• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권6호
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• pp.396-401
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• 2004

Single phase induction motor(SPIM) is one of the most widely used type of low power AC motors in the world, especially for domestic or commercial applications where a three phase power supply is not available. Single phase induction motors have no starting torque their own. So there are several ways of starting single phase induction motors. The most common type is the starting capacitor installed in series with the auxiliary winding to increase the starting torque. In the conventional systems, this function is conducted by a centrifugal switch. But the mechanical centrifugal switch has many problems such as switch malfunction. This paper presents the auxiliary winding control using digital universal starting switch to overcome these shortcomings of centrifugal switch.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.663-667
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• 1998

This paper describes for reducing harmonic distortion on CO2 welding machine with nonlinear load characteristic using single-switch three-phase AC/DC converter. The low-order harmonic component amplitude of the phase current of single-switch three-phase discontinuous mode is calculated. Experimental results show that CO2 welding machine with single-switch three-phase AC/DC converter is effectively controlled with power factor correction for phase current during welding time.

• Journal of Power Electronics
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• 제8권1호
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• pp.51-59
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• 2008

This paper addresses several issues concerning the analysis, design, modeling, simulation and development of single-phase, single-switch, power factor corrected AC-DC high frequency switching converter topologies with transformer isolation. A detailed analysis and design is presented for single-switch topologies, namely forward buck, flyback, Cuk, Sepic and Zeta buck-boost converters, with high frequency isolation for discontinuous conduction modes (DCM) of operation. With an awareness of modem design trends towards improved performance, these switching converters are designed for low power rating and low output voltage, typically 20.25W with 13.5V in DCM operation. Laboratory prototypes of the proposed single-switch converters in DCM operation are developed and test results are presented to validate the proposed design and developed model of the system.

• Journal of Power Electronics
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• 제7권4호
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• pp.318-327
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• 2007

The design and performance analysis of a power factor corrected (PFC), single-phase, single switch flyback buck-boost ac-dc converter is carried out for low power battery charging applications. The proposed configuration of the flyback buck-boost ac-dc converter consists of only one switch and operates in discontinuous current mode (DCM), resulting in simplicity in design and manufacturing and reduction in input current total harmonic distortion (THD). The design procedure of the flyback buck-boost ac-dc converter is presented for the battery charging application. To verify and investigate the design and performance, a simulation study of the flyback buck-boost converter in DCM is performed using the PSIM6.0 platform. A laboratory prototype of the proposed single switch flyback buck-boost ac-dc converter is developed and test results are presented to validate the design and developed model of the system.

• 조명전기설비학회논문지
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• 제19권7호
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• pp.60-66
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• 2005

본 연구에서는 단일전력단 Two-Switch Forward 컨버터에 관하여 논하였다. 최근 국제적으로 제정된 ICE 61000-3-2와 IEEE 519같은 규정에서 입력 전류에 대한 고조파 규제가 강화되면서 전원 공급 장치의 역률개선 회로가 필수적으로 되었다. 따라서 본 연구에서는 저전압 대전류 출력에 적합한 방안으로 단일전력단 Two-Switch Forward 컨버터 회로를 제안하고, 모드별 동작, 특성 및 설계에 관하여 논하였으며, MOSFET를 사용하여 200[W](5[V], 40[A])급 시작품을 제작, 100[kHz]에서 실험하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1292-1295
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• 2000

In this paper, we proposed a new single-stage single-switch power factor correction(S-4 PFC) converter with output electrical isolation. The configuration of this converter is achieved by combining a fly back circuit and a forward circuit in one power stage. To verify the theoretical analysis of the proposed converter, a design example is given with its Pspice simu-lation and experimental results.

• Journal of electromagnetic engineering and science
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• 제14권4호
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• pp.411-414
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• 2014

A switch is one of the most useful circuits for controlling the path of signal transmission. It can be added to digital circuits to create a kind of gate-level device and it can also save information into memory. In RF subsystems, a switch is used in a different way than its general role in digital circuits. The most important characteristic to consider when designing an RF switch is keeping the isolation as high as possible while also keeping insertion loss as low as possible. For high isolation, we propose leakage signal cancellation and inductive switching for designing a singlepole double-throw (SPDT) RF switch. By using the proposed method, an isolation level of more than 23 dB can be achieved. Furthermore, the heterojunction bipolar transistor (HBT) process is used in the RF switch design to keep the insertion loss low. It is demonstrated that the proposed RF switch has an insertion loss of less than 2 dB. The RF switch operates from 1 to 8 GHz based on the $0.18-{\mu}m$ SiGe HBT process, taking up an area of $0.3mm^2$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.267-270
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• 2002

Fractional horse power single phase induction motors have no starting torque their own. So there are several ways of starting single phase induction motors. The most common type is the starting capacitor installed in series with the auxiliary winding to increase the starting torque. Also, the auxiliary winding is disconnected once the speed of the motor reaches 70 to 80 [%] of the rated speed. In the conventional systems, this function is conducted by a centrifugal switch. But the mechanical centrifugal switch has many problems such as switch malfunction. This paper presents the new methods of electronic starting switch by inductor to overcome these shortcomings of centrifugal switch.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.252-257
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• 1998

Two-stage power factor correction (PFC) converter with a single PWM controller for universal input voltage (90-264V) is proposed. It consists of a power factor pre-regulator cascaded by a DC/DC converter as in a conventional two-stage approach. However, a single PWM controller is used as in a single-stage, single-switch PFC approach. The switch in the PFC part is synchronized with the switch in the DC/DC converter with a fixed switching frequency. Employing an adaptive delay scheme the switch in the PFC part is controlled to limit the energy storage capacitor voltage within a designed range for the optimum efficiency, and to reduce input current harmonic distortion. The experimental results obtained on a 200W (5V/40A) prototype PFC converter are given to verify the effectiveness of the proposed control method.

• 전력전자학회논문지
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• 제11권4호
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• pp.361-370
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• 2006

단일단 단일스위치 통기정류기형 플라이백 컨버터를 제안한다. 제안된 단일단 단일스위치에 의해 역률이 개선되었으며 IEC 61000-3-2의 고조파 전류 요구조건을 만족한다. Flyback 컨버터의 경우 2 차 측 정류용 다이오드로 사용되는 쇼트키 다이오드의 전압 강하에 의한 전력손실이 크며, 이러한 전력 손실을 줄이기 위해 정류용 다이오드를 대신하여 도통 저항이 작은 MOSFET을 사용함으로써 전력손실을 줄일 수 있으며 이를 동기정류기 (SR : Synchronous Rectifier)라 한다. 제안된 동기 정류기는 MOSFET의 드레인 소스간의 전압 강하를 이용하여 동작하는 VDSR(Voltage Driven Synchronous Rectifier)이며 효율 향상을 목적으로 한다. 본 논문에서 제안한 단일단 단일스위치 동기정류기형 플라이백 컨버터는 출력 전력 85W (l2V /7.1A)에 적용되었으며 실험결과를 통해 확인할 수 있다.