• 제목/요약/키워드: output capacitor voltage control

검색결과 226건 처리시간 0.024초

비대칭 전압 제어를 이용한 단상 임베디드 Z-소스 DC-AC 인버터 (A Single-Phase Embedded Z-Source DC-AC Inverter by Asymmetric Voltage Control)

  • 오승열;김세진;정영국;임영철
    • 전력전자학회논문지
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    • 제17권4호
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    • pp.306-314
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    • 2012
  • In case of the conventional DC-AC inverter using two DC-DC converters with unipolar output capacitor voltages, for generating the AC output voltage, the output capacitor voltages of its each DC-DC converter must be higher than the DC input voltage. To solve this problem, this paper proposes a single-phase DC-AC inverter using two embedded Z-source converters with bipolar output capacitor voltages. The proposed inverter is composed of two embedded Z-source converters with common DC source and output AC load. The AC output voltage is obtained by the difference of the output capacitor voltages of each converter. Though the output capacitor voltage of converter is relatively low compared to the conventional method, it can be obtained the same AC output voltage. Moreover, by controlling asymmetrically the output capacitor voltage, the AC output voltage of the proposed system is higher than the DC input voltage. To verify the validity of the proposed system, a DSP(TMS320F28335) based single-phase embedded Z-source DC-AC inverter was made and the PSIM simulation was performed under the condition of the DC source 38V. As controlled symmetrically and asymmetrically the output capacitor voltages of each converter, the proposed inverter could produce the AC output voltage with sinusoidal waveform. Particularly, in case of asymmetric control, a higher AC output voltage was obtained. Finally, the efficiency of the proposed system was measured as 95% and 97% respectively in case of symmetric and asymmetric control.

입력 직류 전압과 Z-네트워크 커패시터 전압 검출에 의한 Z-소스 인버터의 출력 전압 제어 (Output Voltage Control of Z-Source Inverter by the Detection of the Input DC Voltage and Z-Network Capacitor Voltage)

  • 김세진;정영국;임영철;최준호
    • 전기학회논문지
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    • 제60권8호
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    • pp.1515-1522
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    • 2011
  • This paper proposes the algorithm for the output AC voltage control of Z-source inverter by the detection of the input DC voltage and Z-network capacitor voltage. The actual modulation index of the proposed method is detected by the capacitor voltage in Z-network and input DC voltage of three-phase Z-source inverter. Control modulation index for the output voltage control is calculated by the detected actual modulation index and reference modulation index. And, calculated control modulation index is applied to the modified space vector modulation (SVM) for control the output voltage of Z-source inverter. To verify the validity of the proposed method, PSIM simulation was achieved and a DSP controlled 1[kW] three-phase Z-source inverter was producted. The simulation and experiment were performed under the condition that the load was changed in case of the constant input DC voltage and the input DC voltage was changed in case of the load was constant. As a result, we could know that the output phase voltage of Z-source inverter followed to the reference voltage 70[VRMS] despite the load or the input DC voltage were suddenly changed.

출력 커패시터가 없는 위상천이 풀브릿지 컨버터의 전류 전향 보상을 이용한 출력 전압 제어 기법 (Output Voltage Control Technique Using Current Forward Compensation for Phase Shifted Full Bridge Converter Without Output Capacitor)

  • 신유승;백승우;김학원;조관열;강정원
    • 전력전자학회논문지
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    • 제27권1호
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    • pp.40-47
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    • 2022
  • At present, the low-voltage, high-current type power supply is mainly used for effective sterilization in the ballast water treatment system. Research on PSFB converters without output capacitors has been ongoing. Such converters effectively treat ballast water without a separate disinfectant through electric pulses by applying a pulse-type power to the output electrode without an output capacitor. However, in the case of the pulse-type electrolysis treatment method, voltage overshoot can occur due to abrupt voltage fluctuations when the load changes, resulting in circuit reliability problems because of the output capacitorless system. Therefore, a new voltage control algorithm is required. In this paper, we will discuss voltage control for pulsed electrolysis topology without an output capacitor. The proposed voltage control method has been verified using Simulation and experiment. The usefulness of the proposed control method has been proven by the experimental results.

비선형 제어기법을 이용한 PWM 정류기의 입출력 제어 (Input and Output Control of PWM Rectifiers using a Nonlinear Control Technique)

  • 이동춘
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제48권12호
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    • pp.701-708
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    • 1999
  • The PWM rectifiers are capable of supplying sinusoidal current control and unity power factor control on the input side and dc output voltage control on the output side. By applying nonlinear control to the PWM rectifiers, the responses of input current and output voltage can be improved and due to fast voltage control the output electrolytic capacitor can be reduced remarkably. In addition, it is checked whether or not the current capacity of the reduced-size capacitor allows the ripple current of the rectifier. The nonlinear control technique gives a good performance for supply voltage disturbances. The validity of the proposed scheme has been verified by the experiment using DSP.

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Unified MPPT Control Strategy for Z-Source Inverter Based Photovoltaic Power Conversion Systems

  • Thangaprakash, Sengodan
    • Journal of Power Electronics
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    • 제12권1호
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    • pp.172-180
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    • 2012
  • Z-source inverters (ZSI) are used to realize both DC voltage boost and DC-AC inversion in single stage with a reduced number of power switching devices. A traditional MPPT control algorithm provides a shoot-through interval which should be inserted in the switching waveforms of the inverter to output the maximum power to the Z-network. At this instant, the voltage across the Z-source capacitor is equal to the output voltage of a PV array at the maximum power point (MPP). The control of the Z-source capacitor voltage beyond the MPP voltage of a PV array is not facilitated in traditional MPPT algorithms. This paper presents a unified MPPT control algorithm to simultaneously achieve MPPT as well as Z-source capacitor voltage control. Development and implementation of the proposed algorithm and a comparison with traditional results are discussed. The effectiveness of the proposed unified MPPT control strategy is implemented in Matlab/Simulink software and verified by experimental results.

