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 Δp 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 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.

In a method for determining a fluid density of a fluid in an encapsulated electrical device a sensor unit is used to acquire measurement data. The fluid density is derived from the measurement values. Weather data relating to weather conditions in an environment of the electrical device are collected. Via machine learning, a digital model is generated for the influence of the weather conditions on a measurement deviation of a measurement value from the true fluid density. Using the digital model, a correction value is calculated for measurement values according to the weather data and a measurement value is corrected using the correction value.

The application relates to a method for determining a property of a fluid component of a fluid present in a compartment of an electrical apparatus by means of a measurement device arranged outside the compartment and comprising a chamber for receiving a quantity of the fluid from the compartment. Amongst other steps of the method, an optical path in the chamber is illuminated by a light source and a first intensity of light is measured by a light detector. Then fluid is released from the compartment into the chamber and a second intensity (Ix) of light is measured. Based on these measurements the property of the fluid component is determined.

A gas monitoring system includes a gas-insulated switchgear, wherein the gas-insulated switch gear has at least two separated chambers which are filled with an insulating gas surrounding high or medium voltage components. A first sensor is connected to the first chamber and a second sensor is connected to the second chamber, both sensors adapted to measure a physical property of the insulating gas in their respective chambers over time. A computer unit is adapted to calculate from the two sensor measurements a leakage rate of the insulating gas in one of the two chambers using an adaptive filter, in particular a Wiener filter.

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.

The application relates to a method for determining a property of a fluid component of a fluid present in a compartment of an electrical apparatus by means of a measurement device arranged outside the compartment and comprising a chamber for receiving a quantity of the fluid from the compartment. Amongst other steps of the method, an optical path in the chamber is illuminated by a light source and a first intensity of light is measured by a light detector. Then fluid is released from the compartment into the chamber and a second intensity (Ix) of light is measured. Based on these measurements the property of the fluid component is determined.

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 gas monitoring system includes a gas-insulated switchgear, wherein the gas-insulated switch gear has at least two separated chambers which are filled with an insulating gas surrounding high or medium voltage components. A first sensor is connected to the first chamber and a second sensor is connected to the second chamber, both sensors adapted to measure a physical property of the insulating gas in their respective chambers over time. A computer unit is adapted to calculate from the two sensor measurements a leakage rate of the insulating gas in one of the two chambers using an adaptive filter, in particular a Wiener filter.

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.