Hitachi Industrial Equipment Systems Co., Ltd.

Kaken Pharmaceutical Company, Ltd.

Takuya Sugimoto

Yusaku Onuma

Hiroshi Watanabe

Satoru Kaneko

Kazuaki Tobari

Yoshitaka Iwaji

Shigehisa Aoyagi

Atsuhiko Nakamura

Norio Watanabe

Yusuke Arao

Agnes Hadinata

Yoshiyuki Taguchi

Noboru Momose

Yasuhiko Sato

Katsuya Taguchi

Midori Takaoka

Masato Ohya

Mutsuo Tokashiki

Takuma Oba

Hironori Oohashi

The present invention achieves highly accurate control characteristics by estimating an induced voltage coefficient of a magnet motor without rotary auto-tuning. A first power Pc is calculated on the basis of the output voltage and output current of the magnet motor, and a second power P{circumflex over ( )} is calculated on the basis of the electric circuit constant, current command, output frequency, and induced voltage coefficient of the magnet motor. The induced voltage coefficient is estimated so that the calculated first power follows the second power, and the driving of the magnet motor is controlled in accordance with the induced voltage coefficient.

Power conversion device

The purpose of the present invention is to provide a power conversion device capable of suppressing an increase in current flowing through a motor even if a voltage command exceeds the amplitude of a carrier wave. To achieve the above purpose, a power conversion device, which controls the drive of a three-phase motor by converting a DC voltage into a voltage command-based voltage through the operation of a switching circuit, comprises: a DC voltage detector which detects a DC voltage; a norm generator which generates a voltage command norm from the voltage command; a modulated wave generator which generates a first modulated wave from the detected DC voltage and the voltage command norm; and a control signal generator which generates a control signal for controlling the operation of the switching circuit from the first modulated wave and the carrier wave, wherein the modulated wave generator generates, for one phase at the timing of the maximum or minimum value of the voltage command, a first modulated wave having a magnitude of ½ of the detected DC voltage, and generates, for the remaining two phases, a first modulated wave having a magnitude based on the detected DC voltage and voltage command norm.

Power conversion device and control method thereof

An object of the present invention is to provide a power conversion device capable of suppressing an increase in a current flowing through a motor even if a voltage command exceeds the amplitude of a carrier wave. In order to achieve the above object, the power conversion device controls the driving of a motor by converting a DC voltage into a voltage based on a voltage command by an operation of a switching circuit and includes: a modulated wave generator that generates a first modulated wave from the voltage command; and a control signal generator that generates a control signal for controlling the operation of the switching circuit from the first modulated wave and a carrier wave. The modulated wave generator generates a square wave based on a voltage command norm as the first modulated wave.

Power conversion device and method for controlling same

This power conversion device comprises: a power converter including a switching element; and a control unit which controls the power converter. The control unit calculates a torque electric current detection value and an excitation electric current detection value from an electric current flowing to an external device, and when an absolute value of the torque electric current detection value is greater than or equal to the excitation electric current detection value, performs control such that the excitation electric current detection value follows the torque electric current detection value.

A power conversion device includes a harmonic voltage generation unit that superimposes dc-axis and qc-axis harmonic voltages on dc-axis and qc-axis voltage commands in accordance with a switching signal; and an inductance estimation unit that estimates dc-axis inductance and qc-axis inductance on a basis of dc-axis and qc-axis harmonic currents, amplitude values of the harmonic voltages, and the switching signal.

A power conversion apparatus controls a load apparatus by position sensorless vector control. The power conversion apparatus includes: a current detection unit configured to detect a current passing through the load apparatus; a current detection arithmetic unit configured to calculate a harmonic current component on a dc-axis as a control axis and a harmonic current component on a qc-axis, based on the detected current; a saliency ratio estimation unit configured to output a saliency ratio estimated value based on the harmonic current component on the dc-axis and the harmonic current component on the qc-axis; and a saliency ratio control unit configured to output a current component that increases or decreases a current command value on a d-axis of a rotor coordinate system, based on a deviation between the saliency ratio estimated value and a predetermined saliency ratio.

Power conversion apparatus

According to the present invention, in position sensorless control for switching between a 120-degree energization scheme for a low-speed region and a 180-degree energization scheme for a mid-to-high-speed region, stable and highly accurate speed control characteristics are provided by suppressing speed deviation &#x394;&#x3c9;r in the low-speed region, and by preventing current jump-up caused by a discontinuous rotational speed occurring during switching to the mid-to-high-speed region. In the case of driving in the 120-degree energization scheme, a voltage command value is corrected such that an estimated speed value or a detected speed value follows a speed command.

Synchronous motor control apparatus

A syringe device includes an administration holder, and a cylinder portion which allows insertion of the administration holder. The cylinder portion includes a coupling holder, a slit holder coupled to the coupling holder, and a double-ended needle assembly disposed slidably in an interior of the coupling holder. A cartridge for a freeze-dry product is mounted, in the administration holder, and a cartridge for solvent is mounted in the coupling holder. When the administration holder is pushed, the double-ended needle assembly slides. When one of the needle points pricks the cartridge for freeze-dry product, the other needle point of the double-ended needle assembly pricks the cartridge for the solvent, and then the needle points unseal the cartridges by a further sliding movement of the double-ended needle assembly.

Growing community of inventors

Tokyo, Japan

Takuya Sugimoto