Patent Issued for Wind turbine and method of maintaining a wind turbine (USPTO 11319936)

2022 MAY 19 (NewsRx) -- By a News Reporter-Staff News Editor at Electronics Business Daily -- From Alexandria, Virginia, NewsRx journalists report that a patent by the inventor Hillebrandt, Jesper (Aarhus N., DK), filed on November 6, 2019, was published online on May 3, 2022.

The patent’s assignee for patent number 11319936 is Vestas Wind Systems A/S (Aarhus N, Denmark).

News editors obtained the following quote from the background information supplied by the inventors: “Power electrical devices, such as power transformers, chokes, converters et cetera, develop heat during operation. In order to remove heat and provide insulation these devices may be immersed into a liquid, such as oil. The temperature of the liquid may vary causing expansion and contraction of its volume. To allow for such changes in volume an expansion vessel is required. The change in liquid volume requires an equal change of air volume in the expansion vessel. Thus, to maintain the same pressure in the system, there will be an exchange of air with the ambient environment. This may introduce humidity in the system when air of higher humidity is drawn into the expansion vessel. In order to avoid the ingress of moisture into the system a dehydrating breather is attached to the air exchange inlet of the expansion tank.

“A dehydration breather may comprise a moisture absorbing agent that removes humidity from the air passing through the breather. Moisture absorbing agents may be divided into two groups. Those having automatic regeneration of the moisture absorbing agent and those requiring exchange when saturation of the moisture absorbing agent is approaching.

“In installations with high voltage equipment special procedures and training are required for personnel working near such equipment. Moreover, de-energizing the equipment may be required before commencing such operations. Therefore, inspection of the dehydrating breather and replacement of the moisture absorbing agent may require shut down of the plant in which the power electrical device is installed causing lost production and increased service cost.”

As a supplement to the background information on this patent, NewsRx correspondents also obtained the inventor’s summary information for this patent: “An object of the invention is to provide a cost-effective solution for liquid immersed power electrical devices in wind turbine installations.

“This is achieved with a wind turbine installation according to a first aspect of the invention, the wind turbine installation comprising a tower, a nacelle, a liquid immersed power electrical device having an expansion vessel, an air dehydrating breather comprising a moisture absorbing agent and a conduit fluidly connecting the expansion vessel and the air dehydrating breather. The wind turbine installation comprises a barrier separating a restricted zone from a non-restricted zone in said wind turbine installation. The electrical device is located in the restricted zone. The air dehydrating breather is located in the non-restricted zone. The conduit extends through the barrier.

“The restricted zone may be limited only to enclose the power electrical device, such most of the wind turbine installation equipment resides in the non-restricted zone. In this way the power electrical device can remain energized when personnel are working on wind turbine equipment in the non-restricted zone, for example most of the nacelle, tower or associated external housings for electrical devices. The placement of the dehydrating breather in the non-restricted zone therefore does not require personnel to be qualified for working in the proximity of high voltage equipment for performing the action of inspecting and replacing the moisture absorbing agent when required. This also makes it possible to use a less costly non-regenerating moisture absorbing agent. Moreover, costly training of personnel can be avoided.

“Moreover, it is not necessary to disconnect the wind turbine installation from the grid. This switching operation can also be costly and time consuming. Thus, further savings on cost and time are achieved with the invention.

“Non-limiting examples of power electrical devices are power transformers, chokes, converters et cetera.”

The claims supplied by the inventors are:

“1. A wind turbine installation comprising a tower, a nacelle, a liquid immersed power electrical device having an expansion vessel, an air dehydrating breather comprising a moisture absorbing agent, and a conduit fluidly connecting the expansion vessel and the air dehydrating breather, wherein the wind turbine installation comprises a barrier separating a restricted zone from a non-restricted zone in said wind turbine installation, wherein the electrical device is located in the restricted zone, wherein the air dehydrating breather is located in the non-restricted zone and wherein the conduit extends through the barrier.

“2. The wind turbine installation according to claim 1, wherein the restricted zone and non-restricted zones are located in the tower.

“3. The wind turbine installation according to claim 1, wherein the restricted zone and non-restricted zones are located in the nacelle.

“4. The wind turbine installation according to claim 1, wherein the wind turbine installation further comprises a housing for the electrical device, wherein the housing is located external to the tower and nacelle, wherein the restricted zone and the non-restricted zones are located in the housing.

“5. The wind turbine installation according to claim 1, wherein the electrical device is a transformer.

“6. The wind turbine installation according to claim 1, wherein the air dehydrating breather comprises a moisture absorbing means, wherein the moisture absorbing means is of a type with no or a finite regeneration capability.

“7. A method of maintaining a wind turbine installation, the wind turbine installation comprising a tower, a nacelle, a liquid immersed power electrical device having an expansion vessel, an air dehydrating breather comprising a moisture absorbing agent, and a conduit fluidly connecting the expansion vessel and the air dehydrating breather, wherein the wind turbine installation comprises a barrier separating a restricted zone from a non-restricted zone in said wind turbine installation, wherein the electrical device is located in the restricted zone, wherein the air dehydrating breather is located in the non-restricted zone and wherein the conduit extends through the barrier, wherein the method comprises regenerating the dehydrating breather without de-energizing the electrical device.”

For additional information on this patent, see: Hillebrandt, Jesper. Wind turbine and method of maintaining a wind turbine. U.S. Patent Number 11319936, filed November 6, 2019, and published online on May 3, 2022. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=11319936.PN.&OS=PN/11319936RS=PN/11319936

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