Showing papers by "Yoshishige Murakami published in 1995"

Characteristics of a 40 kVA three phase superconducting transformer and its parallel operation with a conventional transformer

Abstract: A 40 kVA three phase superconducting transformer has been developed and tested. From the test results, excellent voltage regulation of 0.3% with a pure resistive load was obtained. For application in a power system, parallel operation with a conventional power transformer using copper windings has been carried out. Although a superconducting transformer cannot continue to operate in case of quenching, the proposed parallel system can overcome the drawback and give an additional fault current limiting function. >

Power systemstabilizing control by a high speed phase shifter with an energy storage component

Abstract: A High Speed Phase Shifter (HSPS) using PWM inverters is paid much attention in FACTS (Flexible ac Transmission System). The HSPS presented here is composed of three sets of a single phase PWM inverter, transformers and ac filters for suppressing switching ripples of inverters. The proposed system has an energy storage component, therefore the system can control voltage phase freely. Design of the HSPS and experimental results of power system stabilizing control on a 10kVA model power transmission are presented.

Low-Frequency Raman Spectra of (BiPb)2Sr2CaCu2O8

Abstract: Low-frequency Raman spectra have been measured to clarify the relationship between low frequency modes and the incommensurate modulation in Pb doped Bi2Sr2CaCu2O8. The lines corresponding to the folded acoustic modes arising from the incommensu­rate modulation change in frequency rather abruptly at around nominal Pb composi­tion of 13%. This result is interpreted in terms of the change in the period of the modulation with the Pb doping.

Low temperature characteristics of power semiconductor devices

Abstract: Characteristics of various power semiconductor devices, such as MOSFETs, IGBTs, SCRs and power diodes are discussed in this paper based on experimental and 2-dimen-sional device simulation results for temperature higher than liquid nitrogen(77K).