Hitachi, Ltd.

Hitchi, Ltd.

Hitachi Building Systems Co., Ltd.

Kiyoshi Nakata

Tokunosuke Tanamachi

Kiyoshi Nakamura

Mutsuhiro Terunuma

Masato Suzuki

Yoshio Tsutsui

Shin Kimura

Akira Horie

Eiichi Toyota

Mutsuhiro Mori

Kouji Yasuda

Ryuichi Saito

Tetsuo Kojima

Yoshihiko Koike

Syuuji Saitoo

Shigeki Sekine

Satoru Inarida

Masahiro Nagasu

Atsushi Abe

Satoshi Yamaguchi

Takeshi Tanaka

Toshiaki Okuyama

Wataru Miyake

Seiji Ishida

Shuichi Terakado

Katsumi Ishikawa

Keisuke Horiuchi

Yutaka Sato

Noriyoshi Urushiwara

Motomi Shimada

Takayuki Matsui

Kazutoshi Ogawa

Yasushi Nakamura

Takeo Takagi

Tomomi Kanazawa

Akira Kimura

Takeshi Ando

Takeshi Shinomiya

Masaomi Konishide

Toshihiko Sekizawa

Tetsu Sugiura

Katsuaki Suzuki

Kuniaki Otsuka

Yasuhiko Kono

Syuuji Saitou

Yasuhiko Kouno

Naoki Kunihiro

Youji Takahashi

Hiroyuki Shirata

Taku Yamamoto

Akihiro Hishida

Takashi Ogawa

Kiyoshi Terasawa

Seiji Ishda

Naoki Kurihara

Masaru Katagiri

Emi Onuma

Kentarou Mae

Naoya Hashiguchi

Masataka Ayata

This three-phase AC motor drive device is provided with: a load; an inverter devicefor driving the load; an MCOK_A_connected between the inverter deviceand the load and electrically connecting or disconnecting the inverter deviceto or from the load; a voltage detectorhaving terminals respectively connected to the circuits of at least two phases to detect the voltages between the three phases; and a current detectorfor detecting the currents of the three phases. In the connection from the inverter deviceto the load, the inverter device, the MCOK_A_, the voltage detector, the current detector, and the load are aligned in this order.

Three-phase AC motor drive device, rail vehicle equipped with same, and three-phase AC motor drive method

A power conversion device achieves size reduction and reliability by reducing the number of components of the system. The power conversion device has a semiconductor module of a half-bridge configuration in which two semiconductor elements are arranged in series. The semiconductor module has a cuboidal shape and has, along a longitudinal direction thereof, a positive pole terminal, a negative pole terminal, and terminals for inputting or outputting alternating current or for forming a single phase of the power conversion device. In the vertical direction corresponding to a widthwise direction of the cuboid, a plurality of the semiconductor modules are arranged vertically, forming a plurality of phases of the power conversion device. The semiconductor modules of the plurality of phases are installed in contact with a cooling unit, and one or more capacitors are disposed so as to face the cooling unit across the semiconductor modules of the plurality of phases.

Power conversion device and electric railroad vehicle equipped with power conversion device

Filter capacitor voltage &ldquo;Ecf &rdquo; is detected and then after d-axis voltage correction value &ldquo;dvd&rdquo;, q-axis voltage correction value &ldquo;dvq&rdquo;, q-axis current correction value &ldquo;diq&rdquo;, and frequency correction value &ldquo;d&ohgr; &rdquo; have been computed from the AC components of &ldquo;Ecf &rdquo; and the results have been added to the corresponding d-axis voltage command, q-axis voltage command, q-axis current, and frequency command, the DC current of the power converter is controlled. Thus, the AC components included in the DC current are offset and the AC components are suppressed effectively.

Control apparatus for power converter

The voltage applied to a power converter is detected by a voltage detector, a function generator produces a voltage proportional to this detected voltage, and a high-pass filter detects an AC component superimposed on the voltage. An adder adds a bias voltage to this AC component, and an adder adds the output from the adder and the output from the function generator. The output from the adder is compared with a triangular wave produced from a rectangular wave generator, and a switching element is controlled to make switching operation according to the compared result. When a DC current is decreased by the AC component, a resistance current Ib is increased so that the AC components superimposed on the current and resistance current can be cancelled out.

