Mitsubishi Electric Corporation

Nagaoka University of Technology

National University Corporation Magaoka University of Technology

Sota Sano

Akira Satake

Yuki Yokokura

Tenjiro Hiwatari

Shinsaku Kusube

Satoru Terashima

Makoto Kanemaru

Kiyoshi Ohishi

Takuya Ohkubo

Yuto Kobayashi

A power conversion device comprises: power conversion circuitry for converting DC power into AC power and supplying it into a load according to a switching state quantity defined by combinations among switching parameters of switching devices; a voltage output calculation device for calculating a voltage output value on the power conversion circuitry, based on the switching state quantity; an integration value calculation device for acquiring a voltage reference integration value and a voltage output integration value by integrating a voltage reference value and the calculated voltage output value; a switching update-determination unit for outputting an update signal of the switching state quantity, based on the voltage reference integration value, its allowance value, and the voltage output integration value; and a switching determination table for determining a switching state quantity of the switching devices, based on the voltage reference integration value, the voltage output integration value and the update signal.

Power conversion device

An abnormality diagnosis device includes: a data acquirer to acquire a current waveform and a driving frequency of an electric motor; a storage which stores a combination of a current value of the current waveform and the driving frequency at an identical time by the data acquirer; a data determiner to determine whether or not a current value of the current waveform and the driving frequency as a diagnosis target at an identical time by the data acquisition match the combination stored in the storage; an analyzer to perform frequency analysis for the current waveform determined to be matched by the data determiner, to extract sideband waves, and calculate a spectrum intensity of the sideband waves; and an abnormality diagnosis processor to make a diagnosis that abnormality has occurred, when the spectrum intensity of the sideband waves is equal to or greater than a threshold.

Abnormality diagnosis device, abnormality diagnosis method, and abnormality diagnosis system

This power conversion device includes: a current detection unit for detecting current flowing through a rotary electric machine; a switching pattern determination unit for determining a switching pattern on the basis of the detected current, a current prediction value, a current command value, and a current harmonic command value; and a power conversion unit for outputting AC power to the rotary electric machine in accordance with the switching pattern, wherein the switching pattern determination unit determines the switching pattern so that the current value follows the current command value and the current harmonic becomes equal to or smaller than a limit value.

The present invention includes a control amount calculation unit which calculates two or more control amounts each indicating a driving condition of a rotary electric machine on the basis of output current from and a switching state in a power converter; a limitation range-provided command value generation unit which generates limitation range-provided command values relative to command values for the control amounts; and a switching state determination unit which determines a switching state such that each control amount falls within the limitation range of the corresponding limitation range-provided command value. For at least one of the limitation range-provided command values, the limitation range thereof is temporally changed on the basis of the driving condition of the rotary electric machine.

Growing community of inventors

Tokyo, Japan

Sota Sano