Shoji Fukuda

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This paper proposes a new arrangement and new control strategies for a hybrid multilevel converter, aiming at a high-power high-efficiency converter system being free from harmonic distortion. The strategies enable one to expand the adjustable output voltage range up to 100% by keeping a very low harmonic distortion of the output voltage. The(More)
A current-source active power filter that consists of a current source active filter (AF) and second-order high-pass filters (HPFs) is described. A pulse-width-modulation (PWM) control method is described. It is shown that excellent total filter performance over a wide frequency range is obtained with a low AF switching frequency. The design criteria for AF(More)
Diode rectifiers have been widely used for an ac-to-dc converter. One of their problems is that they include large harmonic contents in its input current. A 12-pulse diode rectifier is useful for reducing them, but it still includes the (12m/spl plusmn/1)/sup th/ (m: integer) current harmonics in its input. In order to further reduce the input current(More)
A sinusoidal pulsewidth-modulation (PWM) technique suitable for single-chip-microprocessor-based control is described. The scheme can be considered as a digital alternative to the analog subharmonic method (SHM) in the sense that online real-time PWM control is possible, synchronization between carrier wave and signal wave is unnecessary, and low-order(More)
A description is given of a sinusoidal pulsewidth-modulation (PWM) method for a current-source rectifier and inverter. As the DC current flows continuously, a DC current pass must exist in the rectifier and inverter circuit. Accordingly, the subharmonic method, in which the PWM pulse pattern is produced by comparing a triangular carrier wave with a(More)
To guide reconstruction of scaphoid non-union, we attempted to create full-scale models of the scaphoid by three-dimensional computed tomography (3D CT) of the healthy side. In this study, we obtained 3D scans of 51 cadaveric hands and studied the difference in morphology between genders and between the left and right sides. The major axis length on a fixed(More)
Three-phase thyristor rectifiers have been used in industries for obtaining a variable dc voltage, but they have a problem of including large lower-order harmonics in the input currents. For high-power applications, a 12-pulse configuration is useful for reducing the harmonics, but it still includes the (12 m plusmn1)th (m: integer) harmonics. In order to(More)
Right aortic arch with Kommerell's diverticulum is a very rare situation. Surgical treatment is recommended for symptomatic patients or asymptomatic patients with a large diverticulum. However planning the strategy of operation is difficult without a 3D imaging. We report a case of a 57-year-old man with right aortic arch, Kommerell's diverticulum, and(More)