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123 results on '"Mannen, Tomoyuki"'

10. Full ZVS Achievement for DCM Grid-Tied Inverter With Improved Average Current Model and Considering Nonlinear Parasitic Capacitance

Author

Huang, Cheng, Mannen, Tomoyuki, and Isobe, Takanori

Abstract

This article proposes an improved current model for discontinuous current mode (DCM) grid-tied inverters operated with an off-time discrete control to improve its zero-voltage switching (ZVS) performance. The off-time discrete control can achieve ZVS by discretely adjusting the oscillation caused by the parasitic capacitance of semiconductor devices and the filter inductor during the zero current period of the DCM operation. However, the control method exhibits some errors, such as non-ZVS operation due to the nonlinearity of the parasitic capacitance. This article aims to provide a detailed modeling for inductor current and device voltage to improve the control accuracy and the ZVS performance of the off-time discrete control. The impact of the voltage-dependent parasitic capacitance on the resonance is analyzed in detail, and a calculation method for the oscillation period is proposed. A comparative study of the conventional and the proposed improved models is performed using the LTspice simulation. It confirms that the inductor current behavior can accurately be predicted by using the improved model and it significantly improves the control accuracy with the realization of ZVS. The feasibility of the control using the proposed improved average current model under various conditions was verified by the comparative experiments with a 1-MHz operated converter, which consists of gallium nitride high-electron-mobility transistor (GaN-HEMT) devices.

Published
2024
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34. Experimental Verification of a Model of Switching Transients Considering Device Parasitic Capacitance for the Loss Estimation of Soft-switching Power Converters

Author

Takanori Isobe, Hiroshi Tadano, Mannen Tomoyuki, Kaoru Takashima, and Daiki Tochigi

Subjects
010302 applied physics, Materials science, business.industry, 020208 electrical & electronic engineering, Electrical engineering, Hardware_PERFORMANCEANDRELIABILITY, 02 engineering and technology, Converters, 01 natural sciences, law.invention, Power (physics), Capacitor, Soft switching, Parasitic capacitance, law, 0103 physical sciences, Hardware_INTEGRATEDCIRCUITS, 0202 electrical engineering, electronic engineering, information engineering, Current (fluid), business, Communication channel, Voltage
Abstract

This paper discusses switching transients of MOS- FETs aiming at the switching loss estimation of the power converter operated under the zero-voltage switching condition. A simple model of switching is described. In this switching model, a part of the current flowing into channel of the device during turn-off generates the turn-off loss at the instant of the turn-off, and the rest of the current contributes to charge the parasitic capacitance; therefore, does not generate switching loss. This paper experimentally verifies that the current flowing into the channel of the device causes the switching loss. This verification was demonstrated by the converter operated under the zero- voltage turn-on condition. In addition, this paper proposes that the current flowing into the channel can be estimated from the experimental conditions and the static characteristics of the device. The accuracy of the proposed method was experimentally verified by using the device model which consists of a device and external capacitors connected between each terminals which simulate the parasitic capacitance of the device.

Published
2019

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