Method and apparatus for monitoring SF6 gas and electric utility apparatus
AssigneeAvistar, Inc.
InventorsGeorge W. Rhodes, Albert Migliori, Tristan Fin, Steven Frank Willard
Life of this patent
Estimating the term…
Abstract
A method for detecting loss of SF6 gas from electrical utility apparatus determines a molar ratio of gas in a container at an initial time and of gas in the container at a subsequent time. Measurement of temperature is determined by averaging ambient temperature and temperature of the surface of the container. The initial values of pressure and temperature define the initial value of n as follows: no=Pgas o/Tgas o The value at a subsequent time is nn=Pgas n/Tgas n The molar ratio can be defined as nn/no or as no/nn.
Claims18
A method for detecting loss of SF6, also known as sulfur hexafluoride, gas from electric utility apparatus comprising the steps of:
- taking measurements at a beginning time and a later time;
- wherein taking measurements comprise the steps of:
- detecting pressure of a gas containing SF6, also know as sulfur hexafluoride, in a container which encloses an electric utility apparatus;
- detecting ambient temperature where the electric utility apparatus is located;
- detecting temperature of an outer surface of the container, and
- computing an average of the ambient temperature and the temperature of an outer surface of the container;
- computing a molar ratio using pressure and the computed average temperature measurements taken at the beginning time and the later time;
- and
- wherein SF6, also known as sulfur hexafluoride, gas loss from the electric utility apparatus is detected by comparing molar ratio between measurements taken at the beginning time and the later time, and
- conveying SF6, also known as sulfur hexafluoride, loss to a operator.
A method for detecting loss of SF6, also known as sulfur hexafluoride, gas from electric utility apparatus comprising the steps of:
- taking measurements at a beginning time and a later time;
- wherein taking measurements comprise the steps of:
- detecting pressure of a gas containing SF6, also known as sulfur hexafluoride, in a container which encloses an electric utility apparatus;
- detecting ambient temperature where the electric utility apparatus is located;
- detecting temperature of an outer surface of the container, and
- computing an average of the ambient temperature and the temperature of an outer surface of the container;
- computing a molar ratio using pressure and the computed average temperature measurements taken at the beginning time and the later time;
- and
- wherein SF6, also known as sulfur hexafluoride, gas loss from the electric utility apparatus is detected by comparing molar ratio between measurements taken at the beginning time and the later time, and
- where the molar ratio is computed as follows:
- molar ratio=nn/no
- or
- molar ratio=no/nn
- where nn is a measurement taken at a subsequent time and no is a measurement taken at the beginning time and further comprising the steps of taking a plurality of measurements at different times after the beginning time and establishing a ratio trend line based upon at least two of the plurality of measurements.
A method for detecting loss of SF6, also known as sulfur hexafluoride, gas from electric utility apparatus comprising the steps of:
- taking measurements at a beginning time and a later time;
- wherein taking measurements comprise the steps of:
- detecting pressure of a gas containing SF6, also known as sulfur hexafluoride, in a container which encloses an electric utility apparatus;
- detecting ambient temperature where the electric utility apparatus is located;
- detecting temperature of an outer surface of the container, and
- computing an average of the ambient temperature and the temperature of an outer surface of the container;
- computing a molar ratio using pressure and the computed average temperature measurements taken at the beginning time and the later time;
- and
- wherein SF6, also known as sulfur hexafluoride, gas loss from the electric utility apparatus is detected by comparing molar ratio between measurements taken at the beginning time and the later time, and further comprising the steps of taking a plurality of measurements at different times after the beginning time and establishing a ratio trend line based upon at least two of the plurality of measurements.
A method for detecting loss of SF6, also known as sulfur hexafluoride, gas from electric utility apparatus comprising the steps of:
- taking measurements at a beginning time and a later time;
- wherein taking measurements comprise the steps of:
- detecting pressure of a gas containing SF6, also known as sulfur hexafluoride, in a container which encloses an electric utility apparatus;
- detecting temperature of an outer surface of the container, and
- wherein the molar ratio is computed using measurements taken at the beginning time and the later time;
- wherein loss is determined by comparing a molar ratio at the beginning time and the later time and
- comprising the steps of taking a plurality of measurements at different times after the beginning time and establishing a ratio trend line based upon at least two measurements taken after at a plurality of times after a first measurement.
An apparatus for detecting loss of SF6, also known as sulfur hexafluoride, gas from electric utility apparatus comprising:
- a pressure detector for detecting pressure of a gas containing SF6, also known as sulfur hexafluoride, in a container which encloses an electric utility apparatus;
- a temperature detector for detecting ambient temperature where the electric utility apparatus is located;
- a temperature detector for detecting temperature of an outer surface of the container, and
- a computer which computes average temperature measurements of the ambient temperature and the temperature of an outer surface of the container, a molar ratio using pressure and the computed average temperature measurements, taken at a beginning time and a later time;
- and
- wherein loss is determined by comparing molar ratio between measurements taken at the beginning time and the later time.
Dependencies are inferred from the claim text.