Method and system for controlling the supply of nitrogen to electrical power handling equipment
AssigneeWaukesha Electrical Systems, Inc.
InventorsThomas M. Golner, Shirish P. Mehta
Life of this patent
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Abstract
A system that controls nitrogen pressure in the ullage of a power transformer that has its windings submerged in oil. The pressure is controlled in a narrow range of approximately 0.5 psi to approximately 2.0 psi. A nitrogen generator supplies the nitrogen to a reservoir from which it is distributed to the ullage as well as to accessories such as a load tap changer or a control box. A temperature regulator is provided for substation installations that are located in climates with wide ambient temperature variations to control the pressure of the generated nitrogen in an acceptable range.
Claims13
A method of controlling a positive nitrogen atmosphere in a ullage above a volume of oil in an electrical power handling equipment, said method comprising:
- (a) supplying nitrogen to said ullage;
- and
- (b) controlling the pressure of said nitrogen in said ullage in a range of about 0.5 psi to about 2.0 psi, whereby nitrogen bubbling in said oil due to changes in pressure is substantially minimized, wherein step (a) further comprises:
- (a1) supplying said nitrogen at a relatively low pressure during a first interval;
- and
- (a2) supplying said nitrogen at a relatively high pressure during a second interval.
A system for controlling a positive nitrogen atmosphere in ullage above a volume of oil in an electrical power handling equipment, said system comprising:
- a supply of nitrogen connected to supply said nitrogen along a delivery path to said ullage;
- and
- a pressure control connected with said delivery path to control the pressure of said nitrogen in said ullage in a range of about 0.5 psi to about 2.0 psi, whereby nitrogen bubbling in said oil due to changes in pressure is substantially minimized,
- wherein said supply of nitrogen includes a nitrogen generator that supplies said nitrogen at a relatively low pressure during a first interval and a relatively highly pressurized source that supplies said nitrogen at a relatively high pressure during a second interval.
Dependencies are inferred from the claim text.