• Proceedings of the KIPE Conference
• /
• 2005.07a
• /
• pp.669-672
• /
• 2005

Normally, the buck converter is used for the charging converter of photovoltaic generator because this converter has good characteristics compare with boost and buck-booster converter But, in case of the sollar-cell voltage is lower than charging voltage, we cannot charge the sollar energy to the charger. So, in this paper, we proposed the novel hybrid converter using by combination of buck and boost converter for the charging converter of photovoltaic generator, as a results, it can operate buck, boost and buck-boost mode. The proposed novel converter has the same characteristics of the existent buck converter and furthermore it can operate as a boost converter. So, we can make the more effective photovoltaic charging system.

• Journal of Power Electronics
• /
• v.15 no.1
• /
• pp.31-38
• /
• 2015

In this paper, a buck-boost type battery charger is developed for charging battery set with a lower voltage. This battery charger is configured by a rectifier circuit, an integrated boost/buck power converter and a switched capacitors circuit. A boost power converter and a buck power converter sharing a common power electronic switch are integrated to form the integrated boost/buck power converter. By controlling the common power electronic switch, the battery charger performs a hybrid constant-current/constant-voltage charging method and gets a high input power factor. Accordingly, both the power circuit and the control circuit of the developed battery charger are simplified. The switched capacitors circuit is applied to be the output of the boost converter and the input of the buck converter. The switched capacitors circuit can change its voltage according to the utility voltage so as to reduce the step-up voltage gain of the boost converter when the utility voltage is small. Hence, the power efficiency of a buck-boost type battery charger can be improved. Moreover, the step-down voltage gain of the buck power converter is reduced to increase the controllable range of the duty ratio for the common power electronic switch. A prototype is developed and tested to verify the performance of the proposed battery charger.

• Journal of Power Electronics
• /
• v.7 no.4
• /
• pp.318-327
• /
• 2007

The design and performance analysis of a power factor corrected (PFC), single-phase, single switch flyback buck-boost ac-dc converter is carried out for low power battery charging applications. The proposed configuration of the flyback buck-boost ac-dc converter consists of only one switch and operates in discontinuous current mode (DCM), resulting in simplicity in design and manufacturing and reduction in input current total harmonic distortion (THD). The design procedure of the flyback buck-boost ac-dc converter is presented for the battery charging application. To verify and investigate the design and performance, a simulation study of the flyback buck-boost converter in DCM is performed using the PSIM6.0 platform. A laboratory prototype of the proposed single switch flyback buck-boost ac-dc converter is developed and test results are presented to validate the design and developed model of the system.

• Journal of Power Electronics
• /
• v.9 no.3
• /
• pp.430-437
• /
• 2009

This paper presents the dynamic characteristics of buck and buck-boost dc-dc converters with digital filters. At first, the PID, the minimum phase FIR filter and the IIR filter controls are discussed in the buck dc-dc converter. Comparisons of the dynamic characteristics between the buck and buck-boost converters are then discussed. As a result, it is clarified that the superior dynamic characteristics are realized in the IIR filter method. In the buck converter, the undershoot is less than 2% and the transient time is less than 0.4ms. On the other hand, in the buck-boost converter, the undershoot is about 3%. However, the transient time is approximately over 4ms because the output capacitance is too large to suppress the output voltage ripple in this type of converter.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.48 no.11
• /
• pp.663-669
• /
• 1999

This paper presents new self excited DC-DC converters such as Buck-boost type, Buck type and also non-inverting Buck-boost type. The proposed converters has the following advantages: simple topology, small number of circuit components, easy control method. Therefore, these converters are suitable for the portable appliances with battery source. It is especially suited for low power DC-DC conversion applications where non isolation output power is usually required. The steady state characteristics of proposed self exciting Buck-boost DC-DC converter are analysis and the result shows good agreement with experimental value. Furthermore the experimental results for 50W class self oscillating Buck-boost DC-DC converter have been obtained, which demonstrate the high efficiency and good performance.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.3
• /
• pp.560-565
• /
• 2011

This paper proposes the design of micro energy harvesting system by using thermoplastic polyurethane(TPU), which harvests electric energy from the kinetic energy of pedestrian and drives the desired load, and applied it to the self-generating shoes. Also, we designed the buck-boost converter in discontinuous conduction mode(DCM) which functions as a resistor emulator(RE) such that converter's average input current is proportional to input voltage, and it results in transfer of maximum power to buck-boost converter according to control behavior that converter's input resistance is matched with TPU's internal resistance. Therefore, this paper confirms the validity of proposed control scheme and possibility of application for self-generating shoes, from the obtained characteristic of designed micro energy harvesting system by using a TPU and buck-boost converter in DCM.

• Proceedings of the KIEE Conference
• /
• 2003.04a
• /
• pp.166-169
• /
• 2003

In this paper, a PWM Buck-Boost AC-AC converter for improvement of power quality of custom power is presented. The PWM Buck-Boost AC-AC converter is modelled by using circuit DQ transformation whereby the design guideline is obtained. Based on the analysis, the converter system is implemented with the design criteria and the experimental results show the validity of modelling and analysis.

• Proceedings of the KIEE Conference
• /
• 1994.07a
• /
• pp.348-350
• /
• 1994

In this paper, bi-directional buck-boost DC-DC converter for bus regulation system is presented. This converter which has one buck and one boost topology achieves bi-directional power flow using a common power inductor and alternative power switches. By connecting the battery to bus line, it can be regulated to bus voltage and charged the battery alternatively. And as an application, a mode controller is adopted to the converter.

• Proceedings of the KIPE Conference
• /
• 2002.11a
• /
• pp.129-132
• /
• 2002

In this paper, a PWM Buck-Boost AC-AC converter for improvement of power quality of custom power is presented. The PWM Buck-Boost AC-AC converter is modelled by using circuit DQ transformation whereby the both static and dynamic characteristics are analyzed completely. Finally, the converter system is implemented with the design criteria and the experimental results show the validity of modelling and analysis.

• Journal of the Korean Society of Industry Convergence
• /
• v.20 no.2
• /
• pp.97-104
• /
• 2017

In the present industrial field, the demand for the development of the solar power source device and the charging device for the solar cell is gradually increasing. The solar charger is largely divided into a DC-DC converter that converts the voltage generated from the sunlight to a charging voltage, and a battery and a charger that are charged with an actual battery. The conventional charger topology is used either as a Buck converter or a Boost converter alone, which has the disadvantage that the battery can not always be charged to the desired maximum power as input and output conditions change. Although studies using a topology capable of boosting and stepping have been carried out, Buck-Boost converters or Sepic converters with relatively low efficiency have been used. In this paper, we propose a new Buck Boost combination power converter topology structure that can use Buck converter and Boost converter at the same time to improve inductor current ripple and power converter efficiency caused by wide voltage control range like solar charger.