In recent years, energy management has been required to achieve carbon neutrality and to address energy issues. Since electric energy management requires knowledge of electrical machinery, engineers in this field are expected to be developed. On the other hand, in situ experiments are effective in verifying the knowledge learned in class in engineering studies. However, electrical machinery is large and heavy, which makes it difficult to carry it into the classroom for in situ experiments. In this study, remote-control experimental equipment are developed that can remotely operate electrical machinery in the laboratory and verify its behavior in the classroom. The two developed remote-control experimental equipment are for speed control of DC motors and no-load testing of three-phase synchronous generators. This remote-controlled experimental equipment are suitable for observing the behavior of the machines in class because the experiments are carried out automatically and in a short time by OpenPLC. A questionnaire survey on the developed remote-controlled experimental equipment confirmed its potential to improve students' interest in learning and their level of understanding.

This study introduces a novel instructional activity conducted in an information design class, where students creatively constructed lamp shades embedded with simple electrical circuits. The lesson began with foundational concepts in electrical systems, including the principles of direct current (DC) and alternating current (AC). Students then progressed to assembling blinking circuits and investigating energy conversion mechanisms using model motors. The curriculum advanced to practical applications such as DC-to-AC conversion, deepening their understanding of electrical engineering principles. As a culminating challenge, students attempted to illuminate a 100V incandescent bulb using batteries, prompting inquiry into voltage, current, and energy efficiency. Throughout the course, emphasis was placed on hands-on experimentation, interdisciplinary thinking, and design-based problem solving. To assess students' psychological engagement and adaptation to this learning environment, a school adaptation scale was administered. The results provided insights into students' emotional and cognitive responses to the project-based approach, underscoring the potential of integrated STEM education to enhance motivation and school satisfaction. These findings suggest that incorporating creative electrical design into information education can promote both technical proficiency and positive psychological outcomes.

A method for estimating the countermeasure effect using a common-mode filter (hereafter referred to as CMF effect) is proposed, based on the concept of disturbance power propagation. The method was applied to the radiated electric field (hereafter referred to as E-field) strength from cables, and analysis using the chain parameter matrix showed that the CMF effect on the E-field could be estimated from the CMF effect on the CM (Common-Mode) current at the cable input. A measurement using a test setup according to CISPR 25 indicated that the correlation coefficient between the CMF effect on the E-field and the CMF effect on the CM current was more than 0.97 in the frequency range from 31 to 239MHz. The CMF effect on the CM current was measured in a regular laboratory, and the correlation coefficient was more than 0.95. In addition, the CMF effect on the CM current was calculated using the chain parameter matrix, and the correlation coefficient was more than 0.94. These results showed that the proposed method can efficiently estimate the CMF effect on the E-field from an experiment in a regular laboratory and through calculation.

The internal magnetic domain structures near the laser irradiation area in a grain-oriented electrical steel sheet were observed by a magnetic microscope utilizing the magnetooptical effect called x-ray magnetic circularly polarized emission, in order to understand the magnetostriction characteristics of grain-oriented electrical steel. In the dc magnetized state, the domain structures consisted of main domains that were separated by 180° domain walls and closure domains. The magnetization component perpendicular to the sheet plane were observed in the regions adjacent to the main domains. The observed closure domains directly below the laser irradiation area showed magnetization component perpendicular to the sheet plane and elongated along the normal direction. The width of closure domains in the internal layer was wider than that in the surface layer of the steel sheet.

Motors are used in a wide range of the drive region from low speed to high speed. Magnetic properties of electrical steel sheets are used as core materials for motors, change by applying the stress. When the motor is driven, the stress by the centrifugal force is applied the rotor core. Therefore, it is important to understand the relationship between the stress and magnetic property. In this paper, a measurement device of the magnetic properties of ring core under the centrifugal force will be developed. At first, we evaluated the stress components in the ring core under the centrifugal force by theoretical stress analysis. In addition, we will fabricate a new device to apply centrifugal force and measure the magnetic properties of a non-oriented electrical steel sheet under centrifugal force.

Partial discharge (PD) has been analyzed for a long time, but it is still difficult to understand fully because PD strongly depends on experimental conditions. To understand PD characteristics, we attempt to directly measure the fast-PD current waveforms of nanosecond order. We make the PD measurement circuit length shorter to get PD waveforms correctly. The total length of our new PD current-flow circuit is reduced to less than 150 mm. We use simple needle-plane electrodes with small discharge gaps of 0-150 µm. The needle diameter used is 1 mm with a tip radius of 300 µm. AC peak voltage of 2 and 3 kV_p at 50-1000 Hz are applied to polymer films of polyimide, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, cross-linked polyethylene, low-density polyethylene, and low-density polyethylene with antioxidant. The PD current peak time exhibits approximately 5 ns for both positive and negative pulses, and the pulse width at half height of the peak value is 5-15 ns. Nuclear magnetic resonance analyses suggest that the current wave form differences may be due to the dipole movement affected by the trapped charges.

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.