Yoshihisa Uriu

  • Citations Per Year
Learn More
The authors have been studying a novel type of superconducting fault current limiting reactor (SCFCLR). The SCFCLR is a reactor which has three superconducting windings with the same numbers of turns wound on a single iron core. An equivalent circuit is proposed for the SCFCLR. Using this equivalent circuit, the leakage reactances of the SCFCLR were(More)
This paper presents a tool, which is implemented on the MATLAB/Simulink environment realizing a user friendly GUI system with object oriented configuration, to analyze the dynamical behavior of industrial electrical power system with a customerpsilas gas turbine power plant. A model consisting of a gas turbine system including the steam flow, a synchronous(More)
Industrial power systems with industrial power generation plant have very complicated structures. In addition, these systems are usually interconnected with utilities, that is, disturbances in the utility network affect the operation and the protection coordination in industrial systems. Therefore, modeling and analysis technique for industrial power(More)
Recently, the trend of control engineering changes from classical control theory to modern control theory, and also analogue to digital with times. But, even now parameter adjustment in generator excitation control has been often carried out by the classical loop-shaping method using a Bode diagram. Modern control theory has seldom been used in practice due(More)
It's well known that when the rated terminal voltage is suddenly impressed to the stationary state squirrel-cage induction motor, a vibratory transient torque appears. However, this fact is not unexpectedly considered by many industrial users. We considered and discussed about the induction motor driven turbo compressor in the past. And we also try to(More)
This paper presents a brief summary of issues on industrial customer's electrical power systems and an approach to analyze the transient behavior of a system with the group of self-generators, substations and many induction motors. Power oscillations and voltage recovery performance after some contingencies are recognized as typical issues on customer's(More)
Recent years, we come to be seen world wide that customers install private electric generator, because it enforces that deregulation of a power industry and electric power liberalization. Particularly, small capacity gas-turbine generation system is more than diesel generation system about exhausts gases and a floor space per capacity. Additionally, it is(More)
For quench detection or the monitoring of a superconducting magnet the authors introduce a fuzzy theorem for a new monitoring system to obtain overall diagnostic information synthesized from a number of fundamental detection items. The present operating condition of a superconducting magnet is given as a numerical amount. This numerical index (dangerous(More)
For the monitoring of large superconducting magnets like those in a nuclear fusion reactor, it is necessary to make decisions integrating data gathered by numerous sensors. Here, the authors propose such a new method using a fuzzy theorem. This method utilizes a number of variables such as fundamental membership functions. These fundamental membership(More)
In the LHD (Large-scale Helical Device) system, superconducting coils are fed by superconducting bus-lines. For sound operation of the LHD, a reliable quench detection system of the superconducting bus-lines is essential. The first difficulty for the quench detection is the lack of the voltage monitoring leads closely running along the conductors. The(More)