Hitachi, Ltd.

Hitachi Mitsubishi Hydro Corporation

Other

Fuji Heavy Industries Ltd.

Hitachi Industrial Products, Ltd.

East Japan Railway Company

Hitachi Home and Life Solutions, Inc.

Masaya Ichinose

Motoo Futami

Mitsugu Matsutake

Shinya Oohara

Hiromitsu Sakai

Kazuhiro Imaie

Akira Bando

Akira Kikuchi

Yasuhiro Kiyofuji

Kazumasa Ide

Mamoru Kimura

Kenji Takeda

Hiroshi Arita

Susumu Nakano

Masahiro Komachiya

Masanori Watanabe

Toru Yoshihara

Kenji Kubo

Toshihiko Fukushima

Masatoshi Watanabe

Tomomichi Ito

Yasunori Ono

Kuniyoshi Tsubouchi

Takashi Shiraishi

Yasuhiro Nakatsuka

Shigeo Yoshida

Takeyuki Itabashi

Shuji Katoh

Kiyoshi Sakamoto

Shigeta Ueda

Masahiko Honda

Naomi Sato

Kazuo Suzuki

Shin Kokura

Kouichi Miyazaki

Noriyuki Uchiyama

Yasuhiro Imazu

Tadashi Sodeyama

Shigenori Inoue

Shinichi Kondo

Takashi Aihara

Takayoshi Yamamoto

Shoji Fukuda

Yasuaki Nakayama

Osamu Sakuchi

Tsutomu Hasegawa

Masakazu Ishikawa

Kazumi Fujii

Takashi Matsunobu

Kenta Watanabe

Jun Narushima

Yoshio Eguchi

Kenichi Azegami

Takuji Yanagibashi

Takahiko Kikui

Hikaru Meguro

Takashi Oyake

Junji Tamura

Junichi Sugino

Akira Bandou

Tohru Yoshihara

Kazuya Tsutsumi

Hajime Komiyama

Kojiro Yamashita

Keiichi Yamashita

Rikiya Inoue

Masaki Uchita

Toshihiko Usui

Akira Maekawa

Yuki Ishikura

Ryou Fujita

There is provided an adjustable speed generator motor system with full power converter (FPC system) in which two 3-level converters are connected back-to-back on the DC side, and by providing a mode in which a fly-wheeling diode is forced to conduct a current independently for three phases according to the current polarity and a mode in which the fly-wheeling diode is forced to conduct a current independently for three phases according to magnitude relation of the absolute value of a 3-phase AC current and the current polarity of each phase the FPC system is capable of continuing stable operation.

Adjustable speed generator motor system with full power converter

In a variable speed generator/motor device including a variable frequency power converter, a direct current voltage device including a voltage type self-excited converter, an automatic voltage adjuster, and a converter current adjuster that controls unit converters, a first three-phase branch circuit is provided between the direct current voltage device and an alternating current system; a second three-phase branch circuit is provided between the variable frequency power converter and a three-phase alternating current synchronous machine; a first load switch is provided between the first three-phase branch circuit and the second three-phase branch circuit; a measurement current transformer is provided between the three-phase alternating current synchronous machine and the second three-phase branch circuit; when switching from a converter mode in which the variable frequency power converter drives the three-phase alternating current synchronous machine to generate power to a bypass mode, the first load switch is closed to stop a gate command to the unit converters; and when switching from the bypass mode to the converter mode, a current command value of the converter current adjuster is calculated from a current value of the measurement current transformer, the gate command to the unit converters is started, and the first load switch is opened.

Variable speed generator/motor device

Feeder sections to be a target of interchange are to be expanded in order to improve the effect of power interchange between feeders. A control device for railway power conditioner is connected to a first feeder connected to a load side of a transformer in a first railway substation including a transformer receiving power from a power grid, and a second feeder connected to a load side of a transformer in a second railway substation including a transformer receiving power from a power grid, and decides an amount of power interchanged between the first and second feeders. The control device decides the amount of power interchanged between the first and second feeders, using the received power in the first railway substation and power on the first feeder, and the received power in the second railway substation and power on the second feeder.

Control device for railway power conditioner and control system for railway power conditioner

A switching element of a power converter generates a low voltage, using a current flowing in the power converter, and supplies a power to drive itself. A switching element of a power converter for conversion from direct current into alternate current or from alternate current into direct current includes: a terminal and a terminal which are used in building the switching element itself in the power converter; a capacitor, a high-side controllable switch and a low-side controllable switch enabling outputting the voltage of the capacitor, the voltage being output between the terminal and the terminal, and a self-supply power source for supplying a power to drive the bi-directional chopper switching element itself, using a current flowing in the capacitor.

