Kabushiki Kaisha Toshiba

Nippon Steel Sumitomo Metal Corporation

Kazuto Kawakami

Masafumi Miyazaki

Akio Hirata

Hideaki Yamamura

Takeshi Kubota

Kazuhiro Satoh

Takeaki Wakisaka

Yousuke Kurosaki

Kazumi Mizukami

Kosaku Ichikawa

Jun Takahashi

Toshiaki Oka

Suzuo Saito

Tadao Mose

Teruo Nakagawa

Kohsaku Ichikawa

Yukinori Tsuruta

Haruo Ohmori

Tsugunori Kuga

A non-oriented electrical steel sheet comprising, Si: not less than 1.0 mass % nor more than 3.5 mass %, Al: not less than 0.1 mass % nor more than 3.0 mass %, Ti: not less than 0.001 mass % nor more than 0.01 mass %, Bi: not less than 0.001 mass % nor more than 0.01 mass %, wherein Expression (1) is satisfied when a Ti content (mass %) is represented as [Ti] and a Bi content (mass %) is represented as [Bi]: [Ti]&#x2266;0.8&#xd7;[Bi]+0.002 . . . (1).

Non-oriented electrical steel sheet and manufacturing method thereof

In a non-oriented electrical steel sheet, Si: not less than 1.0 mass % nor more than 3.5 mass %, Al: not less than 0.1 mass % nor more than 3.0 mass %, Ti: not less than 0.001 mass % nor more than 0.01 mass %, Bi: not less than 0.001 mass % nor more than 0.01 mass %, and so on are contained. (1) expression described below is satisfied when a Ti content (mass %) is represented as [Ti] and a Bi content (mass %) is represented as [Bi].[Ti]&#x2266;0.8&#xd7;[Bi]+0.002&#x2003;&#x2003;(1)

A non-oriented electrical steel sheet, containing: C: 0.01 mass % or less; Si: 1.0 mass % or more and 3.5 mass % or less; Al: 0.1 mass % or more and 3.0 mass % or less; Mn: 0.1 mass % or more and 2.0 mass % or less; P: 0.1 mass % or less; S: 0.005 mass % or less; Ti: 0.001 mass % or more and 0.01 mass % or less; N: 0.005 mass % or less; and Y: more than 0.05 mass % and 0.2 mass % or less, with the balance being iron and inevitable impurities.

Non-oriented electrical steel sheet

A gas charge container includes a sample holder which holds a needle-shaped material, a deutrium gas supply portion which charges a deutrium gas into the needle-shaped material held by the sample holder, and a heating portion which heats the needle-shaped material held by the sample holder. The needle-shaped material is cooled by blocking the heat generated by the heating portion after the needle-shaped material is heated by the heating portion.

Gas charge container, atom probe apparatus, and method for analyzing hydrogen position in material

The IGBT drive signal to a power converter comprising power semiconductor elements, such as IGBT, is supplied by a PWM controller which performs pulse width modulation of voltage references. A DC offset voltage Vd is generated by a DC offset generator in accordance with the output frequency f and output phase &thgr;, and this voltage Vd and the voltage references are added together by adders and supplied to the PWM controller to form IGBT drive signals. Thereby, it is possible to reduce the amount of loss generated by the power semiconductor elements used in the control device of a power converter for converting DC voltage to AC voltage, or AC voltage to DC voltage.

Control device for power converter

In a power conversion device comprising an AC filter for harmonic current suppression having a combination of at least some of a reactor, capacitor and resistance and a power conversion circuit that converts AC power into DC power or DC power into AC power and is connected to an AC power source through AC filter by providing: voltage reference calculation means (unit) that calculates and outputs a voltage reference corresponding to the voltage that is to be output by the power conversion device main unit; current detection means (unit) that detects and outputs current flowing through a prescribed location between AC power source and power conversion circuit and voltage reference correction means (unit) that uses the output from current detection means (unit) as a voltage reference correction signal to correct the voltage reference that is output from voltage reference calculation means (unit) resonance of the AC filter for harmonic current suppression is suppressed without employing a damping resistance for resonance suppression.

Power conversion device

A multiple inverter system of the present invention is disclosed. It includes a plurality of input transformers having secondary windings and a plurality of unit inverter cells connected in series at n stages to compose respective phases and supply the electric power to a multiple phase load in combination with the input transformers. The input transformers have 3n sets of three-phase windings at the secondary side and the secondary windings of the transformers, which are out-of-phase at each phase, are connected to unit inverter cells of each phase at the n-th stages. Further, the present invention is provided with a bypass switch control to melt a fuse that is applicable to a unit inverter given with a circuit closing command by giving this circuit closing command to a bypass switch corresponding to applicable unit inverters in response to an operation abnormality detector and a DC abnormality detector.

Multiple inverter system

A power converter having at least a pair of voltage drive switching elements, which comprises a gate control circuit, the gate control circuit comprising a detecting section for detecting at least one of a set of device parameters and a set of electric parameters of the voltage drive switching elements, a monitoring section for monitoring at least one of states of turn-on and turn-off of the voltage drive switching elements based on the at least one of a set of device parameters and a set of electric parameters of the voltage drive switching elements detected by the detecting section, and a control section for controlling a gate of the voltage drive switching elements based on a monitoring result of the monitoring section.

Power converter with voltage drive switching device monitored by device

A gate drive circuit for a voltage-driven type power switching device, including a control device for generating a gate voltage for the voltage-driven type power switching device, and a correction device connected to the control device for receiving the gate voltage and for correcting an effect of a magnetic flux resulted from a main circuit current flowing in the voltage-driven type power switching device applied to the gate voltage to generate a corrected gate voltage. The corrected gate voltage is applied to a gate of the voltage-driven type power switching device.

Gate drive circuit for voltage-driven type power switching device

This inverter system is directed to an inverter system in which a plurality of inverters adapted for generating output voltages corresponding to a voltage reference and a frequency reference respectively given through voltage controllers and frequency controllers are operated in parallel. In this inverter system, a difference between an output current of a corresponding inverter and output currents of other inverters is detected. By implementing the d-q axis orthogonal coordinate transform processing to that current difference, a first correction signal relating to the frequency of an output voltage of that inverter and a second correction signal relating to the amplitude of the output voltage thereof are provided.

Current sharing control in a parallel inverter system

An off-gate circuit for a GTO thyristor comprises a power source for supplying current to the circuit at a predetermined voltage, and a switching circuit connected to the power source for supplying off-gate current to the GTO thyristor at least two different current rates.

Off-gate circuit for a GTO thyristor

A turbine helper drive apparatus has an induction motor coupled to a turbine, and a power converter for power-controlling the motor. Part of the load of the turbine is shared by the motor in accordance with preset power for power control, so that auxiliary drive to compensate for the insufficient capacity of the turbine is performed and cheaper, late-night electric power is effectively utilized.

Growing community of inventors

Tokyo, Japan

Kazuto Kawakami