• Title/Summary/Keyword: Static frequency converter

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RESEARCH STUDY ON THE COMPARSION OF TORQUE CONVERTER AND STATIC CONVERTER FOR GAS TURBINE POWER PLANT (복합 화력 발전소에서의 유체 토오크 컨버터와 전기식 가변속장치의 비교에 관한 연구)

  • Hur, Sung-Kwang;Rhew, Hong-Woo;Han, Kyung-Hie
    • Proceedings of the KIEE Conference
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    • 1993.07b
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    • pp.899-901
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    • 1993
  • LARGE SYNCHRONOUS GENERATORS USED IN CONNECTION WITH COMPRESSOR, TURBINE, IN MOST CASE, NEED THE HELP OF AN ELECTRICAL DRIVES FOR STARTING IN GAS TURBINES. NOWDAYS, THE STATIC FREQUENCE CONVERTER STARTING SYSTEM is EMPLOYED IN POWER PLANT. THIS PAPER DESCRIBES TORQUE CONVERTER, STATIC FREQUENCY CONVERTER AND COMPARSION OF TWO SYSTEMS.

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PWM-Based Sliding Mode Controller for Three-Level Full-Bridge DC-DC Converter that Eliminates Static Output Voltage Error

  • Liu, Jilong;Xiao, Fei;Ma, Weiming;Fan, Xuexin;Chen, Wei
    • Journal of Power Electronics
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    • v.15 no.2
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    • pp.378-388
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    • 2015
  • This paper proposes a pulse width modulation (PWM)-based sliding mode controller (SMC) for a full-bridge DC-DC converter that can eliminate static output voltage error. Hysteretic SMC in DC-DC converter does not have a fixed switching frequency, and applying hysteretic SMC to full-bridge converters is difficult. Fixed-frequency SMC, which is also called PWM-based SMC, based on equivalent control overcomes these shortcomings. However, the controller order reduction in equivalent control in PWM-based SMC causes static output voltage error. To resolve this issue, an integral item is added to the PWM-based SMC. Sliding mode coefficients are designed by applying a standard second-order system to the sliding mode surface. The effect of adding an integral item on the controller is analyzed, and an integral coefficient design method is proposed. Experiment results on a three-level full-bridge DC-DC converter verify the control scheme and design method proposed in this paper.

The Analysis of a High Frequency Series Resonant DC-DC Converter (고주파 직렬공진형 DC-DC Converter의 특성 해석)

  • 이윤종;김철진
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.9
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    • pp.934-943
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    • 1990
  • There are no turn-on losses in the series Resonant Converter which operates above the resonance frequency, and the commutation stress on the switched component is low. For a given Series Resonant Converter with specified load resistance, the output voltage is a function of the operation frequency. This paper describes the static and dynamic characteristic analysis of the Series Resonant DC to DC Converter, which is operating above the resonant frequency, with frequency control. For the analysis method, state plane technique is adopted, and the circuit operation is defined from normalized switching frequency, Fsn. Under this condition, circuit performance is analyzed ideally. The validity of the proposed analysis is verified by comparing with experimental results, the stability of the converter is confirmed against small variations around the operating point by conventional frequency domain analysis, and the stress quantity added to switch component is shown.

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The Analysis of a Series Resonant Converter with Frequency Control (주파수 제어에 의한 직렬 공진형 컨버터의 특성 해석)

  • 이윤종;김철진
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.6
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    • pp.557-567
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    • 1990
  • This paper describes the static and dynamic characteristic analysis of the Series Resonant DC to DC Converter with frequency control. The natural commutation of all switch element is realized when the switching frequency is below the resonant frequency of the tank circuit, and the analysis is limited to only this region. For the analysis method, state plane technique is adopted, and each operation mode is defined from normalized switching frequency Fsn. Under this condition, circuit performance is analyzed ideally. The physical characteristics of the series resonant converter is easily grasped by this analysis method with frequency control and this analytical results are directly applicable to the actual converter design. The validity of the analysis is verified by comparing with experimental results and the stability of the converter is confirmed against small variations around the operating point by conventional frequency domain analysis.

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Analog to Digital Converter for CMOS Image Sensor (CMOS Image Sensor에 사용 가능한 아날로그/디지탈 변환)

  • 노주영;윤진한;장철상;손상희
    • Proceedings of the IEEK Conference
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    • 2002.06b
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    • pp.137-140
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    • 2002
  • This paper is proposed a 8-bit anolog to digital converter for CMOS image sensor. A anolog to digital converter for CMOS image sensor is required function to control gain. Proposed anolog to digital converter is used frequency divider to control gain. At 3.3 Volt power supply, total static power dissipation is 8mW and programmable gain control range is 30dB. The gain control range can be easily increased with insertion of additional flip-flop at divided-by-N frequency divider circuit.

