An insulating fluid monitoring block includes an insulating fluid channel. The insulating fluid channel is connected through a branch channel to a cutout. A sensor element is at least partly disposed in the cutout. The sensor element serves for monitoring an insulating fluid. A mounting method for an insulating fluid monitoring block is also provided.

A method of predicting a lifetime of a gas filling of an electrical switchgear is disclosed, wherein pressure values p.sub.1, p.sub.2 in a system of the electrical switchgear containing the gas filling at a predefined temperature T.sub.p at different points in time t.sub.1, t.sub.2 are measured. Based on the pressure difference p between the pressure values p.sub.1, p.sub.2 the lifetime of the gas filling is calculated. Alternatively, the pressure values p.sub.1, p.sub.2 can be taken at temperatures T.sub.1, T.sub.2 within a predefined temperature range at different points in time t.sub.1, t.sub.2.

A contact signal acquisition circuit for online checking a gas density relay on site is provided, including a first connecting circuit, connecting a contact of a gas density relay to a contact signal control loop, and a second connecting circuit, connecting a contact of the gas density relay to a contact signal sampling interface of an online check device. In a non-checking state, the second connecting circuit is disconnected, and the first connecting circuit is closed; and in a checking state, the first connecting circuit is disconnected, and the second connecting circuit is connected, so as to connect the contact of the gas density relay to the contact signal sampling interface of the online check device, guaranteeing that no contact action signal is uploaded during checking and safe operation of a power grid is not affected.

A gas density relay check device and a check method thereof are provided. In check, a temperature adjusting mechanism and a gas density relay are relatively set. Temperature rise and fall of a temperature compensation element of the gas density relay is adjusted through the temperature adjusting mechanism, then the gas density relay is enabled to have a contact signal action. A gas density value is obtained according to the pressure value and the temperature value in the contact action. A contact signal operating value of the gas density relay is detected to check on the contact signal operating value of the gas density relay. The gas density relay check device of the present disclosure is capable of accurately checking gas density relays, and is particularly applicable to a gas density relay without a three-way valve, and check can be achieved without disassembling the gas density relay.

An optimized method of monitoring a circuit breaker containing a gas with at least one gas characteristic providing a numerical value includes the steps of a) collecting a dataset referring to the at least one gas characteristic inside the circuit breaker, wherein the dataset contains the numerical value of the at least one gas characteristic during a specific condition or specific time of the day, b) calculation of a standard deviation of the at least one gas characteristic of the datasets of at least 3 days of the last 10 days, c) comparing the standard deviation of the gas pressure with a predefined threshold value, and d) triggering a first action in case the standard deviation exceeds the threshold value.

To improve the reliability of gas space monitoring of a gas space (17) of an electrical system (40) filled with a harmful gas, the invention provides a multi-path valve device (44) for connecting a density monitor (20) to a system to be monitored for gas density, comprising a first gas connection (13) for connecting the valve device (44) to the system, a second gas connection (14) for connection to the density monitor (20), a third gas connection (15) for connection of a testing device (19) for testing the function of the density monitor (20), and switching device for selectively connecting the second gas connection (14) to the first gas connection (13) or the third gas connection (15).

A gas monitoring system includes a gas-insulated switchgear including a chamber filled with an insulating gas surrounding a high or medium voltage component, a sensor operatively connected to the chamber and adapted to measure a physical property of the insulating gas in the chamber over time, and a computer unit adapted to perform on the sensor measurements a statistical step detection for determining if a jump has occurred and/or a statistical change detection for determining if a change has occurred, whereby the statistical step and/or change detection includes identifying an expected range based on past sensor measurements and checking if a current sensor measurement is outside of the expected range.

A sensor system for determining physical variables of a switchgear assembly having a sensor connection, which is designed for connection to the switchgear assembly, within which a humidity sensor and/or a pressure sensor and a light sensor for detecting light flashes are arranged. A switchgear assembly is provided that is filled, in particular, with a protective gas, comprising at least one such sensor system.

The application provides an electrical system with online sampling and check function and its check method for high-voltage and medium-voltage electrical equipment, including electrical equipment, gas density relay, gas density sensor, temperature regulation mechanism, online check contact signal sampling unit and intelligent control unit. The temperature rise and fall of the temperature compensation element of the gas density relay is regulated through the temperature regulation mechanism to enable the contact action of the gas density relay of electrical equipment. The contact action is transmitted to the intelligent control unit through the online check contact signal sampling unit. The intelligent control unit detects the alarm and/or blocking contact signal operating value and/or return value according to the density value of the contact action; the check of the gas density relay can be completed without maintenance personnel on site, which greatly improves the reliability of the power grid and the work efficiency, and reduces the O&M cost. At the same time, it also realizes the mutual self-inspection between gas density relay and gas density sensor, and further realizes the maintenance-free.

The application provides an electrical system with online sampling and check function and its check method for high-voltage and medium-voltage electrical equipment, including electrical equipment, gas density relay, gas density sensor, valve, pressure regulating mechanism, online check contact signal sampling unit and intelligent control unit. The pressure is increased or decreased by the pressure regulating mechanism to enable the contact action of the gas density relay of electrical equipment. The contact action is transmitted to the intelligent control unit through the online check contact signal sampling unit. The intelligent control unit detects the alarm and/or blocking contact signal operating value and/or return value according to the density value of the contact action; the check of the gas density relay can be completed without maintenance personnel on site, which greatly improves the reliability of the power grid and the work efficiency, and reduces the O&M cost. At the same time, it also realizes the mutual self-inspection between gas density relay and gas density sensor, and further realizes the maintenance-free.