The Transactions of the Institute of Electrical Installation Engineers of Japan
Online ISSN : 2433-4472
ISSN-L : 2433-4472
Volume 43, Issue 3
Displaying 1-2 of 2 articles from this issue
  • Ayumu Watanuki, Hironobu Yonemori
    2023Volume 43Issue 3 Pages 17-24
    Published: 2023
    Released on J-STAGE: April 10, 2023
    RESEARCH REPORT / TECHNICAL REPORT FREE ACCESS
    This paper discusses the development of an IH heating circuit using a current-resonant type AC-AC direct conversion method. The AC-AC direct conversion method can reduce the number of semiconductors through which the current passes compared to the conventional (indirect conversion) method, leading to a reduction in losses. Although several similar methods have been proposed in previous studies, the method we propose consists of only two coils, two capacitors, and four semiconductor devices, and is characterized by its simple structure that contributes to miniaturization. In this paper, we clarified the circuit design method and heating characteristics of the developed AC-AC direct conversion circuit. As a conclusion, it was shown that the heating efficiency is comparable to that of existing products, and further improvement in efficiency can be expected.
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  • Takuma Endoh, Kazutaka Itako
    2023Volume 43Issue 3 Pages 25-31
    Published: 2023
    Released on J-STAGE: April 10, 2023
    RESEARCH REPORT / TECHNICAL REPORT FREE ACCESS
    Polymer Electrolyte Fuel Cell (PEFC) is fuel cells which have low operating temperatures and are easy to miniaturize. Currently, a development of hydrogen infrastructure is being considered as a national initiative, and PEFCs are also attracting attention. However, due to a high cost of hydrogen, the running cost is high compared to other forms of power generation. So we previously proposed the MEPT (Maximum efficiency point tracking) control system, which is a highly efficient control system to reduce hydrogen consumption in fuel cells. However, this system has a problem: the hydrogen flow meter causes the detection of the maximum efficiency point to take a long time, resulting in wasteful hydrogen consumption. To solve this problem, we propose a new MEPT control that does not need a flowmeter and has a fast response time, using a newly defined efficiency voltage Ve. In this paper, we compare the amount of hydrogen used to generate electricity for the maximum power control, the previously proposed MEPT control, and the new MEPT control. As a result, the new MEPT control reduced hydrogen consumption by about 17.7% compared to the maximum power control and by about 7.7% compared to the previously proposed MEPT control.
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