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Static Var Compensator Using Current Source PWM Converter (전류형 PWN 콘버어터의 희한 정지형 무효전력 보상장치에 관한연구)

  • 김철우;권순재;김광태
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.11
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    • pp.1183-1190
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    • 1990
  • In this paper, instantaneous reactive power compensation algorithm is proposed and analyzed. The static Var generator developed in this paper is the current source PWM converter using hysteresis comparator method, which compensates the reactive power by detecting each instantaneous phase voltage and line current, independently. Some aspects on the static Var compensator-such as inductance, capacitance, hysteresis width, and switching frequency, etc.-are discussed. The dynamic performances are examined through digital simulation and experimental test.

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An Analysis of the Noise Feature of a Static Frequency Converter (SFC) according to the Operation of a Gas Turbine (가스터빈 기동에 따른 정지형 주파수 변환장치(SFC:Static Frequency Converter)의 노이즈 특성 분석)

  • Jeong, Tae-Hoon;Choi, Sung-Wook;Kim, Hyeun-Soo
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.2025-2026
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    • 2008
  • This study aims to analyze the features of malfunction of an SFC that helps maintain the frequency of static rotation during the operation of a gas turbine in power plants where power generators and controllers have such a complicated structure as a nerve system, by using electric interference with peripheral devices and maintaining acquired data efficiently. Also, in order to track the possibility of malfunction by various surges and noises which may occur in the process of inserting an SFC during the operation of a gas turbine and to prepare protective measures for the possibility, the study intends to offer data for developing a surge protector suited to the features of a section that is supposed to incur the possibility of malfunction.

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A Study on the SCR Frequency Converter With a Rotating Distributor (회전접촉자를 사용한 SCR 주파수 변환기에 관한 연구)

  • Chung Yon Tack
    • 전기의세계
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    • v.24 no.1
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    • pp.43-53
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    • 1975
  • This paper describes a converter, which combines SCR bridge type rectifier circuit with a rotating distributor. This type of converter produces an adjustable low frequency output of three phase or single phase, from three phase or single phase power source. Output-waveforms of this converter are multi-pulse in three phase output, and square wave in single phase output. Problems about the operation of static switches, a commutation and output-waveforms are investigated, and experimental results verify that frequency can be adjusted satisfactorily from zero to 20 (Hz) and the expected output-waveforms are obtained without sparking on the distributor under various loading conditions. This converter can be utilized to low speed control of A.C. motors, and other lowfrequency loads.

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The Design of low voltage step-down DC-DC Converter with ESD protection device of low voltage triggering characteristics (저 전압 트리거형 ESD 보호회로를 탑재한 저 전압 Step-down DC-DC Converter 설계)

  • Yuk, Seung-Bum;Lee, KJae-Hyun;Koo, Yong-Seo
    • Journal of IKEEE
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    • v.10 no.2 s.19
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    • pp.149-155
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    • 2006
  • In this study, the design of low voltage DC-DC converter with low triggering ESD (Electro-Static Discharge) protection circuit was investigated. The purpose of this paper is design optimization for low voltage(2.5V to 5.5V input range) DC-DC converter using CMOS switch. In CMOS switch environment, a dominant loss component is not switching loss but conduction loss at 1.2MHz switching frequency. In this study a constant frequency PWM converter with synchronous rectifier is used. And zener Triggered SCR device to protect the ESD phenomenon was designed. This structure reduces the trigger voltage by making the zener junction between the lateral PNP and base of lateral NPN in SCR structure. The triggering voltage was simulated to 8V.

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Static Characteristics Analysis of PWM Cuk AC-AC Converter for Power Quality Improvement of Custom Power (Custom Power의 전력품질 향상을 위한 PWM Cuk AC-AC 컨버터의 정적 특성 해석)

  • 최남섭
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2004.05b
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    • pp.513-516
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    • 2004
  • In this paper, a PWM Cuk AC-AC converter for power quality improvement of custom power is presented. The PWM Cuk AC-AC converter that is used in VVCF applications such as AC line conditioner, phase shifter is modelled by using complex circuit DQ transformation whereby the static characteristics equations such as voltage gain and power factor is analytically obtained. Finally, the PSIM simulation show the validity of the modelling and analysis.

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