Hitachi, Ltd.

Other

Shigeta Ueda

Mitsuyuki Hombu

Takashi Ikimi

Shuji Katoh

Hiromitsu Sakai

Tomomichi Ito

Kazuo Honda

Takashi Hotta

Kotaro Shimamura

Yasuo Matsuda

Akira Bando

Seiya Shima

Yoshitaka Takahashi

Takeki Ando

Hideaki Takahashi

Katsunori Suzuki

Hiromi Inaba

Yuichiro Morita

Sadao Hokari

Kazuhiro Imaie

Mitsuyasu Kido

Akiteru Ueda

Katsu Komuro

Takeshi Takehara

Kazuhiko Sasaki

Motoo Futami

Yoshio Sakai

Masaya Ichinose

Kazuji Yamada

Kiyoshi Nakamura

Hirokazu Suzuki

Hiroshi Nagase

Nobuyoshi Mutoh

Masahiro Nagasu

Koji Sakamoto

Hirokazu Inoue

Toshihiko Matsuda

Houng Joong Kim

Kim Houng Joong

Toshiaki Kurosawa

Yasuhiro Kiyofuji

Kazuo Suzuki

Toshimitsu Tobita

Masao Nakazato

Yasuo Osone

Mitsuyuki Honbu

Hironori Kodama

Nobuo Mitsui

Hidetoshi Aizawa

Kenzo Kamiyama

Yorito Jifuku

Yuuichiro Morita

Noboru Ogawa

Akira Maekawa

Hiroyasu Satou

Daisaku Morinaga

In a synchronization system adopted in a synchronous-multisystem control apparatus comprising a plurality of systems operating synchronously with each other at a fixed control period, the synchronous-multisystem control apparatus can be operated in a single-system mode in the event of failures occurring simultaneously in some of the systems. The synchronous-multisystem control apparatus employs a plurality of control circuits each provided for one of the systems. Any particular one of the control circuits comprises:

Synchronization system and synchronization method of multisystem control apparatus

A dynamo-electric machine has a stator with a primary winding and a rotor with a field magnet and a shaft. the field magnet includes a first field magnet having diferent polarity magnetic poles sequentially arranged in a rotation direction and a second field magnet having diferent polarity magnetic poles sequentially arranged in a rotation direction. The machine further has a mechanism for shifting the first and the second field magnets in axial and rotation directions.

Dynamo-electric machine having a rotor with first and second axially or rotationally displaceable field magnets

A semiconductor power converting apparatus including at least one series arrangement of MOS control semiconductor devices such as Insulator-gate Bipolar Transistors (IGBTs) or metal oxide MOS transistors which are respectively applied with a gate voltage under the control of corresponding a driver. The driver contains a supply line having a higher potential than a gate voltage of an IGBT coupled thereto when the IGBT is in a steady ON state, and is such that is causes an increase of the gate voltage of the IGBT in accordance with the current of the supply line when a potential difference between the power supply line and an emitter of the IGBT is constant and the collector voltage thereof exceeds a predetermined value under an ON state of the IGBT.

Semiconductor power converting apparatus

A power conversion apparatus has a circuit configuration in which a collector voltage of an IGBT is divided. It also has a unit which protects the IGBT against overvoltages applied to the collector by outputting a potential of a voltage dividing point to a gate of the IGBT. A case of a resistor on the high-voltage side of the voltage dividing point is fixed to an emitter potential of the IGBT.

Semiconductor power conversion apparatus

A gate driver is provided for controlling a gate voltage of each of a plurality of MOS control semiconductor devices, such as IGBTs or metal oxide MOS transistors, of a semiconductor power converter in which said MOS control semiconductors are connected in series with each other, the gate driver includes a power supply line having a higher potential than a gate potential on each of said MOS control semiconductor devices when in steady ON state, and an arrangement for supplying a current from the power source line to the gate of each of said MOS control semiconductors to increase the gate voltage of the MOS control semiconductor devices when a potential difference between said power supply line and an emitter of each of said MOS control semiconductors is constant and when a collector voltage of the MOS control semiconductor device exceeds a predetermined value under ON state of the MOS control semiconductor device.

Gate driver for MOS control semiconductor devices

Wind power generation system

A semiconductor electric power converter in accordance with the present invention comprises an arm consisting of an IGBT, a capacitor connected between a collector and a gate of said IGBT, and a gate circuit connected to the gate of said IGBT for controlling the switching operation of said IGBT, wherein a plurality of said arms connected in series are connected in parallel and each midpoint of said arms connected in of series is connected to a load. Thereby the impedance between the gate terminal of the IGBT and the gate circuit is decreased when the gate voltage is higher than the gate voltage command value or the impedance between the gate and the emitter of the IGBT is decreased when the collector voltage is high so that an electric charge stored in the gate is rapidly discharged.

