Language：English   Publisher：The Institute of Electrical Engineers of Japan  

In this study, a photovoltaic (PV) system is proposed with a capacitor directly connected between a PV module and a power converter. In the proposed system, the electrical energy output by the PV module is increased by receiving the discharge power of the additional capacitor without any losses other than itself and thus compensating for reduced power output when the intensity of the solar radiation decreases. However, the additional capacitor reduces the speed with which the operating point of the PV system can vary, which causes the conventional hill-climbing method to fail to track the maximum power point (MPP). Therefore, a modified hill-climbing method is also proposed that makes no errors in searching for the MPP. The proposed approach creates reference values based only on the difference in the output power of the PV module due to the variation in the operating point by correcting for fluctuations in the intensity of solar radiation. This allows the PV operating point to track to the MPP. The results of an experimental evaluation and a simulation show that the proposed method improved the output electrical energy of a PV system by 7.50% compared to the conventional method on a sunny day. Moreover, it also improved the output electrical energy of the system by 44.5% on a cloudy day.

DOI： 10.1541/ieejjia.20250669

CiNii Research

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Language：Japanese   Publisher：The Institute of Electrical Engineers of Japan  

This letter proposes an equivalent circuit model for tracking phenomena in power plugs. Tracking-related fires and contact point heating are serious safety concerns. To enable early detection using current and voltage measurements, understanding the progression mechanism of tracking phenomena is essential. Experiments simulating tracking fires were conducted, and the proposed circuit reproduces key waveforms of arc discharge and insulation change, accounting for dry-band formation and carbon track growth. Results showed that the model can reproduce the main features of tracking phenomena and may be useful for future studies on early detection of tracking-related fires.

DOI： 10.1541/ieejfms.146.112

CiNii Research

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Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical Engineers of Japan (IEE Japan)  

DOI： 10.1541/ieejjia.24004818

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Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical Engineers of Japan (IEE Japan)  

DOI： 10.1541/ieejjia.l24000622

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Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

A boost converter is used in various applications to obtain a higher voltage than the input voltage. One of the current main circuit systems for hybrid electric vehicles (HEVs) is a combination of a two-phase boost converter (parallel circuit) and a three-phase two-level inverter. In this study, we focus on the boost converter to achieve even higher efficiency and propose an interleaving scheme for a boost converter suitable for a three-level inverter (series circuit). The series circuit has two capacitors connected in series and makes it suitable as a power supply for a three-level inverter. We analyze the input current ripple of the series and parallel circuit in order to show the superiority of the series circuit. Furthermore, we propose a novel output voltage control strategy using an optimal regulator, namely a Linear Quadratic Regulator (LQR), for the series circuit. As a result, we found the input current ripple of the series circuit is smaller than the parallel circuit and demonstrated the superiority of the series circuit. The simulation and experimental results show the effectiveness of the proposed interleaving scheme and optimal regulator.

DOI： 10.3390/wevj14010007

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J-GLOBAL

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J-GLOBAL

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Publisher：IEEE  

DOI： 10.1109/icrera66237.2025.11283978

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Publisher：IEEE  

DOI： 10.1109/ecce-europe62795.2025.11238774

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