Hitachi Industrial Equipment Systems Co., Ltd.

Yusuke Arao

Hiroshi Watanabe

Makoto Tanaka

Hiroyuki Tomita

Satoshi Ibori

Masahiro Hiraga

Masayuki Hirota

Yusaku Onuma

Atsuhiko Nakamura

Takuya Sugimoto

Kazushige Hotta

Yoshihiro Uchino

Keisuke Tanabe

Hidenori Sugino

Takaaki Hayashi

Masataka Sasaki

Tadashi Yamazaki

Shingo Ejima

The purpose of the present invention is to provide a speed detection method for maintaining a fine time axis resolution and a power conversion device that uses the method. This power conversion device comprises an inverter for converting DC voltage into AC voltage and supplying the same to a motor, a motor speed calculation unit for calculating the speed of the motor from output pulses obtained from an encoder connected to the motor, and a control unit for receiving the motor speed from the motor speed calculation unit and controlling the inverter. In the power conversion device, the motor speed calculation unit measures the duty cycle of the output pulses, calculates the speed using the half cycles of the output pulses if the duty cycle is within a prescribed range from 50%, and calculates the speed using the full cycles of the output pulses if the duty ratio is outside of the prescribed range from 50%.

Speed calculation device and power conversion device

A power conversion device includes an AC conversion unit; a detector that detects an output current, a DC voltage, and a temperature; an I/O unit; and a control unit. The control unit includes a motor control unit that controls the AC conversion unit; an operation instruction/parameter setting unit that converts an operation instruction and a parameter; an information management unit; an I/O control unit; and a detection unit that acquires data of the detector. The operation instruction/parameter setting unit outputs the set parameter and characteristic data to the information management unit, which acquires parameter information associated with the operation instruction and parameter information for an operation instruction change quantity required for adjustment from an information server. The operation instruction/parameter setting unit converts the operation instruction into a parameter using the data acquired by the detection unit and the parameter information and sets the parameter in the motor control unit.

Power conversion device, motor control system, and parameter setting method therefor

A power conversion device includes a function of improving safety of a system by making a dynamical setting for a safety function operation at a time of detecting an abnormality in a system operation or a diagnosis error in accordance with a condition of the system at a time of the abnormality. A power conversion system includes a power conversion device main body configured to drive a motor and a safety function unit configured to execute a safety function. The safety function unit outputs a safety function operation instruction signal when receiving a safety request signal, and the power conversion device main body controls the motor by the safety function operation instruction signal. The safety function unit monitors a state of the motor, and, in a case where the state of the motor exceeds a predetermined range, executes a threshold-value-excess post-process by a safety function operation selected in advance.

Power conversion system and power conversion method

This voltage imbalance assessment method is for a power conversion device comprising a forward converter for rectifying the voltage of a three-phase AC power supply, a smoothing capacitor for smoothing the rectified voltage, a detection unit for detecting the smoothed voltage, and a control unit. The control unit: uses the detected voltage to generate data indicating frequency components; compares, in the data indicating frequency components, the magnitude of the component that is four times the power supply frequency with the magnitude of the component that is six times the power supply frequency; and assesses the voltage imbalance of the three-phase AC power supply on the basis of the comparison.

Voltage imbalance assessment method and power conversion device

Disclosed is a power conversion device having an AC conversion unit and a control unit that controls the AC conversion unit. The power conversion device also has: a temperature detection unit that outputs temperature data of the power conversion device; a current detection unit that outputs current data of an output of the AC conversion unit; a storage unit that stores specification data indicating a relationship between a rated current and a temperature specification and temperature data output by the detection unit; an overload protection unit that outputs a shutdown command to the control unit on the basis of the rated current and the current data output by the current detection unit; and a rating determination unit that acquires specification data and temperature data from the storage unit, determines a rated current corresponding to the acquired temperature data on the basis of the acquired specification data, and outputs the determined rated current to the overload protection unit.

Power conversion device

Provided is a power conversion device with which it is possible to acquire a sign of a system stop before the system stops, and to minimize the nonworking time of the system. A power conversion device for converting DC voltage or AC voltage into AC voltage, the power conversion device being characterized by having an abnormality detection unit for detecting abnormalities in the power conversion device, a restart unit for stopping the power conversion device and automatically performing a restart when the abnormality detection unit has detected an abnormality, a restart recording unit for recording restart information of when the restart unit has restarted, and a sign diagnostic unit for inputting the restart information recorded by the restart recording unit and performing a sign diagnosis of the abnormality in the power conversion device on the basis of the restart information, the sign diagnostic unit performing the sign diagnosis on the basis of the number of restarts and outputting a sign diagnostic result.

Power conversion device and power conversion device system

An electric power converting apparatus includes a switching circuit, a PWM controller, conducting PWM all phase shut-off and zero-vector outputting, a unit configured to detect or estimate current flowing through a motor, a unit configured to conduct a DC braking, and a current comparator configured to compare between a DC braking time maximum current setup value, and a current value obtained by the unit configured to detect or estimate current. The PWM all phase shut-off and zero-vector outputting are conducted, repetitively, by the PWM controller, if the current comparator determines that a current value, which is obtained by the unit configured to detect or estimate current, exceeds the DC braking time maximum current setup value, when conducting the DC braking to obtain a braking power by running current through the motor.

Power converter device

A power converter device for achieving a stable braking operation, preventing excessive current to flow therein, when conducting DC braking on a permanent synchronous motor, comprises: a switching circuit for converting DC to AC; a PWM controller means, for controlling ON or OFF of said switching circuit; a means for detecting or estimating current flowing through a permanent magnet synchronous motor; and a means for executing DC braking of said permanent magnet synchronous motor, wherein there are provided a DC braking maximum current setup value, which is determined from an outside or is determined in advance within an inside, and a PWM all-phases cutoff function and a zero vector output function within said PWM controller means, within said PWM controller means, whereby the PWM all-phases cutoff and the zero vector output are repeated within said PWM controller means, if a current value, which is obtained by said means for detecting or estimating the current, exceeds said DC braking maximum current setup value, when running DC current to the permanent magnet synchronous motor, so as to execute DC braking for obtaining a braking power.

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Tokyo, Japan

Yusuke Arao