Yazar "Furukawa, Yudai" seçeneğine göre listele

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    Analysis of Sensorless Model Control DC-DC Converter in CCM
    (IEEE, 2016) Furukawa, Yudai; Watanabe, Shingo; Maruta, Hidenori; Matsui, Nobumasa; Colak, Lihami; Kurokawa, Fujio
    We have proposed the sensorless model control based on the static model equation of the dc-dc converter that is able to change the bias value corresponding to changes of the load current, the input voltage and output voltage. The sensorless model control can regulate the output voltage. On the other hand, the transient response of output voltage is not improved. Therefore, an improvement of the transient response is carried out by adding the transient improvement function which changes a bias value drastically for a short time at the start of the transient state. The purpose of this paper is to indicate the parameter setting of the transient improvement function that improves the transient response by the simulation analysis under changing the circuit condition.
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    A Consideration of Loss Component in Model Control DC-DC Converter
    (IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 2015-11-22) Furukawa, Yudai; Watanabe, Shingo; Matsui, Nobumasa; Kurokawa, Fujio; Çolak, İlhami
    Recently, the energy saving is required. It is necessary for the energy saving to operate the electric device in the sleep mode. Therefore, the output voltage rises abnormally because the dc-dc converter is required the operation in the discontinuous current mode. Therefore, we have proposed the model control using static model and strived for improvements. In the proposed method, the output voltage is stabilized because the operating point is changed. Therefore it does not depend on the integral coefficient in principle to perform wide output voltage stabilization range. Actually, the steady state deviation remains because the model equation includes the error in the analysis. The integral control compensates it. In this paper, the static model equation and integral coefficient in the proposed method are considered based on the output voltage stabilization range.
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    A Consideration of Signal Frequency Detector in Digital Peak Current Mode DC-DC Converter
    (IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 2015-11-22) Furukawa, Yudai; Maeda, Shusuke; Tsuruoka, Shunsuke; Kurokawa, Fujio; Eto, Haruhi; Çolak, İlhami
    The purpose of this paper is to reveal the designing of the static characteristic of the digital peak current mode dc-dc converter using a voltage controlled oscillator (VCO). In the proposed method, it is able to sample the reactor current by using the VCO and the delay circuit. The improvement of the dynamic characteristic and the analysis of the proposed method have already been revealed. However the design method in the static characteristic of the proposed method has not been clear. In this paper, the analysis about the resolution of the output voltage is revealed for the designing of the proposed method in static characteristic. The change of the output voltage against the change of the delay time in the signal frequency detector is confirmed by comparing the analysis result and simulation results. Furthermore, the effect, which the signal frequency detector gives to the output voltage in the transient state, is discussed.
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    A Consideration of Transient Response for Sensorless Model Control DC-DC Converter
    (IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 2015) Furukawa, Yudai; Hirotaki, Shota; Watanabe, Shingo; Kurokawa, Fujio; Matsui, Nobumasa; Çolak, İlhami
    The purpose of this paper is to discuss a current prediction algorithm for sensorless model control dc-dc converter. In the proposed method, the sensing resistor for the current detection is eliminated by predicting the output current. The output current is predicted from the equation of the relationship between the output and input voltage in the static state using the duty ratio and the output voltage. The predicted output current is substituted the static model. Two different equations according to the operation mode of the dc-dc converter are used for the current presumption. They should be switched smooth and seamless for the output current prediction.
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    Digital PID Based Two-Compensator for DC-DC Converter
    (IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 2015) Furukawa, Yudai; Kurokawa, Fujio; Çolak, İlhami
    The purpose of this paper is to present the performance characteristics of the digital PID based two-compensator for the dc-dc converter. Authors have already presented a fast PD control method, which can reduce the influence of the delay time. In this paper, the transient characteristics of output voltage are confirmed in the simulation when the sampling frequency of the PID control is slowed down. As a result, the tendency of the transient characteristics of output voltage is revealed. Therefore, the slower sampling frequency of PID control can be applied to the dc-dc converter compared with the conventional PID control.
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    Digitally Proportional Gain Varying Method for DC-DC Converter
    (IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 2015) Furukawa, Yudai; Shirakawa, Takuya; Kurokawa, Fujio; Çolak, İlhami
    The purpose of this paper is to propose a digitally proportional gain varying method for dc-dc converter. In the proposed method, the proportional gain is set to a small value in the steady state and is changed to a large value over stability limit for only a short time in the transient state. Using the proposed method, the transient response can be improved while the dc-dc converter system is kept in stable. Compared with the conventional PID control, the undershoot and the convergence time are improved by 69% and 75%, respectively. Furthermore, the capacitance of output smoothing capacitor must be set to a large value to maintain the stability of system when the control gain is set to a very large value. However, that can be reduced because the very large gain is set for only a short time to improve the transient response in the proposed method. Therefore, the miniaturization of main circuit can be expected.
