The present application provides a gas density relay with sealing performance self-checking function and an implementation method therefor. The gas density relay includes a gas density relay body, a sealing performance detector and an intelligent control unit; the sealing performance detector is communicated with a gas path of the gas density relay body or a sealed cavity in the gas density relay body to obtain gas leakage information of the gas density relay body; the intelligent control unit is connected with the sealing performance detector, receives and/or calculates the data and/or information monitored by the sealing performance detector, and performs diagnosis to obtain the current sealing performance of the gas density relay body; or, the intelligent control unit uploads the received data and/or information to a background, and the background performs diagnosis to obtain the current sealing performance of the gas density relay body. The gas density relay is used to monitor the gas density of gas insulated or arc extinguishing electrical equipment, and the gas leakage performance of the gas density relay can also be monitored on line, which reduces operation and maintenance costs and ensures safe operation of a power grid.

The application provides a gas density relay with online self-check function and its check method, which are used for high voltage and medium-voltage electrical equipment. The gas density relay includes a gas density relay body, a first pressure sensor, a temperature sensor, a force measuring sensor, a driving contact action mechanism and an intelligent control unit. The driving contact action mechanism is configured to directly or indirectly drive the signal action mechanism of the gas density relay body to displacement, so that the gas density relay body will have contact signal action. The intelligent control unit will detect the alarm and/or blocking contact signal action value and/or return value of the gas density relay body according to the density value when the contact acts. Checking the gas density relay can be completed without maintainer coming to the site, which improves the reliability of the power grid, improves the efficiency, reduces the operation and maintenance cost, and can implement the maintenance free of the gas density relay.

An abnormality determination device includes: a first gas density acquisition unit that acquires a first gas density, which is a density of a gas in a gas reservoir unit when the gas reservoir unit has been filled with the gas via a gas filling path; a second gas density acquisition unit that acquires a second gas density, which is a density of the gas in the gas reservoir unit when the gas is supplied from the gas reservoir unit via a gas supply path; and an abnormality determination unit that determines whether or not a first pressure sensor or a second pressure sensor is abnormal, based on the first gas density acquired by the first gas density acquisition unit and the second gas density acquired by the second gas density acquisition unit.

A method for determining a quantity of a gas contained in a tank of an insulated switchgear. The method includes: (i) acquiring a first temperature and a second temperature measured by a gas temperature sensor respectively at a first instant and at a second instant during a calibration phase; (ii) acquiring a first pressure and a second pressure measured by a gas pressure sensor at the first instant and at the second instant; (iii) determining a steady-state model of the tank thermal exchanges from the first and second acquired temperature and from the first and second acquired pressure; (iv) acquiring a gas temperature, a gas pressure and an ambient temperature during a measurement phase and (v) calculating the quantity of the gas contained in the tank from the acquired gas temperature, the acquired gas pressure, the acquired ambient temperature and from the determined steady state model.