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5. A Partial Active Gate Control for Improvement of a Trade-Off Relation Between Surge Voltage and Efficiency in a Three-Phase Inverter

Author

Pham, Van-Long, Obara, Hidemine, and Hata, Katsuhiro

Abstract

This paper presents a control method of fully digital active gate drivers in a three-phase inverter to simultaneously realize surge voltage reduction and efficiency enhancement. Generally, the surge voltages of power devices occur at each switching, and they are determined depending on the operation mode including switching schemes and three-phase current directions. The active gate control technology can change the gate drive current and switching speed in detail in every gate control period which is usually quite shorter than the switching period, and it contributes to suppressing surge voltages. However, offline optimization of the active gate driving pattern considering operating conditions is usually complicated and takes a long time to find a better gate pattern. In this paper, a partial active gate control method without detailed pattern optimization is proposed. In the proposed method, the active gate driving patterns of fully six gate drivers are suitably changed according to the phase angle of the three-phase current to minimize the highest surge voltage and the switching loss in a fundamental period without any optimization. A prototype of the three-phase inverter using a 6-in-1 SiC power module and six digital active gate driver ICs was developed to verify the improvement effect of the proposed active gate control. Based on an analysis result of operation modes and surge voltages in the three-phase inverter, a suitable active gate control method was clarified considering each operating region in one ac cycle. It has been verified that the proposed partial active gate control contributes to reducing the highest surge voltage, fixing a high efficiency.

Published
2024
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12. Survey of 99.9% Class Efficiency DC‐AC Power Conversion and Technical Issues.

Author

Kawamura, Atsuo, Miguchi, Yasuhiko, Setiadi, Hadi, and Obara, Hidemine

Subjects
WIDE gap semiconductors, GALLIUM nitride, DC-AC converters, ELECTRIC current rectifiers
Abstract

This study provides a survey overview of the literatures with the goal of maximizing the efficiency of DC‐AC power conversion from an engineering science perspective. With the advent of wide band gap power semiconductors, the published literature on realizing high efficiency DC‐AC converters has increased. Therefore, a literature survey of high‐efficiency DC‐AC inverters was first conducted. We demonstrated the importance of the measurement accuracy in measuring high efficiency losses, and then presented the literature on new measurement methods, as well as examples of analysis of the breakdown of these losses. Furthermore, we reviewed the literature on high‐efficiency inverters. We presented measurement data (99.83%) on an inverter with a high efficiency energy conversion system circuit topology using Silicon Carbide (SiC) and Gallium Nitride (GaN) devices to demonstrate how the procedure was used to achieve loss minimization. We summarized the challenges hindering high efficiency. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Published
2023
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42. Design for nonlinear current reference deadbeat control for boost converter

Author

Mushi, Aviti, Nagai, Sakahisa, Obara, Hidemine, and Kawamura, Atsuo

Subjects
Engineering, Settling time, business.industry, 020208 electrical & electronic engineering, 02 engineering and technology, Converters, Inductor, Compensation (engineering), Nonlinear system, Control theory, Boost converter, 0202 electrical engineering, electronic engineering, information engineering, Electronic engineering, DC-DC boost converter, Digital control, Disturbance rejection, business, Voltage
Abstract

This paper describes a design for fast and robust nonlinear deadbeat control for boost DC–DC converters. Nonlinear current reference deadbeat control is derived based on nonlinear state equation of the converter. Load disturbance compensation is implemented thus forming a new robust nonlinear controller. Both experiments and simulations of boost converter with input 12 V, output 20 V, load 4 Ω and 100 kHz sampling frequency, confirmed the voltage command tracking capability 266 μs settling time, and also disturbance rejection 1.20 ms recovery time. The method is applicable to boost converters of various applications.

Published
2017

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