DC apparatus and vehicle using the same

A railway vehicle operation-control system includes at least one central processing unit being connected to a plurality of devices, which are connected in parallel, via information communication means, the plurality of the devices having at least one operational state-monitoring function which transmits information on operational states of each device to the central processing unit; wherein a total controlled-variable necessary for the system is attained by allocating the total control variable to each device based on operational states determined from results of monitoring performed by the operational state-monitoring function, and a performance margin which is defined as a difference between a permissible power-output value and a current power-output value for each device while monitoring and reflecting the performance margin of each device.

Railway vehicle operation-control system and a railway vehicle using the operation control system

Method for controlling a vehicle provided with an electric power converter

To determine the timing of the electrical brake for completely stopping in electrical braking control, and also to achieve both sure stopping and good riding comfort in an electric vehicle powered by the motor by decreasing the braking force at a prescribed rate of change, the torque of the electric motor is controlled by controlling the power converter which powers the motor using a power converter controller. The deceleration of the motor is computed based on the detected speed of the electric motor which is as an output of the speed detection means, the subsequent speed of the electric motor is estimated based on the detected speed and the deceleration rate of the electric motor at the time the detected rotational speed of the electric motor falls below a prescribed speed, and torque control is carried out using an electric power converter controller, based on the estimated speed.

Control apparatus of electric vehicle

An electric power translating device employs a converter for converting an AC source voltage into a DC voltage, a smoothing capacitor connected at the DC side of the converter, an inverter for inverting the DC from the smoothing capacitor into an AC and for supplying the AC to an AC motor and means for controlling the voltage, frequency or phase in the AC output from the inverter. The device further includes means for regulating at least one of voltage, frequency and phase in the AC output of the inverter based on a ripple frequency component contained in the AC output of the inverter and associated with the rectification by the converter. Whereby, beat phenomenon caused by rectification ripple is suppressed.

Control device for electric power translating device

In order to detect a current with high accuracy in an electric power converting system, an inductor is connected to a main terminal of a switching element in series, and a voltage generated in both ends of the inductor during switching period is integrated using an integrating circuit to detect the current.

Electric power converting system with integrator providing output indicative of current

Apparatus and method for controlling induction motor

An inverter device includes plural modules, each module being formed by a series circuit having a parallel circuit of a switching device and a first diode, and a parallel circuit of a second switching device and a second diode, allowing a reduced size, high reliability, high frequency switching and low noise. Each of the semiconductor modules includes a plurality of switching device chips and at least one diode chip formed on a metal substrate. Electrode plates are provided in locations of the module adjacent to the switching device chips and the diode chips to facilitate connection of the electrodes of the respective chips to one another and to the outside of the module.

Semiconductor module including switching device chips and diode chips

An inverter device includes plural modules, each module being formed by a series circuit having a parallel circuit of a first switching device and a first diode, and a parallel circuit of a second switching device and a second diode, allowing a reduced size, high reliability, high frequency switching and low noise.

Semiconductor module for a power conversion device

In a pulse width modulation control method and system for an electric power converter, in order to suppress the occurrence of lower order harmonics and fractional order harmonics in a direct current component even in a condition where a carrier frequency is several times as small as the frequency of a command value, pulse width modulation pulses for driving semiconductor elements in the electric converter are calculated by comparing a command signal from a command value generating means with a carrier signal having a continuous triangular-wave and a constant period. For this purpose, there is provided a means for separately calculating a time product of a command value of the command signal from the command value generating means and a time product of the pulse width modulation pulses and for calculating a difference value representing a difference between both time products. The pulse width modulation pulse is then calculated using the calculated difference value to compensate the command signal received from the command value generating means.

Pulse width modulation control system for electric power converter

An inverter device includes plural modules, each module being formed by a series circuit having a parallel circuit of a first switching device and a first diode, and a parallel circuit of a second switching device and a second diode, allowing a reduced size, high reliability, high frequency switching and low noise. Each module forms one arm portion of the inverter. Lifetimes of the diodes and the switching devices are set in a manner to equalize losses in the inverter. Preferably, insulated gate bipolar transistors (IGBTs) formed by diffusion are used as the switching devices since the lifetimes of these devices can easily be adjusted to optimize design of the inverter.

Power conversion device and semiconductor module suitable for use in the

Growing community of inventors

Iwase, Japan

Kiyoshi Nakata