Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Shinsuke Miki

Misa Nozuki

Kazuo Hayashi

Shin Sekiya

Shoji Yoshioka

Makiko Kise

Hidetaka Katougi

Yoshinori Shirafuji

Noboru Masuda

Makoto Tsukiji

Hideto Nakao

Takeshi Izawa

Wataru Nagaya

Keisaku Ishihara

Tadao Otani

Hiroshige Fujita

An abnormality diagnosis method for diagnosing an abnormality in operational state of a diagnosis subject includes creating a unit space from normal operation data of the diagnosis subject, the unit space serving as a reference for determining the operational state of the diagnosis subject, acquiring data having state quantities of a plurality of evaluation items from the diagnosis subject, calculating a Mahalanobis distance of the data acquired, using the unit space created, and determining an abnormality in the operational state of the diagnosis subject based on the Mahalanobis distance calculated. The creating a unit space includes creating a plurality of unit spaces having mutually different data lengths The calculating a Mahalanobis distance includes calculating a plurality of Mahalanobis distances using the plurality of unit spaces created. The determining an abnormality includes determining an abnormality based on the plurality of Mahalanobis distances calculated.

Abnormality diagnosis method, abnormality diagnosis device and non-transitory computer readable storage medium

A device for assessing remaining life of a rotating electrical machine includes: a data acquisition unit configured to acquire actual running performance data and electrical data about the rotating electrical machine to be assessed; an index value calculation unit configured to calculate a first index value to a third index value based on the acquired data, and to calculate, as a fourth index value, an estimation value of a residual withstand voltage value of the rotating electrical machine by performing analysis that uses an MT method on each piece of the electrical data; and an insulation deterioration estimation unit configured to assess the remaining life of the rotating electrical machine by estimating the remaining life of the rotating electrical machine with use of four index values from the first index value to the fourth index value.

Method for assessing remaining life of rotating electrical machine and device for assessing remaining life of rotating electrical machine

An abnormality diagnosis method for diagnosing an abnormality in equipment includes acquiring multivariate time-series data for a plurality of measurement items from the equipment, diagnosing an abnormality in operational state of the equipment based on the multivariate time-series data, and diagnosing a cause of the abnormality. The diagnosing a cause of the abnormality includes extracting a feature of a first section before the occurrence of the abnormality from the multivariate time-series data of the first section, extracting a feature of a second section after the occurrence of the abnormality from the multivariate time-series data of the second section, obtaining an amount of change in feature from a difference between the feature of the first section and the feature of the second section, and diagnosing a measurement item that is the cause of the abnormality based on the amounts of change in features of the plurality of measurement items.

A life prediction apparatus for an electrical storage device, which has a life predictor, includes: an operation controller for life prediction that controls operation of the electrical storage device; a data collector that collects measurement data with respect to a plurality of operation conditions and calculates and successively accumulates evaluation characteristics; a data analyzer that creates a regression formula representing a relationship between the evaluation characteristic and an operation time by curve fitting, with an appropriate approximation function, the accumulated evaluation characteristic data; and a life prediction formula creator that creates a life prediction formula for calculating a predicted value of the evaluation characteristic under random operation conditions on the basis of the regression formula.

Life prediction apparatus for electrical storage device and life prediction method for electrical storage device

A discharge voltage detecting unit of an electric discharge machine detects a discharge voltage and determines an average discharge voltage in a specified period of time. An optimum machining condition computing unit determines a discharge current that makes an average discharge voltage detected by a discharge voltage detecting unit equal to an average discharge voltage when a new machining liquid is used. The optimum machining condition computing unit determines an optimal discharging time, an optimal non-operating time, and an optimal servo reference voltage from relational equations depending on the determined discharge current. A machining condition data base storing unit stores the discharge current, the discharging time, the non-operating time, and the servo reference voltage. A servo control unit establishes the optimum machining conditions at the time of machining.

Electric discharge machine and method for optimizing machining conditions of the electric discharge machine

A refrigerant-circulating system which comprises a refrigeration cycle comprising a refrigerant compressor, a condenser, an expansion mechanism and an evaporator to form a refrigerant circuit and employing a refrigerant which contains no chlorine, wherein an aromatic polyether oil having as a base oil structure a benzene ring having an ether bond is employed as a refrigerator oil.

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Tokyo, Japan

Shinsuke Miki