• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.3
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• pp.40-49
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• 2011

This paper presents novel circuit topology of half-bridge soft-switching PWM inverter type DC-DC high power converter for DC bus feeding power plants. The proposed DC-DC power converter is composed of a typical voltage source-fed, half-bridge high frequency PWM inverter with a high frequency planar transformer link PWM control scheme and parallel capacitive lossless snubbers. The operating principle of the new DC-DC converter treated here is described by using switching mode-equivalent circuits, together with its unique features. All the active power switches in the half-bridge arms and input DC bus lines can achieve ZCS turn-on and ZVS turn-off commutation transitions. The total turn-off switching losses of the power switches can be significantly reduced. As a result, high switching frequency IGBTs can actually be selected in the frequency range of 40[kHz] under the principle of soft-switching. The performance evaluations of the experimental setup are illustrated practically.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.4
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• pp.48-53
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• 2013

In general, the LLC resonant topology consists of three stages as; square wave generator, resonant network, and rectifier network. LLC resonant converter has the time slowly varying parameters. However, the power LEDs as the load of LLC converter can be regarded as fast time varying parameters. In this paper, the mathematical model of half-bridge resonant converter including with the power LEDs is introduced for the current controller design model. Using this controller design model, the parameter adaptive output feedback controller will be designed to control the power LEDs current. In order to show the validities of the proposed model, the parameter adaptive output feedback controller, the experimental investigation will be presented.

• Journal of Power Electronics
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• v.10 no.1
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• pp.14-20
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• 2010

In this paper, a tightly regulated triple output asymmetrical half bridge flyback (ASHF) converter is proposed. In order to regulate all output voltages, pulse frequency modulation (PFM), pulse width modulation (PWM) and phase delay (PD) are used simultaneously. In comparison with the conventional PWM-PD method, the interactions among the control variables are minimized and the operating range is increased. By the utilization of a multi winding transformer, the auxiliary transformer and the blocking capacitor are eliminated and the size and cost of the proposed converter is reduced. The operation principle of the converter is explained and the modes of operation are investigated. Based on the results, the steady state characteristics of the converter are explored. A 24V/10A, 12V/5A, 5V/10A hardware prototype is built and tested to verify the analysis results and the voltage regulation of the triple outputs of the proposed converter.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.8
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• pp.1538-1543
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• 2009

The electric ballast for ceramic metal halide lamp needs a protection circuit to prevent from over voltage and over current in the case that the lamp or the electric ballast are in faults. In this paper, cost-effective and high performance protection circuit is proposed for the electric ballast. The proposed protection circuit is adapted to the electric ballast with $LC_SC_P$ resonance type half bridge inverter. The experimental results demonstrate that the proposed circuit can protect effectively under open and short fault conditions.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.538-540
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• 1997

A new dual half bridge induction heating cooker circuit with multiple loads is proposed for reducing the acoustics noise which is caused by the difference between operating frequencies q adjacent loads. This circuit has minimum loss due to the zero voltage switching characteristic. According to the mode analysis of the proposed circuit, we explain the operation of the dual half bridge induction heating cooker circuit The proto-type circuit with 2.8kW power consumption is builted and tested to verify the operation q the proposed circuit.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.251-253
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• 2006

This paper presents a start-up in-rush current reduction technique of asymmetry half-bridge DC/DC converter for PC power supply. The proposed converter is composed center-tapped half-bridge converter with blocking capacitor. The proposed converter can reduce the severe in-rush current when the proposed converter is power up. The validity of this study is confirmed from the experimental results.

• Journal of Power Electronics
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• v.7 no.1
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• pp.21-27
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• 2007

This paper investigates a PID fuzzy controller for output voltage regulation of a current-doubler-rectified asymmetric half-bridge (CDRAHB) DC/DC converter. The controller is a PD-type fuzzy controller in parallel with a linear integral controller. The PD type fuzzy controller is for providing the varying gain at the different operating conditions to regulate the output voltage. The linear integral controller is for removing the steady-state error of the output voltage. In order to show the outstanding dynamic characteristics of the proposed controller, PSIM simulation studies are carried out and compared to the results for which the conventional loop gain design method is used.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.361-363
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• 1999

This paper proposes an SSSC based on 3-level half-bridge inverters. The dynamic characteristic of the proposed SSSC was analyzed by EMTP simulation, assuming that the SSSC is inserted in the transmission line of the one-machine-infinite-bus power system. The proposed SSSC has six 3-level half-bridge inverters per phase, which operates in PWM mode. The proposed SSSC generates a quasi-sinusoidal output voltage by 90 degree phase shift to the line current. The proposed SSSC does not require the coupling transformer for voltage injection, and has a flexibility in operation voltage by increasing the number of series connection.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.7 no.1
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• pp.77-84
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• 2007

In this paper, Takagi-Sugeno (TS) fuzzy integral control is investigated to regulate the output voltage of an asymmetric half-bridge (AHB) DC/DC converter; First, we model the dynamic characteristics of the AHB DC/DC converter with state-space averaging method and small perturbation at an operating point. After introducing an additional integral state of the output regulation error, we obtain the $5^{th}$-order TS fuzzy model of the AHB DC/DC converter. Second, the concept of the parallel distributed compensation is applied to design the fuzzy integral controller, in which the state feedback gains are obtained by solving the linear matrix inequalities (LMIs). Finally, simulation results are presented to show the performance of the considered design method as the output voltage regulator and compared to the results for which the conventional loop gain method is used.

• Fire Science and Engineering
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• v.14 no.1
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• pp.22-26
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• 2000

Emergency lamp is installation usage on an emergency situation or firing. It's an offer at least of brightness. It's lighting to common source usually. It's transferred to reserve battery on power stoppage. This emergency lamp is lighted from solar cell system. The solar cell should be operated at the maximum power point. This paper proposes the new control method that half-bridge inverter using the solar cell can operate emergency lamp.