Method and a system for determining the density of an insulating gas in an electrical apparatus

• Main Authors: THURIES; EDMOND, DUPRAZ; JEAN-PIERRE
• Format: Patent
• Language: English
• Published: 02.12.1997
• Edition: 6
• Subjects: BASIC ELECTRIC ELEMENTS; BOARDS, SUBSTATIONS, OR SWITCHING ARRANGEMENTS FOR THE SUPPLYOR DISTRIBUTION OF ELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRIC SWITCHES; ELECTRICITY; EMERGENCY PROTECTIVE DEVICES; GENERATION; RELAYS; SELECTORS

A method and a system for determining the density of an insulating gas in electrical apparatus in the vicinity of parts carrying electrical current, the method comprising the following steps: a) a reference temperature is measured outside the apparatus and in the vicinity thereof; b) the current passing through the apparatus is measured, and the temperature rise of the gas above the reference temperature is determined on the basis of gas temperature rise values as a function of current values and of various reference temperatures, said temperature rise values having been previously determined by testing or by a mathematical model; c) the gas temperature is computed by adding the reference temperature and the temperature rise; d) the gas pressure inside the apparatus is measured; and e) the density rho of the gas is computed on the basis of equations of state of the gas rho =F(T,P) which equations are tabulated data.