• Journal of Biomedical Engineering Research
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• v.24 no.5
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• pp.391-399
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• 2003

Intravascular oxygenation represents an attractive. alternative support modality for therapy originated with acute respiratory distress syndrome(ARDS). However. the clinical study concluded that more gas exchange was needed for intravascular oxygenation to be clinically effective in ARDS treatment. In this study, we tried to enhance gas exchange on the VIVLAD using microencapsulation of hemoglobin and perfluorocarbon emulsion(PFC emulsion). Blood gas measurements were performed by collecting blood samples from the arterial and venous sides of the circuit, and processing them in a blood/gas analyzer. The function of hemosome. blood/hemosome mixed solution. and blood/PFC emulsion mixed solution were tested by an oxygen dissociation curve using a blood/gas analyzer. As a result, it was shown that the oxygen transfer of hemosome and blood/hemosome mixed solution were higher than that of whole blood. Also. it showed that the carbon dioxide transfer of whole blood/PFC emulsion mixed solution was higher than that of others. Therefore, we determined that hemosome and PFC emulsion could increase oxygen transfer and carbon dioxide transfer. respectively.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.6
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• pp.465-471
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• 2007

The system efficiency of the proposed Buck-Boost AC-DC converter is increased by soft switching method. The converter includes to merit of power factor correction (PFC) from sinusoidal control of input current. The switching behavior of control switches operates with soft switching by partial resonance, and then the proposed converter has high system efficiency with decrement of switching power loss. The input current waveform in proposed converter is got to be a sinusoidal form of discontinuous quasi-pulse row in proportion to magnitude of AC input voltage under the constant duty cycle switching. Therefore, the input power factor is nearly unity. The output voltage of the converter is regulated by PWM control technique. The discontinuous mode action of current flowing into inductor makes to simplify control method and control components. The proposed PFC Buck-Boost converter is analyzed to compare with the conventional PFC Buck-Boost converter. Some computer simulative results and experimental results confirm to the validity of the analytical results.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.1
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• pp.99-105
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• 2019

OBC for battery charging of electric vehicles mainly consist of two stages including PFC circuit and isolated DC-DC converter circuit. In general, a non-isolated boost converter is used as the PFC circuit, and a resonant converter capable of ZVS (zero voltage switching) is used as the isolated DC-DC converter. In this paper, we propose an OBC composed of isolated current-fed type PFC circuit and buck DC-DC converter. The proposed OBC is easy to configure the circuit and controller, and can cope with a wide output range. In order to verify the validity of the proposed circuit, a prototype 3.3 ㎾ class prototype was fabricated. As a result, the maximum efficiency and the maximum power factor of 99.2% were confirmed under the operational stability and rated load conditions at the output voltage of 150V ~ 400V.

• Journal of the Korea Society of Computer and Information
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• v.28 no.12
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• pp.231-238
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• 2023

For boost PFC (Power Factor Correction) converters, various control methods are being studied to achieve unity power factor and low THD (Total Harmonic Distortion) of AC input current. Among them, average current mode control, which controls the average value of the inductor current to follow the current reference, is the most widely used. However, nowadays, as advanced digital control becomes possible with the development of digital processors, predictive control of boost PFC converters is receiving attention. Predictive control is classified into predictive current mode control, which generates duty in advance using a predictive algorithm, and model predictive current control, which performs switching operations by selecting a cost function based on a model. Therefore, this paper simply explains the average current mode control, predictive current mode control, and model predictive current control of the boost PFC converter. In addition, current control under entire load and disturbance conditions is compared and analyzed through simulation.

