• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.7
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• pp.20-28
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• 2009

This paper presents the design of zero current switching ZCS pulse frequency modulation type DC-DC converter for magnetron power supply. A magnetron serving as the microwave source in a microwave oven is driven by a switch mode power supply (SMPS). SMPSs have the advantages of improved efficiency, reduced size and weight, regulation and the ability to operate directly from the converter DC bus. The demands of the load system and the design of the power supply required to produce constant power at 4[kV]. A magnetron power supply requires the ability to limit the load current under short circuit conditions. The current source series resonant converter is a circuit configuration which can achieve this. The main features of the proposed converter are an inherent protection against a short circuit at the output, a high voltage gain and zero current switching over a large range of output power. These characteristics make it a viable choice for the implementation of a high voltage magnetron power supply.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.3-4
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• 2011

This paper presents a survey of floating power supply based on bootstrap operation for three-level voltage-source inverters. The floating power supply for upper switches is achieved by the bootstrap capacitor charged during on-time of the switch underneath. Hence, a large number of bulky isolated DC/DC power supplies for each gate driver are reduced. The Pspice simulation results show the behavior of bootstrap devices and the performance of bootstrap capacitor voltage.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.436-441
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• 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 KIEE Conference
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• 1998.07f
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• pp.2030-2032
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• 1998

It is always necessary to high performance power supplies for the magnet system in the accelerator, especially when the number of power supplies are large. When have developed the compact power supply using switching technology instead of SCR phase control. We adopt the pulse width modulation(PWM) method with a half bridge DC/DC converter. In this way, we can make a compact system with light weight and small volume. Actual system we developed is 1.2kW, 35V/35A bipolar DC power supply current precision of +/-0.02%. It is possible to mount 10 unit in a conventional 19 rack. The built in controller has an RS422 protocol to drive 10 unit by one serial port up to 1.2km distance. If we adopt RS485 protocol, one serial port can control 32 power supplies. In this paper, we will report the design and performance of the prototype power supply.

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

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

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.7
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• pp.100-106
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• 2005

Generally, high frequency switching DC-DC converter that DC power supply for discharge lamp drive to generate ultraviolet rays(UV) is acted by hard switching mode is used. Therefore in this paper, wish to mix first existent first-side status phase shift PWM DC-DC converter and posing secondary-side status phase shift PWM DC-DC converter by high frequency link DC-DC converter that use soft switching circuit technology and develop DC power supply for discharge lamp drive. DC power supply driving Discharge lamp proposed describe validity through simulation and an experiment.

• Journal of the Korean Society of Safety
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• v.25 no.2
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• pp.24-28
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• 2010

The nuclear power Plant onsite AC electrical power sources are required to supply power to the engineering safety facility buses if the offsite power source is lost. Typically, Diesel Generators are used as the onsite power source. The 125 VAC buses are part of the onsite Class 1E AC and DC electrical power distribution system. The DC power distribution system ensure the availability of DC electrical power for system required to shutdown the reactor and maintain it in a safety condition after an anticipated operational occurrence or a postulated Design Base Accident. Recently, onsite DC power supply system trip occurs the loss of system function. To obtain the performance such as reliability and availability, we analyzed the cause of battery charger trip and described the improvement of DC power supply system reliability. Finally, we provide reliability performance criteria of charger in order to ensure the probabilistic goals for the safety of the nuclear power plants.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.4
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• pp.119-125
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• 2022

The power supply for the anti-aircraft radar homing sensor should allow the system to receive power quickly and stably without the influence of noise. For this purpose, DC-DC converters are widely used for reliable power conversion. Also, switching of DC-DC converters Frequency noise should not cause false alarms and ghosts that may affect the detection and tracking performance of the system, and it should have a check function that can monitor power in real time while the homing sensor is operating. In order to apply to anti-aircraft radar homing sensor, we developed a multi-output switching power supply with maximum output 𐩒𐩒𐩒 W, efficiency 80% or more (@100% load), output power by receiving 28VDC input, and power supply to achieve more than 80% efficiency. A DC-DC converter was applied to this large output, and the multi-output flyback method was applied to the rest of the low-power output.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.1
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• pp.16-21
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• 2012

The growth in IT industry has brought a corresponding rise in the number of connected digital devices in the distribution network. These digital loads lead to AC to DC conversion losses in order to supply power to them. The more the renewable energies and plug-in electrical vehicles penetrated our lives, the more the electrical losses are caused by AC to DC conversion process. Hence, this paper suggests the methodology for evaluating the amount of power supplied according to the ratio of DC power supply and performs an economic analysis of DC distribution system considering grid parity. In here, the cost of carbon emission reduced by renewable energy is also concerned.