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Your search keyword '"Tamai, Shinzo"' showing total 23 results
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23 results on '"Tamai, Shinzo"'

1. Control and performance of a self-commutated GTO converter operating in parallel with line-commutated thyristor converters

Author

Tamai, Shinzo, Murakami, Shotaro, Uchida, Ryohei, and Akagi, Hirofumi

Subjects
Thyristors -- Research, Business, Computers, Electronics, Electronics and electrical industries
Abstract

Recently, static var generators (SVGs) or static synchronous compensators based on self-commutated converters have been put into practical use for the purpose of compensation for reactive power, power swings damping, and/or voltage control in power systems. The SVGs have also been applied to reduce voltage fluctuations appearing at high-speed train substations. When parallel resonance occurs between passive filters installed at a point of common coupling (PCC) and the power-system impedance existing upstream of the PCC, voltage/current harmonics are significantly amplified in the power system. This paper describes the control and performance for a self-commutated gate-turn-off (GTO) converter operating in parallel with conventional line-commutated thyristor converters. This hybrid power conversion system rated at more than dozens of MVA has an inductive load at the dc side. A bank of passive filters is connected not only for harmonic compensation of the line-commutated converters, but also as a constant leading reactive-power source. The GTO converter can control either leading or lagging reactive power so as to achieve unity power factor operation. In addition, it has the capability of damping out parallel resonance between the passive filters and the power-system impedance. This paper confirms the viability and effectiveness of the hybrid system by means of theory and computer simulation. Index Terms--Harmonics, line-commutated converters, parallel resonance, self-commutated converters, static synchronous compensator (STATCOM), static var generator (SVG).

Published
2004

9. Filter design of restraining over-voltage and bearing current in induction motor fed by PWM inverter

Author

Jiang Jianguo, Huang Lipei, Deng Wen, Lv Chuan, and Tamai Shinzo

Subjects
Engineering, Bearing (mechanical), business.industry, Mutual capacitance, law.invention, Inductance, Filter design, law, Overvoltage, Filter (video), Control theory, Electronic engineering, business, Electrical impedance, Induction motor
Abstract

PWM-inverter-induction-motor system will produce the over-voltage at the motor side and the strengthening of bearing current. R-C filter installed at the motor side is an effective method for restraining the over-voltage and bearing current. The method of choosing the parameters of filter is presented in the paper. The results of the simulations and experiments displayed in the paper proved the validity of the above method. The paper presented a simulation procedure, which can consider the mutual inductance and the mutual capacitance of the cables, and the test results of impedance frequency characteristic of several sets of induction motor.

Published
2003

19. Secondary Resistance Identification of Induction Motor Using a Model Reference Adaptive System and the Identification Characteristics.

Author

Sugimoto, Hidehiko and Tamai, Shinzo

Subjects
*INDUCTION motors, *ALTERNATING currents, *ELECTRIC resistance, *ELECTRICAL engineering
Abstract

Discusses secondary resistance identification of induction motor using a model reference adaptive system and the identification characteristics. Induction motor control in the secondary flux coordinate system and necessity of secondary resistance identification; Secondary resistance alternating current (AC) on the primary current in the secondary flux coordinate system; MRAS based secondary resistance identification; Simulation and experiments for studying the identification characteristics.

Published
1986
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21. Secondary Resistance Identification of an Induction-Motor Applied Model Reference Adaptive System and Its Characteristics

Author

Sugimoto, Hidehiko and Tamai, Shinzo

Abstract

Induction-motor torque is not accurately controlled when the estimated secondary resistance of an induction-motor model in a vector controller differs from the true secondary resistance. An algorithm which identifies the secondary resistance on-line is developed. The motor operating condition for secondary resistance identification, the stable identifier organization, and the experimental investigation confirming the identification algorithm performance are presented. The algorithm is based on the theory of model reference adaptive systems (MRAS). The proposed algorithm stably identifies the secondary resistance under any load and any speed when a sinusoidal signal is injected into the flux axis primary current. The vector controller adopting this algorithm controls motor torque accurately under any load and any speed.

Published
1978
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