• Journal of Power Electronics
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• v.15 no.5
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• pp.1168-1177
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• 2015

This paper presents a scheme to improve the line current distortion of power factor corrector (PFC) topology at the zero crossing point using a predictive control algorithm in both the continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The line current in single-phase PFC topology is distorted at the zero crossing point of the input AC voltage because of the characteristic of the general proportional integral (PI) current controller. This distortion degrades the line current quality, such as the total harmonic distortion (THD) and the power factor (PF). Given the optimal duty cycle calculated by estimating the next state current in both the CCM and DCM, the proposed predictive control algorithm has a fast dynamic response and accuracy unlike the conventional PI current control method. These advantages of the proposed algorithm lower the line current distortion of PFC topology. The proposed method is verified through PSIM simulations and experimental results with 1.5 kW bridgeless PFC (BLPFC) topology.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.7
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• pp.1349-1355
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• 2009

This paper is studied on a novel power factor correction (PFC) AC-DC converter of high efficiency by soft switching technique. The input current waveform in the proposed converter is got to be a sinusoidal form composed of many a discontinuous pulse in proportion to the magnitude of a ac input voltage under the constant switching frequency. Therefore, the input power factor is nearly unity and the control method is simple. The proposed converter adding an electric isolation operates with a discontinuous current mode (DCM) of the reactor in order to obtain some merits of simpler control, such as fixed switching frequency, without synchronization control circuit used in continuous current mode (CCM). To achieve the soft switching (ZCS or ZVS) of control devices, the converter is constructed with a new loss-less snubber for a partial resonant circuit. It is that the switching losses are very low and the efficiency of the converter is high, Particularly, the stored energy in a loss-less snubber capacitor recovers into input side and increases input current from a resonant operation. The result is that the input power factor of the proposed converter is higher than that of a conventional PFC converter. This paper deals mainly with the circuit operations, theoretical, simulated and experimental results of the proposed PFC AC-DC converter in comparison with a conventional PFC AC-DC converter.

• Journal of Power Electronics
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• v.15 no.6
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• pp.1547-1558
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• 2015

A predictive functional control (PFC) scheme for permanent magnet synchronous motor (PMSM) servo systems is proposed in this paper. The PFC-based method is first introduced in the control design of speed loop. Since the accuracy of the PFC model is influenced by external disturbances and speed detection quantization errors of the low distinguishability optical encoder in servo systems, it is noted that the standard PFC method does not achieve satisfactory results in the presence of strong disturbances. This paper adopted the Kalman filter to observe the load torque, the rotor position and the rotor angular velocity under the condition of a limited precision encoder. The observations are then fed back into PFC model to rebuild it when considering the influence of perturbation. Therefore, an improved PFC method, called the PFC+Kalman filter method, is presented, and a high performance PMSM servo system was achieved. The validity of the proposed controller was tested via experiments. Excellent results were obtained with respect to the speed trajectory tracking, stability, and disturbance rejection.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.2
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• pp.58-65
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• 2003

The conventional single phase PFC converter can control DC voltage to steady standard value but control system is system is complex and expensive and has rapidity problems because of controlled by detecting DC voltage, AC voltage and current. In order to solve those problems, this paper proposes senseless PFC converter circuit. The proposed circuit can control the whole system by detecting AC voltage waveform And it directly controlled DC output voltage by the controlled voltage value Kd(Ed/Ea). The fluctuation ratio of DC output voltage is changed by the circuit characteristics These characteristics are confirmed by some experimental results.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.4
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• pp.390-396
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• 2004

Recently, there have been Increasing demands for high power factor and low harmonic distortion in the current drawn from utility. The harmonic limits imposed by international standards. It need the PFC techniques in order to reduce line current harmonics and comply with the standards. The average current control method that is the most proper PFC control method in a switching power supply of middle and high power has been used mostly to PFC control method. However, the switching device of PFC circuit has frequently destructed at power return after instantaneous power interrupt. Therefore, this paper have verified the cause of this problems and proposed the solution through simulation and experiment

• Journal of IKEEE
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• v.16 no.4
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• pp.343-348
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• 2012

A 11b 100KS/s Algorithmic ADC for Digital PFC controller is proposed. The proposed Algorithmic ADC structure for 11bit resolution is based on a cyclic architecture to reduce chip area and power consumption. The prototype Algorithmic ADC implemented with a 0.18um 1Poly-3Metal CMOS process shows a SNDR 66.7dB and ENOB 10.78bits. And the current consumption is about 780uA at 100KS/s and 5V. The occupied active die area is $0.27mm^2$.