Power conversion apparatus

Control electrode wirings which are led out from control electrodes over a number of chips built in a flat package and insulating members which are provided in order to insulate the control electrode wirings from main electrode wirings are also given function of positioning of the respective semiconductor chips in the flat package. Further, a one-piece control electrode wiring net is housed in the common electrodes of the package and the electrodes which are led out from the control electrodes of the respective semiconductor chips are connected to the net to simplify the processing of a large number of gate signal wirings.

Flat semiconductor device and power converter employing the same

In a synchronization system adopted in a synchronous-multisystem control apparatus including a plurality of systems operating synchronously with each other at a fixed control period, the synchronous-multisystem control apparatus can be operated in a single-system mode in the event of failures occurring simultaneously in some of the systems. The synchronous-multisystem control apparatus employs a plurality of control circuits each provided for one of the systems. Any particular one of the control circuits includes: a period-signal generating circuit for generating a period signal indicating a start point of a control period; a synchronization-reference selecting circuit for outputting a synchronization-reference signal by referring to period signals generated by the systems; and a control-period correcting circuit for correcting a control period of the particular system by forming a judgment on a synchronization shift of the period signal generated by the particular system from the synchronization-reference signal and keeping the control period as it is in case the synchronization-reference signal is not generated.

A power converter system includes: a circuit breaker having one terminal connected to a power system and another terminal connected to a load; a transformer for interconnection; a power converter; and a controller for controlling the power converter, wherein, during a return to grid connected operation, the power converter is controlled such that the phase of an output voltage of the power converter matches the phase of the system voltage, and the circuit breaker is closed, so as to prevent an overcurrent during a changeover from the self commutated operation to the grid connected operation of the power converter.

Phase synchronization system for connecting a power converter to a power distribution system

A replicated controller and a fault recovery method therefor which can restore a faulty system to a normal state without interrupting operation of an equipment, even in an equipment controller performing processing with short operating periods. In a fault recovery method for a replicated controller, control data is divided into a plurality of blocks on the basis of dependency of the blocks, and a plurality of blocks are transferred in a sequential order of superiority of the dependency from the normally operating system to the faulty system in a period over a plurality of operating periods. BY this, even in an equipment controller performing processing at a short operating period, the system, in which failure is caused, can be restored into normal state without interrupting operation of the equipment.

Replicated controller and fault recovery method thereof

A large capacity (1-2 MkVA) driving system for variable-speed-driving an AC motor by a power converter (inverter, converter) in which GTO (gate turn-off) thyristors are used as switching devices. In this system, high frequency GTO thyristors are connected in series, power converters are multiplexed, the AC motor is used in its plural phases, instantaneous spatial vector PWM (pulse width modulation) control is performed, vector control for the motor is performed, and a circuit for recovering snubber energy for GTO thyristors and a power factor adjusting circuit are provided. Thus, this driving system provides a torque ripple of 1% or less, speed response of 60 rad/sec or more, efficiency of 95% or more and a power factor of 98% or more.

Large capacity variable speed PWM spatial vector type sub-harmonic

A control apparatus for controlling a PWM inverter, the PWM inverter receiving AC power and generating an AC output having a controlled frequency to be supplied to an AC motor, comprises a circuit for generating, on the basis of a given running command, a PWM signal controlling the inverter with a given sampling period, and a circuit for controlling the PWM signal generating circuit, whereby the AC motor generates an electromagnetic tone preselected so as to correspond to desired information when the AC motor is driven by output of the inverter controlled by the PWM signal. The above described desired information may be information representing the running state of the motor or selected music.

Control apparatus for inverter for driving AC motor

A power converter comprising: a three phase bridge circuit, each phase of which is composed of series-connected positive and negative arms, each of which arms includes series-connected GTOs; free-wheel diodes coupled in reverse parallel with every GTO; phase snubber circuits provided for every phase, each of which includes series-connected diodes coupled across the series-connected arms through a first capacitor, a junction of the diodes being coupled to a junction of the series-connected arms through a second capacitor and a junction of the first capacitor and the series-connected diodes being coupled to a negative dc terminal through a resistor; and individual snubber circuits provided in the respective GTOs, each of which includes a series connection of a diode and a third capacitor as well as a resistor connected in parallel with the diode; in which the first capacitor has capacitance much larger than the second capacitor, which in turn has capacitance much larger than the third capacitor.

Electric power converter

Growing community of inventors

Hitachi, Japan

Shigeta Ueda