7-레벨 PWM 인버터의 직렬 커패시터 입력전원의 전압균형제어 (Voltage Balancing Control of Input Voltage Source Employing Series-connected Capacitors in 7-level PWM Inverter)

  • 김진산;강필순
    • 전기학회논문지
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    • 제67권2호
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    • pp.209-215
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    • 2018
  • This paper present a 7-level PWM inverter adopting voltage balancing control to series-connected input capacitors. The prior proposed 7-level PWM inverter consists of dc input source, three series-connected capacitors, two bidirectional switch modules, and an H-bridge. This circuit topology is useful to increase the number of output voltage levels, however it fails to generate 7-level in output voltage without consideration for voltage balancing among series-connected capacitors. Capacitor voltage imbalance is caused on the different period between charging and discharging of capacitor. To solve this problem, we uses the amplitude modulation of carrier wave, which is used to produce the center output voltage level. To verify the validity of the proposed control method, we carried out computer-aided simulation and experiments using a prototype.

LED 정전류 구동회로의 입력전압 리플 크기에 의한 특성 비교 (Characteristic comparisons of the constant current LED driver by the ripple of the input voltage)

  • 박종연;전인웅;유진완;최영민
    • 산업기술연구
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    • 제32권A호
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    • pp.115-118
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    • 2012
  • Recently, there are a lot of papers in order to replace the electrolytic capacitor into the film capacitor in output of PFC(Power Factor Correction). However, the film capacitor, which has capacitance of low values, causes a large ripple voltage in output of PFC. The LED drivers are connected series in the output of PFC and affected by the magnitude of voltage ripple. In this paper, we have compared the fixed frequency method with the variable frequency for the constant-current control and propose the control method to avoid the sub-harmonic oscillation in the variable input voltage. An 80W PFC, using film capacitors instead of electrolytic capacitors, and LED driver has been built and compared the fixed frequency control method with the variable frequency control method.

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3상 임베디드 Z-소스 인버터 (Three Phase Embedded Z-Source Inverter)

  • 오승열;김세진;정영국;임영철
    • 전력전자학회논문지
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    • 제17권6호
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    • pp.486-494
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    • 2012
  • In this paper, we proposes the three-phase embedded Z-source inverter consisting of the three embedded Z-source converters and it's the output voltage control method. Each embedded Z-source converter can produce the bipolar output capacitor voltages according to duty ratio D such as single-phase PWM inverter. The output AC voltage of the proposed system is obtained as the difference in the output capacitor voltages of each converter, and the L-C output filter is not required. Because the output AC voltage can be stepped up and down, the boost DC converter in the conventional two-stage inverter is unnecessary. To confirm the validity of the proposed system, PSIM simulation and a DSP based experiment were performed under the condition of the input DC voltage 38V, load $100{\Omega}$, and switching frequency 30kHz. Each converter is connected by Y-connection for three-phase loads. In case that the output phase voltage is the same $38V_{peak}$ as the input DC voltage and is the 1.5 times($57V_{peak}$), the simulation and experimental results ; capacitor voltages, output phase voltages, output line voltages, inductor currents, and switch voltages were verified and discussed.

출력커패시터 내압 저감이 가능한 승압 컨버터 구조 (Circuit configuration of step-up converter with reduced working voltage of output capacitor)

  • 김선필;박성준;강필순
    • 전기전자학회논문지
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    • 제22권3호
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    • pp.630-637
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    • 2018
  • 모터제어장치(MCU)는 높은 전압을 공급하기 위해 인버터 앞 단에 승압용 컨버터를 사용한다. 승압 컨버터는 높은 출력전압을 생성하기 때문에 내압이 높은 출력 커패시터가 필요하여 커패시터의 비용이 증가하게 된다. 이를 해결하기 위해 출력 커패시터의 작동 전압을 낮출 수 있는 승압 컨버터 구조를 제시한다. 제안된 컨버터의 기본 특성은 기존의 부스트 컨버터와 유사하며, 출력 커패시터와 입력 배터리를 직렬로 연결하는 출력 단자의 구조적 차이가 있다. 이러한 출력단 회로 구조에 의해 출력 커패시터의 동작 전압은 기존 승압 컨버터 보다 낮아진다. 이론적 분석, 시뮬레이션, 실험을 통해 기존 부스트 컨버터와 비교하고 타당성과 성능을 검증한다.

넓은 출력전압 제어범위에서 동작하는 보조스위치 적용 공통커패시터 연결 LLC 공진컨버터 (A Common Capacitor Connected LLC Resonant Converter with Auxiliary Switches Operating Over a Wide Output Voltage Control Range)

  • 오재성;김민지;이지철;김은수;전용석;국윤상
    • 전력전자학회논문지
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    • 제24권4호
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    • pp.294-302
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    • 2019
  • A capacitor common connected LLC resonant converter with auxiliary switches for a wide output voltage control range is presented in this paper. The proposed converter can be controlled in two ways to achieve a wide output voltage control range of Vo-3Vo. The first control method is performed through pulse width modulation of the auxiliary switches and primary switching devices. The second control method is conducted through frequency modulation of the primary switching devices configured to operate in full-bridge switching modes, when the auxiliary switches are turned off. The feasibility of the proposed converter is verified by the experimental results of a 5 kW prototype.