• Journal of Power Electronics
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• v.14 no.6
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• pp.1263-1271
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• 2014

A novel hysteresis PWM control strategy for synchronous buck converter is proposed. The proposed control strategy is based on ampere-second balance of the modulate capacitor, which not only offers faster transient response to meet the challenges of the power supply requirements of fast dynamic load changes, but also provides better stability and solves the compensation problem of error amplifier in the conversional voltage PWM control. Finally, the steady-state and dynamic operation of the control method is analyzed and verified by simulation and experimental results.

• Journal of Power Electronics
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• v.14 no.6
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• pp.1217-1223
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• 2014

A novel half load-cycle worked dual input single output (DISO) DC/AC inverter is presented. The basic circuit consists of a dual buck regulator, which works in continuous current mode. The working principle of DISO DC/AC inverter has been used. The control method applied for half load-cycle worked DISO DC/AC inverter has been studied. The control effects of the open-loop proportional control and closed-loop proportional-integral control are compared by using PSIM software. The parameters are adopted in the realistic simulation and experiment test. Moreover, the waveforms, such as voltage of modulation reference signal and output voltage, were given. The simulation and experiment results proved that the half load-cycle worked DISO DC/AC inverter could achieve good performance, gain a line frequency of 50 Hz, and verify the correctness of theoretical analysis.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.951-954
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• 1998

This paper proposed that a high power AC-DC buck converter topology of high efficiency using loss-less snubber operates with four chopper connecting a number of parallel circuit. To improve these, a large number of soft switching topologies included a resonant circuit have been proposed. And, some simulative resutls on computer is included to confirm the validity of the analytical results. The partial resonant circuit makes use of a inductor using step-down and a condenser of loss-less snubber. The result is that the switching loss is very low and the efficiency of system is high. And the snubber condenser used in partial resonant circuit makes charging energy regenerated at input power source of rresonant operation. The proposed conversion system is deemed the most suitable for high power applications where the power switching devices are used.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.2
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• pp.98-104
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• 2012

This paper presents a novel transformer isolated parallel connected full-bridge dc-dc converter using recently developed trans-Z-source network. Unlike the traditional voltage -fed or current-fed converters, the proposed converter can be open- and short-circuited without damaging switching devices. Therefore, the desired buck and boost function can be achieved and the converter reliability can be greatly improved. A 6 kW prototype dc-dc converter is built and tested to verify performances of the proposed converter.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.7
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• pp.281-285
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• 2013

Transfer function of Buk DC-DC converter is derived using Laplace transformed LC filter. Using root locus and simulation waveform, this paper shows that Type2 controller proposed in reference has poor performance. Using root locus PI controller has designed. Using operational amp, PI controller is realized. Properly operated Type2 controller is proposed and proved using simulation result.

• Journal of Industrial Technology
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• v.31 no.B
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• pp.67-73
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• 2011

Ceramic metal halide lamps have been widely used due to long lifetime, high luminous efficiency and good colour rendering. In this paper, we developed dimming control system of electronic ballast for 70W ceramic metal halide lamp by using 1-10V interface. The proposed electronic ballast is consists of EMI filter, Full-wave rectifier, Active PFC, DBI(Dual Buck Inverter), Igniter and control circuit.It enables to supply both low-frequency rectangular wave voltage and current to the lamp by using DBI(Dual Bcuk Inverter) structure. By using 1-10V interface, the system that able to dimming the lamp is demonstrated by P-spice simulation and experimental results.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.278-281
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• 1999

In a utility interactive photovoltaic system, a PWM inverter is used for the connection between the photovoltaic arrays and the utility. The DC current becomes pulsated causes the distortion of the AC current waveform. This paper presents the reduced pulsation of DC input current by operating the inverter with buck-boost chopper in the discontinuous conduction mode. The DC current with contains harmonics component is analyzed by means of separating into two terms of a ripple component and a direct component. The constant DC current without pulsation is supplied from photovoltaic array to the inverter. The proposed inverter system provide a sinusoidal AC current for domestic loads and the utility line with unity power factor.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.4
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• pp.224-230
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• 2006

The conventional way to implement a bidirectional converter with boost/buck has been to use two general purpose PWM ICs with a single supply voltage. In this case, when one direction mode is in operation, the other is disabled and the output of the error amplifier of the disabled IC may be saturated to a maximum value or zero. Therefore, during mode transition, a circuit which can disable the switching operation for a certain time interval is required making it impossible to get a seamless transition. In this paper, the limitations of the conventional 42V/14V bi-directional DC/DC converter implemented with general current mode PWM ICs with a single supply voltage are reviewed and a new current mode PWM controller circuit with a dual voltage system is proposed. The validity of the proposed circuit is investigated through simulation. and experiments.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.9
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• pp.590-597
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• 2000

Design of single state AC-DC converter with high power factor for low level applications is proposed. The proposed converter is obtained from the integration of a buck-boost converter and the half-bridge DC-DC converter. This converter gives the good power factor correction low line current harmonic distortions and tight output voltage regulations. This converter also has a high efficiency by employing an soft switching method and synchronous rectifier. The modelling and detailed analysis for the proposed converter are performed. To verify the performance of the proposed converter a 100W converter has been designed

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.338-340
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• 2001

Power factor improved for single-phase buck-converter is studied in the paper. To sinusoidal waveform the input current with a near-unity power factor over a wide variety of operating conditions, the output capacitor is operated with voltage reversibility for the supply by arranging the auxiliary diode and power switching device. Then the output voltage is superposed on the input voltage during on time duration of power switching devices in order to minimize the input current distortion caused by the small input voltage when changing the polarity. The tested setup, using two insulated gate bipolar transistors(IGBT) and a microcomputer, is implemented and IGBT are switched with 20[kHz], which is out of the audible band. Moreover, a rigorous state-space analysis is introduced to predict the operation of the rectifier. The simulated results confirm that the input current can be sinusoidal waveform with a near-unity power factor and a satisfactory output voltage regulation can be achieved.