• Journal of Power Electronics
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• v.6 no.4
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• pp.356-365
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• 2006

This paper presents an improved three-phase PFC power rectifier with a three-phase diode rectifier cascaded four-switch boost converter. Its operating principle contains the operating principle of two conventional three-phase PFC power rectifiers: one switch boost converter type and a two switch boost converter type. The operating characteristics of the four switch boost converter type three-phase PFC power rectifier are evaluated from a practical point of view, being compared with one switch boost converter type and two switch boost converter topologies.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.1
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• pp.90-94
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• 2013

A low loss power dividing switch in a indoor microwave power distribution system is proposed and designed with a various power dividing ratio. Switching characteristics are analyzed by use of the S-parameter of the switch. Newly proposed switch showed a very low return loss less than -30dB at the operating frequency of 2.45GHz. Three kinds of the switch in which we take out individually 1/2, 1/3 and 1/4 of the input power were fabricated, and measured the delivered, transmitted, and return loss power ratio. Simulated results showed that the lower power ratio is, the better accurate operating performance shows. This switch can switch the input power from 4.5% to 58% with the variance of 5% output power. The experimental results are in good agreement with the simulation within the return loss of 1%.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.10
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• pp.120-125
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• 2006

In contrast to the conventional trigatron switch in which the currents are constricted by the z-pinch mechanical the new switch operates in an inverse pinch geometry formed by a pair of spiral electrodes in a sealed-off type. Inverse pinch switch greatly reduces hot spot formations and protects the electrode surfaces. The switch can be initiated with an electrical trigger electrode. Advantages of the new switch over the conventional switches are longer useful life, high current capability and lower inductance due to the dispersed and moving current sheet. These improved characteristics may make the inverse pinch switch suitable for pulse power systems.

• 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.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.4
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• pp.366-373
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• 2011

The magnetic switch used in pulsed-power applications is superior in its high repetition rate, high stability, and long lifetime. But magnetic switch was optimized switching operation by manual control. When the load changes, the switching state can not be optimized automatically. In this paper, the auto control method of magnetic switch for high pulsed-power proposed. The magnetic switch is used capacitor charging power supply for high-voltage compressor. The proposed method can be optimized an efficiency of the system by magnetic switch auto control according to load variation. And the proposed method verify the experimental results.

• 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.

• Journal of Korean Institute of Industrial Engineers
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• v.26 no.2
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• pp.136-145
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• 2000

The objective of this study is to evaluate the human performance relating to the layouts of the two different hand switch types with two and three buttons in the nuclear power plants. Using a computer simulation, the cognitive performance for the hand switch layouts was measured on the basis of response and task completion times. Comparative analyses were performed with three different layouts representing the current switch arrangements in the Yonggwang nuclear plants 5 and 6 and Ulchin 3 and 4, respectively. Statistical analyses revealed that the performance of the two-buttoned switch layouts was found to be better than those of the three-buttoned switch. Furthermore, the superiority of the two-buttoned switch type is consistent regardless of various layout types. These results imply that the difference of the cognitive performance can be attributable to the switch types rather than to the switch layouts. Therefore, from the cognitive perspective, the two-buttoned switch type is recommended for future power nuclear plants.

• Journal of Power Electronics
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• v.16 no.2
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• pp.786-797
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• 2016

This paper describes the design and development of a novel semiconductor-based solid-state switch for damped oscillating voltage test system. The proposed switch is configured as two identical series-connected switch stacks, each of which comprising 10 series-connected IGBT function units. Each unit consists of one IGBT, a gate driver, and an auxiliary voltage sharing circuit. A single switch stack can block 20 kV-rated high voltage, and two stacks in series are proven applicable to 30 kV-rated high voltage. The turn-on speed of the switch is approximately 250 ns. A flyback topology-based power supply system with a front-end power factor correction is built for the drive circuit by loosely inductively coupling each unit with a ferrite core to the primary side of a power generator to obtain the advantages of galvanic isolation and compact size. After the simulation, measurement, and estimation of the parasitic effect on the gate driver, a prototype is assembled and tested under different operating regimes. Experimental results are presented to demonstrate the performance of the developed prototype.

• Journal of Power Electronics
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• v.1 no.2
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• pp.71-77
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• 2001

This paper proposes a new zero-current switching (ZCS) pulse-width modulation (PWM) switch cell that has no additional conduction loss of the main switch. In this cell, the main switch and the auxiliary switch turn on and turn off under zero current condition. The diodes commutate softly and the reverse recovery problems are alleviated. The conduction loss and the current stress of the main switch are minimized, since the resonating current stress of the main switch are minimized, since the resonating current for the soft switching does not flow through the main switch. Based on the proposed ZCS PWM switch cell, a new family of DC to DC PWM converters is derived. The new family of ZCS PWM converters is suitable for the high power applications employing IGBTs. Among the new family of DC to DB PWM converters, a boost converter was taken as an example and has been analyzed. Design guidelines with a design example are described and verified by experimental results from the 2.5 kW prototype converter operating at 40 kHz.

• Journal of Power Electronics
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• v.15 no.2
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• pp.497-503
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• 2015

This paper analyses the harmonic pollution to power grids caused by several high-power rectifiers, summarizes the requirements for rectifiers in suppressing grid-side current harmonics and optimizes a new-type of current source PWM rectifier with a hybrid switch. The rectifier with a hybrid switch boasts significant current characteristics and cost advantages in the high-power area. To further enhance the working frequency of the current source rectifier with a hybrid switch for suppressing grid-side harmonics and reducing the inductance size, this paper proposes an optimal control strategy based on space vector. It also verifies that the optimal control strategy based on space vector can reduce the total harmonic distortion of the grid-side current of the rectifier with a hybrid switch via circuit simulation and experimental results.