• Proceedings of the KIPE Conference
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• 2018.11a
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• pp.203-204
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• 2018

Conventional buck-boost converter has the disadvantage that the output voltage is inverted. The single phase non-inverting buck-boost converter(SPNIBBC) used four swithes has H-bridge type Circuit. The output voltage is not inverted. The SPNIBBC can be controlled by the single carrier method and the dual carrier method according to the modulation method. In this paper, we have fabricated the converter and compared the efficiency according to the modulation method.

• Journal of Electrical Engineering and Technology
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• v.6 no.4
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• pp.527-534
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• 2011

In the present paper, the characteristics of Mega-Flux$^{(R)}$, JNEX-Core$^{(R)}$, amorphous and ferrite cores are compared to the inductor of buck-boost converters for Hybrid Electric Vehicles. Core losses are analyzed at the condition of 10 kHz sine wave excitations, and permeability fluctuations vs. temperature and magnetizing force will be analyzed and discussed. Under the specifications of the buck-boost converter for 20 kW THS-II, the power inductor will be designed with Mega-Flux$^{(R)}$ and JNEX-Core$^{(R)}$, and informative simulation results will be provided with respect to dc bias characteristics, core and copper losses.

• Journal of Electrical Engineering and Technology
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• v.6 no.4
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• pp.519-526
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• 2011

An investigation of the mechanism of period-doubling bifurcation in a voltage mode controlled buck-boost converter operating in discontinuous conduction mode is conducted from the viewpoint of nonlinear dynamical systems. The discrete iterative model describing the dynamics of the close-loop is derived. Period-doubling bifurcation occurs at certain values of the feedback factor. Results from numerical simulations and experiments are provided to verify the evolution of perioddoubling bifurcation, and the results are consistent with the theoretical analysis. These results show that the buck-boost converters exhibit a wide range of nonlinear behavior, and the system exhibits a typical period-doubling bifurcation route to chaos under particular operating conditions.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.151-153
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• 2007

In this paper, the control method of extracting maximum power from the seaflow energy is proposed. This system consists of buck-boost converter, bridge diode. The control is performed by using the variable duty ratio control of buck-boost converter. For extracting maximum power, it is necessary to know the seaflow turbine's maximum power curve and the seaflow speed measurement. But this makes the system difficult and expensive to implement. So this paper proposes the MPPT control method where the seaflow speed and the maximum power curve of the seaflow turbine are not required. The effectiveness of algorithm is simulated based on Matlab $Simulink^{(R)}$.

• Journal of Power Electronics
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• v.15 no.6
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• pp.1584-1592
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• 2015

This paper presents a nonlinear method to control a DC-DC converter and track the Maximum Power Point (MPP) of a Photovoltaic (PV) system. A backstepping controller is proposed to regulate the voltage at the input of a buck-boost converter by means of Lyapunov functions. To make the control initially faster and avoid local maximum, a regression plane is used to estimate the reference voltages that must be obtained to achieve the MPP and guarantee the maximum power extraction, modifying the conventional Perturb and Observe (P&O) method. An experimental platform has been designed to verify the validity and performance of the proposed control method. In this platform, a buck-boost converter has been built to extract the maximum power of commercial solar modules under different environmental conditions.

• Proceedings of the KIPE Conference
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• 1998.11a
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• pp.44-48
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• 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 KIPE Conference
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• 1998.07a
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• pp.260-264
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• 1998

Three phase Boost/Buck converter which have economical merits and simple control scheme, are analyzed and evaluated through comparative methods and digital simulation for equivalent load. Those play a part of voltage boost/buck as well as power factor correction with single switch. Controller operating in constant and variable frequency is used for rapid output response and stable system condition respectively. Moreover low THD property of single switched converters is available for inverter arc welding machine known as high power and low power factor. So, in this paper a comparison of the characteristics in boost and buck converter is described and then simulation results conforms the merits from point of view of power factor and voltage regulator.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.3
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• pp.141-146
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• 2001

This paper presents a one digital controller two topology PWM DC-DC converter that controls, simultaneously, the separate Buck converter and boost converter with the different specification by using an inexpensive and efficient 8 bit micro-controller. One timer interrupt is used for the detection of output feedback voltage, and other two timer interrupts are used for the generation of PWM waveform for Buck and Boost converter. The control characteristics of one digital controller two topology PWM DC-DC converter is validated by experimental results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.393-396
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• 2001

산업분야에서 많이 사용되고 있는 컴퓨터나 자동화 제조공정 둥은 전압저하나 이상전압에 민감하게 반응한다. 전력품질의 문제가 증가함에 따라 수용가 측에서는 무정전 전원장치(UPS)와 같은 일정전압을 유지할 수 있는 전압조절장치 들을 사용하고 있다. 본 논문에서는 전압조절기 응용을 위한 PWM Buck-Boost AC/AC 컨버터가 제안된다. 제안된 컨버터는 IGBT 스위칭 모듈을 사용하고 입력전압의 저하나 증가시, 그리고 부하의 변동시에 PWM 제어에 의하여 일정한 전압을 유지할 수 있다. 본 논문에서는 제안된 PWM Buck-Boost AC/AC 컨버터의 회로구성과 특징을 설명하고 이를 PSPICE 시뮬레이션을 통하여 동작특성을 보인다.

• Journal of Power Electronics
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• v.14 no.5
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• pp.899-907
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• 2014

This paper proposes a single-phase bidirectional AC/DC converter topology applied in V2G systems, which consists of an inverter and a bidirectional non-inverting buck-boost converter. This topology can operate in four modes: buck charging, boost charging, buck discharging and boost discharging with high input current quality and unity input power factor. The inverter switches at line frequency, which is different from conventional voltage source inverters. A bidirectional buck-boost converter is utilized to adapt to a wider charging voltage range. The modulation and control strategy is introduced in detail, and the switching patterns are optimized to reduce the current ripple. In addition, the semiconductor losses are analyzed. Simulation and experimental results demonstrate the validity and effectiveness of the proposed topology.