Hitachi, Ltd.

Masaru Tatemi

Toshiaki Rokunohe

Makoto Hirose

Hisao Inami

Hiroyuki Nakamichi

Hideaki Uchiyama

Masanori Otsuki

Akira Takahama

A diagnostic method of switchgear and a device of switchgear that allow regularly grasping a state with high accuracy with a simple configuration is provided. The diagnostic method of switchgear includes: obtaining signals from an acceleration sensor mounted to a switchgear and a load current flowing through the switchgear; determining a frequency to be focused from a spectrum analysis result of the signals from the acceleration sensor in an advance preparation phase of diagnosis of the switchgear, generating learning data using at least the frequency and the load current as feature values; and regularly diagnosing the state of the switchgear from the feature values obtained during diagnosis and the learning data during the diagnosis of the switchgear.

Diagnostic method of switchgear and device thereof

A symptom of malfunction regarding operating characteristics of a switch should be detected exactly. A switch operating characteristic monitoring device is comprised of a current sensor that measures a close command current of a switch, an auxiliary switch that outputs signals from at least two or more auxiliary contacts with reference to positions of a contactor, a measurement unit that measures signals from the current sensor and the auxiliary switch, a diagnosis unit that judges whether or not a malfunction occurs, and a display unit that displays a malfunction when a malfunction has been determined. A threshold is obtained in advance from multiple results of an opening/closing test performed beforehand. A calculation is made for characteristic times which are obtained from the close command current and signals from the auxiliary switch during actual operation of a circuit breaker. If a deviation is found by comparison with a threshold, a malfunction is determined.

Switch operating characteristic monitoring device, switch equipped with same, and switch operating characteristic monitoring method

A gas leak detection device includes a learning section, which has a correlation between a gas temperature inside gas pressure containers and a surface temperature of the gas pressure containers in a learning period corresponding to a current value flowing in the conductor, to make database, and a diagnosis section, which extracts a gas temperature corresponding to the measured current value and the surface temperature from the learning section in a diagnosis period, corrects a gas pressure value corresponding to an arbitrary surface temperature to a gas pressure value of a reference temperature using the extracted gas temperature, and detects a leak of the insulating gas based on the corrected gas pressure value.

Gas leak detection device and gas leak detection method

Growing community of inventors

Tokyo, Japan

Masaru Tatemi