• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.1041-1044
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• 1992

A solar cell should be operated at the maximum output point on the I-V characteristic curve with constant current and constant voltage in order that the solar energy be fully utilized. According to, in this paper, we describes a controller which can track the maximum power point of a solar arry using current and voltage ripple variation of step up chopper system. The control circuit is desinged such that actual current and voltage are sensed directly from the solar cell array. These two signal are then holded sampling and multiplies by a single chip multiplier.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.1038-1040
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• 1992

Booster is used widely as one of the step-up DC/DC power converter in power conversion process for fuel cell power plant which have the electrical characteristic of the high current density and low cell voltage. In view of control system, booster can be unstable when it is operated in broad operation range because the transfer function of booster has zero in right half plane of s-domain. So for reliable operation, controller must make the system stable in whole working range. In this paper, the two control method such as digital PID control and fuzzy control is studied for booster output voltage regulation in fuel cell plant. The design procedure of PID control and fuzzy control is described. And the experiment of designed controller action is performed in various operation points for controller performance test.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.1032-1034
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• 2001

As well known, a solar cell has an optimal operating point to be able to get the maximum power $P_{max}$. So, many $P_{max}$ tracking controllers using the line voltage of a solar cell have been popularly used. But it may vary depending on the miss match between the solar cell output and the load. In this paper, we investigate the possibilities of $P_{max}$ control using the current tracking controller and the output voltage and the output current instead of the solar cell output power. And we also examine about the optimal power converter using ZVCS step up and down chopper circuit to operate the solar cell at an optimal voltage using these variables. And then, we show some experimental results to confirm the successful operation.

• 반도체디스플레이기술학회지
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• 제12권4호
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• pp.27-32
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• 2013

In this paper, the boost converter was implemented by digital control in many applications of the step-up. The PWM(pulse width modulation) control module of boost converter was digitized at power converter using the FPGA device and VHDL. The boost converter was designed to output a fixed voltage through the PI control algorithm of the PWM control module even if input voltage and output load are variable. The boost converter was digitized can be simplified by reducing the size of the module and the external control components. Thus, the digital power IC has advantageous for weight reduction and miniaturization of electronic products because it can be controlled remotely by setting the desired output voltage and PWM control module. The boost converter using the digital power IC was confirmed through experiments and the good performances were showed from experiment results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.357-358
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• 2010

An interleaved operation of isolated boost converter system has become a very attractive solution in order to convert from low input voltage (30 ~ 50V) of distributed power sources such as photovoltaic and fuel cells to high output voltage (380V/760V) required in grid-connected power conversion applications. In this paper, we have proposed zero voltage transition(ZVT) interleaved boost converter using a single resonant inductor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.696-698
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• 2000

A new high voltage generator is designed and basic performance analysis by 2D-FEA is performed. The new generator is able to supply electricity directly to the high voltage grid without the need for a step-up transformer. For the 2D-FEA analysis, the generator model is coupled to external circuit components with inductance and end-winding resistance.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.327-330
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• 1999

In this paper, the electrical characteristics of λ vibration-mode piezoelectric transformer for applying to CCFL driving inverter was investigated. Piezoelectric transformer was made of PZT - PMN -0.5wt% N $b_2$ $O_{5}$ composition. As a results of the electrical characteristics of piezoelectric transformer, when applied voltage was 35[ $V_{rms}$] in 100[k$\Omega$] load resistance, output voltage was about 510[ $V_{rms}$] and output power was more than 2[W]. As output power increased, step-up ratio and temperature was very stable until output power was 2.5(W). Also, Efficiency was maximum in 70[k$\Omega$] load resistance, and about 89[%]. Also, when piezoelectric transformer was continuously driven for 10[hrs], output voltage and temperature change ratio was fess than 10[%], and very stable. Conclusively, piezoelectric transformer fabricated in this paper can be applied to piezoelectric inverter for CCFL driving.g.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.351-354
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• 2006

Recently, a fuel cell with low voltage and high current output characteristics is remarkable for new generation system It needs both a DC-DC step-up converter and DC-AC inverter to be used in fuel cell generation system Therefor, this paper, consists of an isolated DC -DC converter to boost the fuel cell voltage 380[$V_{DC}$] and a PWM inverter with LC filter to convent the DC voltage to single phase 220[$V_{AC}$]. Expressly, a tapped inductor filter with freewheeling diode is newly implemented in the output filter of the proposed high frequency isolated ZVZCS PWM DC-DC converter to suppress circulating current under the wide output voltage regulation range, thus to eliminate the switching and transformer turn-on/off over-short voltage or transient phenomena Besides the efficiency of 93-97[%]is obtained over the wide output voltage regulation ranges and load variations.

• 전자공학회논문지SC
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• 제43권2호
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• pp.33-39
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• 2006

본 논문에서는 휴대용 적외선 야시경의 소형 경량화 및 저전력을 위한 전자회로부를 설계하였다. 설계한 전자회로부는 전압자동변환부와 전원공급부로 구성한다. 전압자동변환부는 배터리, 스위치부, 승압부, 전압선택부 등으로 구성한다. 전원공급부는 고광원 감지회로, 배터리 전압감지회로, 적외선 발광회로, 연결감지회로, 공급제어회로 등으로 구성한다. 설계한 전자회로부의 성능은 AN/PVS-14에 비하여 소모전력 및 상온 연속사용 시간에서 우수하였다.

• 센서학회지
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• 제13권5호
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• pp.363-368
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• 2004

A reliable voltage measurement system is necessary to monitor status of power facilities in substations, which is easy to set up and is not influenced by electromagnetic interference in and around substation. In this paper, we described a voltage measurement system (VMS) which is composed of a capacitive voltage probe, an impedance converter, and an optical linker. To get a wide-band characteristic of the VMS, a high speed impedance converter was used, and the output impedance of the VMS was set at $50{\Omega}$ to match any types of observing instruments. The frequency bandwidth of the VMS. which was estimated by a step pulse, was ranges from 11.42 Hz to 13.65 MHz, and the VMS showed a good response characteristic in a high frequency domain such as impulse voltages as well as a commercial frequency voltage.