• Proceedings of the IEEK Conference
• /
• 2008.06a
• /
• pp.499-500
• /
• 2008

In this paper, we design and implement the monolithic power factor correction IC for system power modules using a high voltage(50V) CMOS process. The power factor correction IC is designed for power applications, such as refrigerator, air-conditioner, etc. It includes low voltage logic, 5V regulator, analog control circuit, high-voltage high current output drivers, and several protection circuits. And also, the designed IC has standby detection function which detects the output power of the converter stage and generates system down signal when load device is under the standby condition. The simulation and experimental results show that the designed IC acts properly as power factor correction IC with efficient protective functions.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.7 no.5
• /
• pp.453-464
• /
• 2002

The electrorheological(ER) fluid is a new material and is used for the mechanical motion devices such as semi-active suspensions, high speed clutches, and vibration isolators. The ER fluid applications need high voltage power supplies having special requirements to control the viscosity of the ER fluid. This paper deals with the development of the high voltage power supply for the semi-active suspension system using the ER fluid. The characteristics of the ER fluid are analyzed, and the design and implementation of the high voltage power supply are presented. It is well demonstrated through the experiment that the developed high voltage power supply shows a good performance suitable for the ER fluid application.

• Proceedings of the KSR Conference
• /
• 2002.10b
• /
• pp.989-994
• /
• 2002

In case the fault occurs in railway high voltage power supply network, protective relaying system must selectively detect 1 wire ground fault of grounding or non-grounding system. And this study presents railway high voltage power supply system model using PSCAD/EMTDC Vet 3.08 for circuit analysis and fault studies. In this paper, we propose protection method of non-grounding system of railway high voltage power supply system. The result shows its usefulness.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.19 no.3
• /
• pp.211-219
• /
• 2014

This paper proposes a low voltage high current LLC resonant converter for Green PC. Green PC is composed of a lot of blade PCs, and it is a centralized system to manage them in computer center. Green PC should require that its power supplies have several characteristics such as low output voltage, high output current, and high power conversion efficiency. Conventional PSFB (Phase Shift Full Bridge) converter is usually used as DC/DC converter for computer power supply because it has high power conversion efficiency thanks to ZVS (Zero Voltage Switching) operation under middle and high load conditions. However, this converter has some problems such as large switching noise and limitation of ZVS operation under light load condition. In order to improve the performance of power supply for Green PC, a new power supply using popular high efficiency LLC resonant converter for low voltage and high current application is proposed in this paper. The proposed power supply has ZVS capability over the entire load range, thus resulting in good efficiency and high switching frequency. Experimental results verify the performance of the proposed power supply for Green PC using 2[kW] (19[V], 105[A]) rated prototype converter.

• Proceedings of the KIPE Conference
• /
• 1998.10a
• /
• pp.436-441
• /
• 1998

This paper proposes an novel dc power supply using modified multilevel ac/dc converter. The output voltage of the power supply can be disconnected from and reapplied to the load rapidly. Therefore the power supply is suitable for a load having frequent short circuit such as ion source. The proposed scheme improves the performance, efficiency, and reliability and reduces the cost of the conventional power supply system for an ion beam acceleration.

• Proceedings of the KIPE Conference
• /
• 2010.07a
• /
• pp.281-282
• /
• 2010

The microwave power supply is mainly composed of the cathode power supply supplying the beam voltage and beam current of the gyrotron and body power supply for the single depressed collector (SDC) operation, which requires the cathode voltage/current of 80 kV/24 A for the cathode and +24 kV for the body. This paper is describing the power supply system for the gyrotron of KSTAR.

• ETRI Journal
• /
• v.34 no.5
• /
• pp.727-733
• /
• 2012

This paper demonstrates a new driving scheme that allows reducing the supply voltage of data drivers for low-power active matrix organic light-emitting diode (AMOLED) displays. The proposed technique drives down the data voltage range by 50%, which subsequently diminishes in the peak power consumption of data drivers at the full white pattern by 75%. Because the gate voltage of a driving thin film transistor covers the same range as a conventional driving scheme by means of a level-shifting scheme, the low-data supply scheme achieves the equivalent dynamic range of OLED currents. The average power consumption of data drivers is reduced by 60% over 24 test images, and power consumption is kept below 25%.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.53 no.1
• /
• pp.47-54
• /
• 2004

A new high voltage DC power supply is proposed. The proposed power supply is constructed with several power converters connected in series. It is easy to obtain high DC voltage for the same structure of each power converter. The output DC power of the proposed power supply can be disconnected from the load within several hundred microseconds at the instant of a load short-circuit fault. The rising time of the output DC voltage is also as small as several hundred microseconds, and there is no overshoot of the voltage because all of the output filter capacitors keep undischarged state even in load short-circuit condition. Therefore, the proposed scheme is suitable for the protection of frequent output short-circuit and fast on/off switching of output DC voltage. The proposed power supply has improved features such as simple structure, high power factor, and reduced size and volume compared with the conventional schemes. The operating principle is described and the validity of the proposed scheme is proved through simulations and experiments.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.52 no.7
• /
• pp.335-342
• /
• 2003

This paper presents a forward type high voltage pulse power supply for high voltage small current, which can be designed as a simple circuit configuration and managed easily using Power-MOSFET in the view of commercialization. According to the switching frequency, coupling factor(k) and duty ratio(D), the Principle of basic operation and the characteristics of the proposed pulse power supply are estimated. Simulation results have demonstrated the feasibility of the proposed pulse power supply. Also experimental results are presented to verify theoretical discussion with a lamp type ozonizer as a load. For studying the application at the part of environment of water, When ozonizer gas reacts with a colon bacillus, the sterilization characteristics of a colon bacillus according to the ozone concentration and response time have been investigated. This proposed pulse power supply will be able to be practically used as a pulse power supply in various environment improvement facilities like sterilization of colon bacillus, deodorization, and Nox gas elimination.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.13 no.3
• /
• pp.196-205
• /
• 2008

A noble polarity inversion dc/dc power conversion circuit that has the high input-output voltage conversion ration characteristics is presented for high voltage DC power supply applications. The proposed circuit features the reduced voltage stresses of the component compared to those of the conventional ones. The operational principles of the proposed circuit is analyzed and comparative features are presented. The simulation results and experimental results are presented to verify the validity of the proposed circuit.