Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Hino Jidosha Kogyo Kabushiki Kaisha

Hiroshi Uchino

Hajime Yamamoto

Shigeru Tanaka

Ryoichi Kurosawa

Takeo Shimamura

Kihei Nakajima

Mami Mizutani

Yukitaka Monden

Tetsuo Koike

Hiroyuki Nishikawa

Takayuki Suzuki

Takeo Kanai

Atsuomi Obata

Kouzou Kawata

Masaaki Shigeta

Masashi Shigemori

Kohji Sasaki

Sadayoshi Iketani

Takashi Fujita

Takeshi Kitahata

Kentaro Suzuki

Akira Kawaguchi

Ryuichi Morikawa

Tadashi Nishikawa

Kiyoshi Kusunoki

Takahisa Kageyama

Kenichi Otsuka

Shoichi Irokawa

Tadahiro Sakamoto

The power conversion device of the present invention comprises a power diode rectifier (REC) whose AC terminal is connected through an AC reactor (Ls) with an AC power source; voltage-type self-commutated power converters (CNV) whose AC terminals are connected with the AC terminal of this power diode rectifier through a recovery current suppression reactor (La); and a DC smoothing capacitor (Cd) connected between a DC common terminal of this voltage type self-commutated power converter and the power diode rectifier, with a load device connected in parallel therewith.

Power conversion device

A synchronous motor controller comprises speed control means for calculating an active current reference value on a basis of a deviation of a speed sensed value from a speed reference value of the synchronous motor, three-phase PQ conversion means for calculating an active current value and reactive current value on a basis of an armature current of the synchronous motor and a voltage phase reference value active current control means for calculating a voltage phase compensating value on a basis of a deviation of the active current value from the active current reference value, voltage phase computing means for calculating the voltage phase reference value and polar-coordinate three-phase conversion means for calculating a three-phase voltage reference value on a basis of the voltage phase reference value and a voltage amplitude reference value.

Apparatus for controlling synchronous motor

A series compensator, connected in series to an AC transmission line, for compensating for an electric amount, such as a voltage, current, phase or impedance, of the AC transmission line, comprises a first capacitor and a second capacitor connected in series to each other and connected to the AC transmission line, and a compensation current generator connected in parallel to the first capacitor. This structure eliminates the need for a bypass transmission line to simplify the main transmission line structure, has an enhanced current controllability, reduces harmonics to be generated and realizes an economical way of ensuring a large compensation amount.

Series compensator

A control apparatus for a power converter having a plurality of semiconductor switching devices that converts DC power into AC power and outputs three levels of voltages, including a command voltage generator configured to output a command voltage vector that represents a voltage to be output from the power converter, an integrator configured to calculate a difference integral vector by integrating a difference between the command voltage vector and an output voltage vector that represents a voltage command for the power converter, a difference vector calculator configured to calculate difference vectors by subtracting the command voltage vector from each of the possible output voltage vectors, a vector selector configured to select one of the possible output voltage vectors which corresponds to one of the difference vectors making the largest angle with the difference integral vector as the output voltage vector only if the difference integral vector exceeds a predetermined value, and a gate signal generator configured to determine one of switching states that includes a plurality of ON-OFF pattern signals for turning on and off the semiconductor switching devices on the basis of the output voltage vector.

Control apparatus for power converter

A series compensation generator SCG is installed in a transmission line that links various substations SS and the transmission capability of the system as a whole can be increased by regulating the equivalent reactance of the transmission line. Series compensation generator SCG generates a voltage of which the phase angle is shifted substantially 90&deg; in relation to the current flowing in the transmission line, and it also generates a voltage that compensates the voltage drop due to the equivalent reactance. Also, when an electrical fluctuation phenomenon (power oscillation) occurs in the transmission line, it is possible speedily to suppress the power oscillation by detecting the power fluctuation of the transmission line and controlling the compensating voltage of series compensation generator SCG so that it suppresses that power fluctuation.

AC transmission system with reactance compensation

A power converting system has power converters for converting a direct current into an alternating current, a DC power source arranged on the DC side of the power converters, and voltage dividing transformers having windings whose first ends are connected to the power converters phase by phase and whose second ends are joined together and connected to a load phase by phase. Also provided is a controller for controlling the power converting system.