Switching element, power converter, direct current transmission system, current control device, method of controlling power converter, and method of controlling current in voltage source converter

This invention is intended to provide a wind power generator system or method for controlling a wind power generator system, designed to implement switching-initiated smooth energy changeover without leading to a complex system configuration. The method of controlling a wind power generator system according to an aspect of the invention, wherein the generator system includes a wind turbine that uses wind to generate electric power and a control device that controls the wind turbine, is a control method designed so that when the wind turbine is generating power, the turbine drives the control device by use of the turbine-generated power, irrespective of an electric power system state.

Wind power generator system, and control method for the same

A control apparatus for use with a voltage source converter includes legs, each of which is configured by a plurality of converter modules each having a capacitor. Each of the legs has a first terminal on a positive side and a second terminal on a negative side. The control apparatus is configured to create command pulses for operating the converter modules. The command pulses have a frequency that is a non-integer multiple of a frequency of a system voltage. The non-integer multiple may be, for example, 3.5.

Multilevel voltage source converter and method for balancing capacitors

The excitation overcurrent detection unit for the doubly-fed electric machine is provided with a function to determine an excitation current magnitude relationship among three phases. The firing pulse is held to on-state or off-state to cause the largest-current phase and the second-largest-current phase to charge the DC capacitor by the operation of diodes. The conduction ratio of the third-largest-current phase or minimum current phase is controlled according to the detected current value to protect against a possible short-circuit across the DC capacitor. When the voltage of the DC capacitor exceeds a preset value, the voltage is suppressed by operating active or passive power devices.

Doubly-fed generator and doubly-fed electric machine

A commanded negative-sequence current is added to a commanded current so as to suppress double-frequency pulsation on the DC side. The commanded negative-sequence current is found from three values (i.e., the detected value of positive-sequence voltage vector on the power-supply side, the detected value of negative-sequence voltage vector, and a commanded positive-sequence current). Thus, the pulsations which occur on the DC side of a semiconductor power converter and which have a frequency double the power-supply frequency are suppressed even when the AC power supply is at fault while assuring stability of the current control system, thus permitting stable and continuous operation.

DC/AC power converter with DC side double frequency pulsation suppression caused by AC side faults

The disclosed windfarm control system comprising a windfarm and a central controller; the windfarm including plural wind power generators whose rotational speeds are variable, plural aerographs disposed in the vicinity of the wind power generators to measure the directions and powers of the wind at the sites of the generators, and plural local controllers disposed in the vicinity of the wind power generators to control the output of the wind power generators by controlling the rotational speeds of the generators; wherein the central controller calculats the control level which maintains the output of the windfarm constant for a predetermined time period and instructs the local controllers to control the rpm's of the wind power generators in accordance with the control level.

Controller and control techniques for windfarm

A wind power generating system includes a unit for eliminating harmonics component of specified-order from inputted current detection value of a grid-side converter and a unit for controlling the grid-side converter using the current detection value in which harmonics are eliminated.

Wind power generating system and control method for the same

A wind turbine generator system can regulate the rotational velocity of the wind turbine within an operation range even when the wind velocity suddenly changes and can perform continuous operation of the wind turbine. The wind turbine generator system includes a generator connected to the shaft of the wind turbine and a converter connected to the generator. When the rotational velocity of the wind turbine is within a predetermined range, power outputted from the generator is controlled so as to follow the instruction concerning the generator output given from the wind turbine to the converter. When the rotational velocity of the wind turbine is out of the predetermined range, the power outputted from the generator is controlled without following the instruction concerning generator output given from the wind turbine to the converter.

Wind turbine generator system

In a controller for a windfarm including a plurality of wind turbine generators controllable in rotation frequency and pith of blades of the wind turbine generators, coupled to a grid through a transmission line, an anemometer is provided to each wind turbine generator to transmits wind direction and wind speed data to a central controller which process the wind direction and wind speed data to transmit an output command each wind turbine generator. The central controller predicts, on the basis of the wind speed detected by the upstream wind turbine generator, variation in wind speed at other wind turbine generators to control the output of the windfarm. The output power may be limited or charging energy as rotation energy of blades and discharging the rotation energy as output power in addition to a battery unit for averaging.

Controller and control method for a wind farm including a plurality of wind turbine generators

A wind power generation system includes an excessive current consumption device, an AC input of which is connected between a generator rotor and an excitation converter on a system failure to detect a DC voltage ascent of the excitation converter and operate a shunt circuit on the system failure.

Wind power generation system

In a wind power generation system, an energy consuming unit is connected to a DC part of a generator-side converter. A shunt circuit is connected between the generator-side converter and a rotor of an AC-excited power generator. In the event of system failure, the switching operation of the converter is stopped, the shunt circuit is put into operation, and the energy consuming unit is put into operation so that DC voltage (voltage of the DC part) is maintained within a prescribed range.

Wind power generation system and control method thereof

Growing community of inventors

Hitachiota, Japan

Masaya Ichinose