• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.12
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• pp.36-46
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• 2008

This paper is to study on the Construction of Test circuit and Unification of Experiment Method for high voltage gas-insulated load switch using high power testing system The high power testing system is a equipment to verify electrical and mechanical performance on electrical product. The system consist of short-circuit generator, back-up breaker, making switch, impedance, high voltage transformer, low voltage transformer, measuring and protection system, etc. Using this system, we can test related to high power, for example, short-time current test, active load Current test, magnetizing Current test, capacitive current test, closed loop current test, etc. Standards of high voltage gas-insulated load switch that is in use domestic distribution line are ES 5925-0002, IEC 60265-1, IEC 62271-1 and IEEE C 37.74, etc. In this paper, we standardized on the test procedure, organization of test circuit and analysis of measured data prescribed many difference standards, and applied this test method to 600[MVA] high power testing system. So that we can test the load switch satisfied standards.

• Journal of Power Electronics
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• v.7 no.4
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• pp.301-309
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• 2007

The flyback converter is one of the most attractive isolated converters in small power applications because of its simple structure. However, it suffers from high device stress, large transformer size, and high voltage stress across its switch and diode. To solve these problems a new cost-effective PWM single-switch isolated converter is proposed. The proposed converter has no output filter inductor, reduced voltage stress on the secondary devices, and reduced transformer size. Moreover, the switch turn-off loss is reduced and no dissipative snubber across the secondary diode is required. Therefore, it features a simple structure, a low cost, and high efficiency. The operational principle and characteristics of the proposed converter are presented and compared with the flyback converter and then verified experimentally.

• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.108-113
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• 2021

In this paper, a totem pole PFC was structured in two methods with FET and diode for low-speed switch while GaN FET was used for high-speed switch. Internal power loss, power conversion efficiency and steady-state characteristics of the two methods were compared in the totem pole bridgeless PFC circuit which is widely applied in large-capacity and high-efficiency switching rectifier of 500W or more. In order to compare and confirm the steady-state characteristics under equal conditions, a 2kW class totem pole bridgeless PFC was constructed and the experimental results were analyzed. From the experimental results, it was confirmed that the low-speed switch operation has a large difference in efficiency due to the internal conduction loss of the low-speed switch at a low input voltage. Especially, input power factor and load characteristic showed no difference regardless of the low-speed switch operation.

• Journal of Power Electronics
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• v.12 no.6
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• pp.954-959
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• 2012

A hybrid switch that uses a microelectromechanical system (MEMS) switch as a gate driver of a MOSFET is applied to an energy harvesting system. The power management circuit adopting the hybrid switch provides ultralow leakage, self-referencing, and high current handling capability. Measurements show that solar energy harvester circuit utilizing the MEMS-MOSFET hybrid switch accumulates energy and charges a battery or drive a resistive load without any constant power supply and reference voltage. The leakage current during energy accumulation is less than 10 pA. The power management circuit adopting the proposed hybrid switch is believed to be an ideal solution to self-powered wireless sensor nodes in smart grid systems.

• Journal of Power Electronics
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• v.2 no.2
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• pp.104-111
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• 2002

This paper presents a new hybrid control scheme using Active-Clamped Class-E(ACCE) inverter for the Induction Heating (IH) jar. The proposed hybrid control scheme has characteristics, which acts as class-E inverter at lower switch voltage and ACCE inverter at higher switch voltage than reference voltage of the main switch by feeding back voltage of the switch. The proposedv hybrid control scheme also has advantage of conventional ACCE inverter such as Zero-Voltage-Switch(ZVS) of the main switch and the reduced switch voltage due to clamping cricuit. Moreover, the proposed hybrid control method using ACCE inverter has higher output power than convenional control scheme since ACCE inverter operates like class-E inverter at low input voltage condition. The principles of the proposed control are explained in detail and the validity of the proposed control scheme is verifed through the several interesting simulated and experimental results.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.230-231
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• 2012

This paper describes a gate driver that operates numerous semiconductor switch in the solide-state pulsed power modulator. the proposed gate driver is designed to receive both the isolated drive-power and the on/off pulse signals through the transformer. Moreover, the IGBT-switch can be quickly turned off by adding protection circuit. Therefore it protects the IGBT-switch from the arc condition that frequently occurs in high-voltage pulse application. To comprehend operating characteristic of each IGBT-switch in pulse output condition, the device consisting of a high efficiency soft-switching capacitor charger and two series stacking IGBT-switch is developed. Finally, the relability of the proposed gate driver and the device for its test are proved through PSpice simulation and experiments.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.247-250
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• 2006

This paper presents the single-stage High Power Factor TSFC(Two-Switch Forward Converter). Recently, due to growing concern about the harmonic pollution of power distribution systems and the adoption of standards such as ICE 61000-3-2 and IEEE 519, There is a need to reduce the harmonic contents of AC line currents of power supplies. This research proposed the single-stage two switch forward circuit for low voltage and high current output. The principle of operation, feature and design considerations are illustrated and verified through the experiment with a 200W(5V, 40A) 200kHz MOSFET based experimental circuit.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.169-172
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• 2006

This paper presents the single-stage High Power Factor AC/DC Two-Switch Forward Converter (TSFC). Recently, due to growing concern about the harmonic pollution of power distribution systems and the adoption of standards such as ICE 61000-3-2 and IEEE 519, There is a need to reduce the harmonic contents of AC line currents of power supplies. This research proposed the single-stage two switch forward circuit for low voltage and high current output. The principle of operation, feature and design considerations are illustrated and verified through the simulation with a 200W(5V, 40A) 200kHz MOSFET based experimental circuit.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.36-37
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• 2013

This paper presents high voltage operation sensing boost converter with high side current. Proposed topology has three functions which are high voltage driving, high side current sensing and low voltage boost controller. High voltage gate driving block provides LED dimming function and switch function such as a load switch of LED driver. To protect abnormal fault and burn out of LED bar, it is applied high side current sensing method with high voltage driver. This proposed configuration of boost converter shows the effectiveness capability to LED driver through measurement results.

• Journal of Power Electronics
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• v.14 no.1
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• pp.1-10
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• 2014

This paper proposes a high-efficiency supercapacitor charger. Conventional two-switch forward converter can be used for charging supercapacitors. However, the efficiency of conventional converters is low because of their switching losses. This study presents a high-efficiency two-switch forward converter for supercapacitor chargers. The proposed converter improves power efficiency by 4 %, from 89 % to 93 %. The proposed converter has the advantages of reduced switch voltage stresses and minimized circulating current when compared to other converter topologies. The performance of the proposed converter is evaluated by experimental results using a 300 W prototype circuit for a 54-V, 35-F supercapacitor bank.