• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.249-252
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• 2002

Recently, the advanced countries are using the corrosion monitoring system in a chemical plant and an oil tank in order to protect the corrosion because it leads to a big accident, pollution of soil. and lose of money Generally. the owners of the facilities adopt CP(Cathodic Protection) systems to protect the corrosion also. However, a CP system for oil tank was not considered in Korea Moreover they didn't adopted a corrosion monitoring system. In this paper, we have been developed not only the remote automatic corrosion monitoring but also the remote corrosion control system using the high efficiency CP rectifier. This results should be used to operate the CP system effectively and economically. And also it will be possible to extend the expectation life of the Oil tanks.

• 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.5 no.1
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• pp.67-75
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• 2005

A high efficiency ZVS PWM asymmetrical half bridge converter for a plasma display panel (PDP) sustaining power modules is proposed in this paper. To achieve the ZVS of power switches for the wide load range, a small additional inductor L/sub 1kg/, which also acts as an output filter inductor, is serially inserted into the transformer's primary side. At that point, to solve the problem of ringing in the secondary rectifier caused by L/sub 1kg/, the proposed circuit employs a structure without the output filter inductor, which helps the voltages across rectifier diodes to be clamped at the output voltage. Therefore, no dissipative RC (resistor capacitor) snubber for rectifier diodes is needed and a high efficiency as well as low noise output voltage can be realized. In addition, since it has no large output inductor filter, the asymmetrical half bridge converter features a simpler structure, lower cost, less mass, and lighter weight. In addition, since all energy stored in L/sub 1kg/ is transferred to the output side, the circulating energy problem can be effectively solved. The operational principle, theoretical analysis, and design considerations are presented. To confirm the operation, validity, and features of the proposed circuit, experimental results from a 425W, 385Vdc/170Vdc prototype are presented.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.537-541
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• 2004

A high efficiency ZVS PWM asymmetrical half bridge converter for a plasma display panel (PDP) sustaining power module is proposed in this paper. To achieve the ZVS of power switches for the wide fond range, n small additional inductor $L_{lkg}$, which also acts as an output filter inductor, is serially inserted to the transformer primary side. Then, to solve the problem related to ringing in the secondary rectifier caused by $L_{lkg}$, the proposed circuit employs a structure without the output filter inductor, which helps the voltages across rectifier diodes to be clamped at the output voltage. Therefore, no dissipative RC (resistor capacitor) snubber for rectifier diodes is needed and n high efficiency as well as low noise output voltage can be realized. In addition, since it has no large output inductor filter, it features a simpler structure, lower cost, less mass, and lighter weight. Moreover, since all energy stored in $L_{lkg}$ is transferred to the output side, the circulating energy problem can be effectively solved. The operational principle, theoretical analysis, and design considerations are presented. To confirm the operation, validity, and features of the proposed circuit, experimental results from a 425W, 385Vdc/170Vdc prototype are presented.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.299-304
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• 2000

In this paper we investigate accurately the input-output characteristic of single-phase diode rectifier. The diode rectifier has some advantages of simplicity cost and high-efficiency. But it has some defects which THD of input current low PF and voltage drop of output side. In order to compensate it we analyzed using the parameter variation and introduced capacitor insertion method for reducing the distortion and increasing the PF.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.182-185
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• 2005

This paper presents a new voltage current driven method for the synchronous rectifier (SR) in a flyback topology. The proposed synchronous rectfier of voltage-current driven can operate at wide load range with high efficiency. The gate voltage of FET in the synchronous rectifier is easily controlled by resistor ratio. regardless of line and load fluctuation. The 200W (l2V/17A) prototype is built and achiveved efficiency as high as 90% at 4A, 93.2% at 7A and full load.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.12
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• pp.1602-1610
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• 2018

Induction heating can convert electrical energy to thermal energy with high conversion efficiency and quick heating. Currently, a current source rectifier/inverter-fed parallel resonant circuit is widely used as an induction heating power supply for forging applications. However, the conventional induction heating power supplies composed of phase-controlled rectifier and SCR inverter have low efficiency and low power factor at input side, and require additional starting circuitry. So this paper proposes new induction heating power supply topologies for forging applications which have high power factor, high efficiency, and large output power. It also suggests detailed design guideline.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.265-268
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• 1998

This paper presents a soft-switching average current control PWM high power factor boost converter. Conventional boost ZVT-PWM converter has a disadvantage of hard-switching for auxiliary switch at turn-off. A soft switched auxiliary switch is proposed to achieve a high performance ZVT-PWM boost rectifier. The simulation and experimental results show that soft switching operation can be maintained for wide line and load range, which in turn improves the converter performance in terms of efficiency, switching noise and circuit reliability.

• Journal of IKEEE
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• v.22 no.2
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• pp.393-401
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• 2018

In this paper, a rectifier for WPC / A4WP wireless power transmission is designed. The proposed rectifier supports both WPC (Wireless Power Consortium) and A4WP (Alliance For Wireless Power) and is designed with full-bridge rectifier. WPC transmits power at the frequency of 100kHz to 205kHz and A4WP at the frequency of 6.75MHz. Since the bridge rectifier uses a MOSFET instead of a diode, the reverse current flows and the efficiency is affected if the output voltage is higher than the input voltage. Therefore, we added the reverse current detector that detects the current flowing through the MOSFET and shut off the reverse current. The frequency discriminator is used because the rectifier has different frequency band. The proposed rectifier was designed using $0.35{\mu}m$ CMOS high voltage process. The input voltage is up to 18V and the rectifier operates at 100kH to 205kHz, 6.78MHz frequency. The maximum efficiency is 94.8% and the maximum power transfer is 5.78W.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.11
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• pp.1091-1097
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• 2013

This paper presents a rectifier with comparator using unbalanced body biasing in $0.11{\mu}m$ RF CMOS process. It is composed of MOSFETs and two comparators. The comparator is used to reduce reverse leakage current which occurs when the load voltage is higher than input voltage. For the comparator, unbalanced body biasing is devised. By using unbalanced body biasing, reference voltage for comparator changing from high state to low state is increased, and it reduces time interval for leakage current to flow. 13.56 MHz 2 Vpp signal is used for input and $1k{\Omega}$ resistor and 1 nF capacitor are used for output load for simulation and experimental environment. In simulation environment, voltage conversion efficiency(VCE) is 87.5 % and Power conversion efficiency(PCE) is 50 %. When the rectifier is measured, VCE shows 90.203 % and PCE shows 45 %.