• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.6
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• pp.593-600
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• 2013

The asymmetric pulsed DC reactive magnetron sputtering system is widely used for the high quality plasma sputtering process such as a thin film deposition. In asymmetric pulsed DC power supply a reverse voltage is applied to the target periodically to minimize arc discharging effect. When sputtering in the mid-frequency range (20-350 kHz), the periodic target voltage reversals suppress arc formation at the target and provide long-term process stability. Thus, high quality, defect-free coatings of these materials can now be deposited at competitive rates. In this paper, a new style asymmetric pulsed DC power supply including mid-transformer is presented. In the proposed, an energy recovery circuit is adopted to reduce the mutual inductance of the transformer. As a result, the system dynamics of the voltage control loop is increased highly and the non-linear voltage boosting effect of the conventional system is removed. This work was proved through simulation and laboratory based experimental study.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.197-202
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• 2019

A small millimeter-wave tracking radar power supply must provide stable power with minimal ripple noise and the switching frequency noise of the DC-DC converter must have a real-time self-test capability through on-the-fly monitoring without causing false alarms and ghost In this study, we developed a multi-output switching power supply with output power of more than 80% (@ 100% load) and 10 output power by adopting + 28VDC input for application to small millimeter wave tracking radar, DC-DC converter is applied for large power output and multi-output flyback method is applied for the remaining small power output. The test results show that 85% efficiency efficiency is achieved under 100% load condition.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.343-349
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• 2001

In this study we examined the method to estimate numerically the amount of the regenerated power and the excess regenerated power produced in the DC electric power supply system for the urban light rail transit system. And their economic feasibilities are also studied. For this study DC electric power supply system is simulated and the numerical analysis of the regenerated power and the excess regenerated power are conducted. The study result on the sample system shows that the facility to consume the excess regenerated power or the inverting equipment to reuse the excess regenerated power in the electric substation is feasible economically.

• Journal of Electrical Engineering and Technology
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• v.6 no.1
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• pp.67-75
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• 2011

The development of electric vehicle power electronics system control, composed of DC-AC inverters and DC-DC converters, attract much research interest in the modern industry. A DC-AC inverter supplies the high-power motor torques of the propulsion system and utility loads of electric vehicles, whereas a DC-DC converter supplies the conventional low-power and low-voltage loads. However, the need for high-power bidirectional DC-DC converters in future electric vehicles has led to the development of many new topologies of DC-DC converters. The nonlinear control of power converters is an active research area in the field of power electronics. This paper focuses on the use of the fuzzy sliding mode strategy as a control strategy for buck-boost DC-DC converter power supplies in electric vehicles. The proposed fuzzy controller specifies changes in control signals based on the surface and knowledge on surface changes to satisfy the sliding mode stability and attraction conditions. The performance of the proposed fuzzy sliding controller is compared to that of the classical sliding mode controller. The satisfactory simulation results show the efficiency of the proposed control law, which reduces the chattering phenomenon. Moreover, the obtained results prove the robustness of the proposed control law against variations in load resistance and input voltage in the studied converter.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.608-611
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• 2001

This paper is indicating the problems, which are the conduction loss on the high frequency transformer, the protection of rectification diode as the snubber loss and the stress of switching main devices, as be made high current and high speed in the phase-shift switching full-bridge DC-DC converter is used the power supply's main circuit of high capacity. In this paper, to improve those problems, it is proposed that is the resonant circuit auxiliary can be reduced conduction losses and stabilized output control. And, it is constructed prototype of the power supply as the result of computer simulations.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.5
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• pp.397-401
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• 2022

The construction of the ITER tokamak machine is ongoing at a 77% process rate to achieve the first plasma in 2025. The 18 sets of power supply systems comprising 400 MVA thyristor AC/DC converters for the superconducting magnets supplied by Korea (KO) are being installed with other systems, such as PF converters (China), DC busbars (Russia), and cooling water systems (India), in two buildings (Europe). The system interfaces have been defined during the design stage, and the systems have been manufactured. However, during the on-site installation work, several installation and integration issues emerged due to the manufacturing tolerance and design mistakes. To continue the installation and testing, the engineers of each system resolved the interface issues, planned the commissioning, and integrated the test plan. This paper describes the on-site installation status and issues and the commissioning plan of KO AC/DC converters.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.5
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• pp.31-40
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• 2008

Recently, Contactless Power Supply(CPS) system has been broadly studied as a power supply system for Flat Panel Display(FPD) material transfer equipments. In mass production line, CPS systems on material transfer equipment are applied only in the straight sections with single operating vehicle. The formal CPS system was not adequate for curved section nor multiple operating vehicles. Therefore, this paper presents CPS system that consists of straight and curved section with multiple operation vehicles. The circuit topology of CPS system consists of full bridge configured serial-parallel resonant DC/DC converter. The control method for CPS system consists of duty control method on the primary power supply system to maintain constant resonant current. And the secondary power supply systems of multiple vehicles are self controled to maintain constant output voltage. Practically, the test result of dual vehicles on straight and curved section of material transfer equipments were satisfactory, and proved it's applicability on commercial use.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1825-1831
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• 2011

One of the major trends in traction power electronics is increasing the switching frequencies. The advances in the frequency elevation have made it possible to reduce the total size and weight of the passive components such as capacitors, inductors and transformers in the DC/DC converter and hence to increase the power density. The traction dynamic performance is also improved. This document describes several aspects relating to the design of resonant DC/DC converter operating at high frequency(10KHz) and the converter topologies and the control method of MAGLEV, which result in soft switching, are discussed.

• Journal of Power Electronics
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• v.15 no.2
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• pp.399-410
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• 2015

A 6.5 V/50 kA high-frequency switching power supply (HSPS) system composed of 10 power modules is developed to meet the requirements of copper-foil electrolysis. The power module is composed of a two-leg pulse width modulation (PWM) rectifier and a DC/DC converter. The DC/DC converter adopts two full-wave rectifiers in parallel to enhance the output. For the two-leg PWM rectifier, the ripple of the DC-link voltage is derived. A composite control method with a ripple filter is then proposed to effectively improve the performance of the rectifier. To meet the process demand of copper-foil electrolysis, the virtual impedance-based current-sharing control method with load current full feedforward is proposed for n-parallel DC/DC converters. The roles of load current feedforward and virtual impedance are analyzed, and the current-sharing control model of the HSPS system is derived. Virtual impedance is used to adjust the current-sharing impedance without changing the equivalent output impedance, which can effectively reduce current-sharing errors. Finally, simulation and experimental results verify the structure and control method.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.5
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• pp.99-103
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• 2022

Millimeter-wave tracking radars operate in various environmental restrictions, thus they demand stable power sources with low noise level under high fluctuation of input voltage. This paper presents the design and implementation of the compact power supply with max power of 727 W for Ka-band tracking radar applications. To meet requirements of voltage accuracy and system efficiency for transceiver circuits, upper plates of buck converters are attached on the covers of power supply for efficient heat dissipation. The proposed power supply achieves system efficiency of 88.4 %, output voltage accuracy of ±2 % and noise level of <1% under full load conditions.