• Proceedings of the KIPE Conference
• /
• 2012.11a
• /
• pp.193-194
• /
• 2012

The bidirectional boost-buck chopper type AC voltage regulator is presented in this paper. The main characteristic of the AC chopper is the fact that it generates an output AC voltage larger or lower than the input AC one, depending of the instantaneous duty-cycle. Boost-buck chopper type AC voltage regulator, derived from the DC chopper modulated method, is a kind of direct AC-AC voltage converter and has many advantages: such as fast response speed, low harmonics and high power factor. It adopts high switching frequency AC chopper technique and can do wide range step less AC voltage regulation.

• Proceedings of the KIEE Conference
• /
• 1998.07f
• /
• pp.2115-2117
• /
• 1998

The output characteristics of solar cell are nonlinear, and these characteristics vary with load solar insolation. solar cell temperature. The PWM power inverter is realized by driving a inverter constructed with a high frequency buck-boost chopper in the discontinuous conduction mode(DCM). This paper present a buck-boost PWM inverter and its application for residential system.

• Proceedings of the KIEE Conference
• /
• 1996.07a
• /
• pp.426-430
• /
• 1996

A new generator excitation system using a boost-buck chopper as a kind of static exciters is proposed to overcome the lack of field forcing capability of the bus fed exciter under the Input line fault condition. It increases or maintains the generator field current by boosting the field voltage in the case of the input AC line voltage drop during and immediately after a fault. The validity of the proposed excitation system is verified with the computer simulation. The generator stability according to the each difference exciter is tested using a commercial software package-CYME. The simulation results of the stability analysis on the generator with the proposed exciter is better than that of the bus fed exciter. This boost-buck chopper exciter can be simply implemented and controlled by the modem power electronics technology.

• Proceedings of the KIPE Conference
• /
• 1998.11a
• /
• pp.44-48
• /
• 1998

In the buck-boost DC-DC converter which is used at a certain situation such as in factories where loads often change a lot, the switches in the device make big energy loss in operating at Buck-Boost Mode due to hard switching and are affected by lots of stresses which decrease the efficiency rate of the converter. In order to improve this problem, to decrease the loss of snubber and switching, it has been investigated that zero voltage switching mode and zero current switching mode which make the operation of switches with soft switching. For the more sophisticated and advanced device, this paper is presented the Partial Resonant Soft Switching Mode Power Converter which is adapted the power converter having the partial resonant soft switching mode, that makes switches operate when the resonant current or voltage becomes zero by making the resonant circuit partially at turning on and off of the switches with suitable layout of the resonant elements and switch elements in the converter. Also, this paper includes the analysis and simulation of the Partial Resonant type Buck-Boost Chopper.

• Proceedings of the KIEE Conference
• /
• 1998.07f
• /
• pp.2036-2038
• /
• 1998

In the buck-boost DC-DC chopper which is used at a certain situation such as in factories where loads often change a lot, the switches in the device make big energy loss in operating at Buck-Boost Mode due to hard switching and are affected by lots of stresses which decrease the efficiency rate of the converter. In order to improve this problem, to decrease the loss of snubber and switching, it has been investigated that zero voltage switching mode and zero current switching mode which make the operation of switches with soft switching. For the more sophisticated and advanced device, this paper is presented the Partial Resonant Soft Switching Mode Power Converter which is adapted the power converter having the partial resonant soft switching mode, that makes switches operate when the resonant current or voltage becomes zero by making the resonant circuit partially at turning on and off of the switches with suitable layout of the resonant elements and switch elements in the converter. Also, this paper includes the analysis and simulation of the Partial Resonant type Buck-Boost Chopper.

• Proceedings of the KIPE Conference
• /
• 1998.07a
• /
• pp.39-42
• /
• 1998

This paper is presented the Partial Resonant Soft Switching Mode Power Converter which is adapted the power converter having the partial resonant soft switching mode, that makes switches operated when the resonant current or voltage becomes zero by making the resonant circuit partially at turning on and off of the switches with suitable layout of the resonant elements and switch elements in the converter. Also, this paper includes the analysis and simulation of the Partial Resonant type Buck-Boost Chopper.

• Proceedings of the KIPE Conference
• /
• 2007.07a
• /
• pp.80-82
• /
• 2007

In this paper, we proposed new maximum electric power tracking algorithm by composing Buck-boost chopper circuit to charge electric power from wind energy generator which is under low and high wind velocity. The break function is also proposed with the existed buck-boost chopper switch. We made a proto-type as a lab level to verify appropriateness of using proposed circuit.

• Proceedings of the KIPE Conference
• /
• 1998.07a
• /
• pp.113-115
• /
• 1998

This paper present a buck-boost PWM inverter and its application for residential system. The PWM power inverter is realized by driving a inverter constructed with a high frequency buck-boost chopper in the discontinuous conduction mode (DCM)

• The Transactions of the Korean Institute of Power Electronics
• /
• v.4 no.4
• /
• pp.325-331
• /
• 1999

In a utility interactive photovoltaic generation system. a PWM inverter is used for the connection between the p photovoltaic arrays and the utility. The dc current becomes pulsated when the conventional inverter system operates i in the continuous current mode and de current pulsation causes the distortion of the accurrent waveform. This paper p presents the reduced pulsation of de input current by operating the inverter with buck-boost chopper in the d discontinuous conduction mode. The dc current which contains harmonic component is analyzed by means of s separating into two terms of a ripple component and a direct component. The constant dc current without p pulsation is supplied from photovoltaic array to the inverter. The proposed inverter system provides a sinusoidal ac c current for domestic loads and the utility line with unity power factor.

• Proceedings of the KIPE Conference
• /
• 2013.07a
• /
• pp.337-338
• /
• 2013

Combination the several type of single phase power conversion utilized simply topology are proposed in this paper. Totally four kind of converter are investigated, they are Boost AC/AC Converter, Buck AC/AC Converter, Boost AC/DC Converter, and Buck DC/AC Converter. Two types action mode are presented to determine the functional of circuit. First is AC chopper action mode, representation of the AC/AC converter. AC chopper action mode offered the sinusoidal current waveform, better power factor, faster dynamics, and smaller input/output filter. They present high robustness, offer safe commutation and have high efficiency. The second is full bridge action mode, determined the transformation AC to DC power and otherwise. Four switching devices and one magnetic contactor will establish the mode operation of circuit and manage the flow of power proceed in proper. The correction and advance of the kind of converter are verified by simulation.