Power converting system multiplexed with voltage dividing transformers, the voltage transformers, and controller for the system

A power converter includes first and second power conversion units that are connected to each other by a d.c. reactor. The first power conversion unit is a converter in which arms consisting of thyristors are connected in a bridge configuration. The second power conversion unit is an inverter in which arms each of a series combination of a thyristor and a self-excited switch unit having a GTO for producing a commutation voltage for the thyristor are connected in a bridge configuration.

Power converter having first and second power conversion units with

A power conversion system including a DC power source, a plurality of unit converters connected in parallel, each composed of a bridge connected switching devices, a plurality of DC reactors and a control circuit. The control circuit includes a conduction arm number calculating circuit for determining conduction arm numbers of the unit converters of each phase, each being determined based on a ratio of the current instruction value of respective phase and a mean value of the DC currents. The control circuit further includes a current balance control circuit for generating a plurality of conduction instructions for the switching devices at a time of change of one of the conduction arm numbers based on a first order of magnitude of the AC voltages, a second order of magnitude of the DC currents and the conduction arm numbers of each phase at that point. The conduction instructions are applied to the unit converters for switching ON or OFF the switching devices, thereby balance control of the DC currents of the unit converters is exercised.

Plural parallel bridge inverter power conversion system with balanced DC

A control device for a power conversion system with a plurality of power converters, each of which is provided with a DC power source, a DC reactor and a unit converter composed of self-turn-off switching devices with DC terminals connected to the DC power source through the DC reactor, in which AC terminals of the plurality of unit converters are connected in common and is connected to an AC load. The control device includes a first unit for generating an instruction value vector for an AC output current of the power conversion system, a second unit for generating a set of actual value vectors showing all of the AC output currents that can be generated by the power conversion system, a third unit for selecting a closest actual value vector that is closest to the instruction value vector out of the set of the actual value vectors, and a fourth unit for controlling the self-turn-off switching devices in the unit converters in response to the closest actual value vector. The AC output current of the power conversion system is thereby controlled so as to track the instruction value vector.

Power conversion system and control device therefor

A power generation system is constituted by an induction generator and a converter. An output current waveform of the induction generator is determined by the magnetic flux, speed, winding impedance, DC output voltage, and load of the induction generator. In particular, the output current waveform is changed in accordance with a change in speed (i.e., change in slip). Switching elements in the converter are ON/OFF-controlled in accordance with changes in current waveform, thereby controlling power generation of the induction generator.

Power generation system having induction generator and controlled bridge

A power converting apparatus controls switching of self turn-off type semiconductor devices so as to perform power conversion. The apparatus comprises a plurality of switch units each having first and second self turn-off type semiconductor devices, first and second diodes, and a capacitor. The cathode of the first self turn-off type semiconductor device is connected to the anode of the first diode, and the cathode of the second diode is connected to the anode of the second self turn-off type semiconductor device. The capacitor is connected between a common junction between the cathode of the first self turn-off type semiconductor device and the anode of the first diode and a common junction between the cathode of the second diode and the anode of the second self turn-off type semiconductor device.

GTO rectifier and inverter

This invention relates to an electric braking and auxiliary engine mechanism for a motor vehicle including a rotary machine coupled with the crank shaft of the internal combustion engine which drives the axle of the vehicle. This mechanism is characterized in that squirrel-cage polyphase induction machine is used as the rotary machine which is fixedly connected to the crank shaft, and the squirrel-cage polyphase induction mechanism is fed with a revolving magnetic field which is variable either positive or negative direction by an invertor, so that the squirrel-cage polyphase induction machine may be utilized either as a power generator or a motor.

Electric braking and auxiliary engine mechanism for a motor vehicle

An induction system of the invention is adapted to apply coordinate transformation to the excitation current reference vector corresponding to the primary interlinkage magnetic flux vector reference value and the primary current vector so that they exist in the same coordinate system, thereafter to control the secondary current vector so that the primary interlinkage magnetic flux vector is in correspondence with the primary interlinkage magnetic flux vector, thereby allowing the primary side of the wound-rotor induction machine to function apparently as a voltage source.

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Tokyo, Japan

Hiroshi Uchino