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    Dynamic Characteristics Analysis of DC-DC Converter for Server Using Digital Current-Frequency Detector
    (IEEE, 2016) Furukawa, Yudai; Nibu, Shintaro; Maruta, Hidenori; FujioKurokawa; Hirose, Keiichi; Colak, Ilhami
    The purpose of this paper is to analyze the dynamic characteristics of proposed digital peak current mode dc-dc converter. The waveforms of the output voltage and the reactor current are derived by the small signal analysis. They are compared with simulation results assuming an actual large amplitude operation. It is confirmed that the tendency of the transient response is indicated based on the analysis results. The experimental result of the proposed method shows the validity of the proposed method and a gradual response is obtained by an improvement of the stability of dc-dc converter. Consequently, the proposed method can be a solution of implementing the peak current mode control in digital.
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    Improvement for Fast Response of Current Sensorless Model Control DC-DC Converter
    (IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 2016) Furukawa, Yudai; Maruta, Hidenori; Watanabe, Shingo; Kurokawa, Fujio; Matsui, Nobumasa; Çolak, İlhami
    The switching power supply is required the wide load range operation for the energy saving. In such a situation, the output voltage must be regulated. The model control is able to regulate the output voltage, because the bias value is varied depending on the static model equation. Thus, it is effective for switching power supply to implement the model control. The existing sensorless model cannot have a quick response. The purpose of this paper is to improve the transient response of the sensorless model control dc-dc converter by setting the parameter of the function that changes the operating point for a short time at the start of the transient state. It suppresses the undershoot of output voltage. The validity of the proposed method is confirmed by comparison with existing model control method and the proposed sensorless model method.
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    Improvement in Transient Response of Fast P Control DC-DC Converter with Static Model
    (IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 2015-11-22) Furukawa, Yudai; Watanabe, Shingo; Kurokawa, Fujio; Eto, Haruhi; Matsui, Nobumasa; Çolak, İlhami
    The purpose of this paper is to propose the digital control method that is comprised of the fast P control and model control for an improvement of the transient response of the dc-dc converter. The electronic devices are required the operation in the standby mode and the quick return to the active mode. The fast transient response of the dc-dc converter in such condition is important. In this paper, the fast P control is combined with the model control. Therefore, the transient response in such situation is improved because the operating point is optimized according to the load current. From the results, in the case of the load step from DCM to CCM, the undershoot and the convergence time are improved by about 80%.
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    A New Quick Response Digital Control DC-DC Converter with Dynamic Unstable Gain
    (IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 2015-11-22) Furukawa, Yudai; Shirakawa, Takuya; Kurokawa, Fujio; Eto, Haruhi; Çolak, İlhami
    In this paper, we present a new quick response digital control dc-dc converter based on a dynamic unstable gain to improve transient response. In the proposed method, the proportional gain is set to the small value in the steady state and the large value over the stability limit for only a short time in the transient state. Compared with the conventional PID, the undershoot, the overshoot and convergence time are improved by 48%, 71% and 84%, respectively. Generally, when the control gain is set to very large value, the capacitance of output smoothing capacitor must be set to large value simultaneously to maintain the stability of system. That can be reduced and the miniaturization of main circuit can be expected because the very large gain is set for only a short time to improve the transient response in the proposed method.
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    Performance Characteristic of Digital Peak Current Mode Control Switching Power Supply
    (IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 2015-09-08) Furukawa, Yudai; Maeda, Shusuke; Kurokawa, Fujio; Çolak, İlhami
    The purpose of this paper is to discuss performance characteristic of digital peak current mode control switching power supply. The proposed method can capture the peak current value in real time by using the voltage controlled oscillator (VCO), the programmable delay circuit and the signal frequency detector. Its transfer function is derived analytically. Also, the frequency characteristics are revealed using the loop transfer function in the case of different voltage control loop gains. In addition, its gain margin and phase margin are discussed. Furthermore, the transient responses of proposed method are compared with the conventional voltage mode control in the simulation and the experiment.
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    Performance Characteristics of Digital Current Detector in DC-DC Converter
    (IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 2015) Furukawa, Yudai; Maeda, Shusuke; Kurokawa, Fujio; Çolak, İlhami
    The purpose of this paper is to present a performance characteristics of digital current detector in dc-dc converter. The digital peak current mode control dc-dc converter using the voltage-controlled oscillator (VCO) has already proposed. The peak current is detected by using VCO in the proposed method. The gain of amplifier in the current detector affects to the input voltage range of VCO. Also, it affects the transient response. They are discussed by analysing and simulation.