Performance through Model Simulation (모델모사를 이용한 막모듈 연결 및 배열이 투과증발 막성능에 끼치는 영향에 관한 연구)

  • Yeom, Choong-Kyun;Yoon, Seok-Bok;Park, You-In
    • Membrane Journal
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    • v.18 no.4
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    • pp.294-305
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    • 2008
  • This study was focused on the investigation of the effects of membrane module configuration and the temperature of feed retentate flowing along with module length on membrane performance through model simulation. A simulation model of pervaporative dehydration through membrane module assemble in which a number of unit modules are connected in parallel or in series has been established. In this study, ethanol/water mixture was used as model mixture. Some of permeation parameters in the model were quantified directly from the real dehydration pervaporation of ethanol through a lab-made membrane. By adopting the coefficients determined empirically the simulation model could be of more practical value. The simulation of pervaporation with two basic module configurations, that is, parallel connection and series connection, could present the importance of process parameters such as feed rate, module connection mode, number of stages, and inter-stage heating.

AC/DC Resonant Converter to Control for DC Arc furnace (직류 전기아크로를 제어하기 위한 전원장치로서의 AC/DC 공진형 컨버터)

  • ;;Jaan Jarvik
    • The Transactions of the Korean Institute of Power Electronics
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    • v.8 no.1
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    • pp.1-8
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    • 2003
  • When solving the problems of electric power quality the converters with high Power factor are useful for the DC arc furnace power supply. In this paper, resonant converters of 50(60) Hz AC to DC arc described, where in each period of network voltage the capacitor and inductor of an oscillatory circuit are switched from series into parallel and vice versa parametrically. The duration of series and parallel connection and also the transformation ratio are dependent on load. Parallel oscillatory circuit restricts the short circuit current. These converters have high power factor from no-load to short-circuit and fit very well to supply are furnaces.