Transformer Arrangement And Method For Controlling Pressure In A Liquid-Filled Transformer

Patent metadata

Field	Value
Publication number	US-2018158596-A1
Application number	US-201615580553-A
Country	US
Kind code	A1
Filing date	Jun 22, 2016
Priority date	Jun 25, 2015
Publication date	Jun 7, 2018
Grant date	—

Abstract

A transformer including a transformer tank, an expansion tank, and piping connecting the tanks enabling liquid to flow there between. The piping includes a valve configured for liquid to flow from the transformer to the expansion tank when the pressure is above a predefined first threshold and for preventing the liquid to flow from the transformer to the expansion tank when the pressure is below the first threshold. The valve is also configured for liquid to flow from the expansion to the transformer tank when the pressure is below a predefined second threshold and for preventing the liquid to flow from the expansion to the transformer tank when the pressure is above the predefined second threshold.

First claim

1 . A transformer arrangement comprising:
a transformer tank for a liquid-filled electrical transformer; an expansion tank; and piping, connecting the transformer tank with the expansion tank for enabling liquid of the liquid-filled transformer to flow between the transformer tank and the expansion tank via the piping, the piping including a valve;
wherein the valve is configured for allowing the liquid to flow from the transformer tank to the expansion tank when the pressure of the liquid in the transformer tank is above a predefined first threshold and for preventing the liquid to flow from the transformer tank to the expansion tank when the pressure of the liquid in the transformer tank is below the predefined first threshold;
wherein the valve is configured for allowing the liquid to flow from the expansion tank to the transformer tank when the pressure of the liquid in the transformer tank is below a predefined second threshold and for preventing the liquid to flow from the expansion tank to the transformer tank when the pressure of the liquid in the transformer tank is above the predefined second threshold; and
wherein the expansion tank is positioned relative to the transformer tank such as to allow a top surface of the liquid in the expansion tank to be lower than a top surface of the liquid in the transformer tank.

2 . The transformer arrangement of claim 1 , wherein the valve has an overpressure spring for allowing the liquid to flow from the transformer tank to the expansion tank when the pressure of the liquid in the transformer tank is above the predefined first threshold and for preventing the liquid to flow from the transformer tank to the expansion tank when the pressure of the liquid in the transformer tank is below the predefined first threshold.

3 . The transformer arrangement of claim 1 , wherein the valve has a vacuum spring for allowing the liquid to flow from the expansion tank to the transformer tank when the pressure of the liquid in the transformer tank is below the predefined second threshold and for preventing the liquid to flow from the expansion tank to the transformer tank when the pressure of the liquid in the transformer tank is above the predefined second threshold.

4 . The transformer arrangement of claim 1 , wherein the piping further includes a Buchholz relay between the transformer tank and the valve.

5 . The transformer arrangement of claim 1 , wherein the expansion tank includes a diaphragm for separating the liquid from a gas phase in the expansion tank.

6 . A method performed in a transformer arrangement including a liquid-filled transformer tank and an expansion tank, wherein the expansion tank is positioned relative to the transformer tank such that a top surface of the liquid in the expansion tank is lower than a top surface of the liquid in the transformer tank, the method including:
allowing the liquid to flow from the transformer tank to the expansion tank via piping, when the pressure of the liquid in the transformer tank is above a predefined first threshold by automatically opening a valve of the piping; preventing the liquid to flow from the transformer tank to the expansion tank when the pressure of the liquid in the transformer tank is below the predefined first threshold by automatically closing the valve; and allowing the liquid to flow from the expansion tank to the transformer tank when the pressure of the liquid in the transformer tank is below a predefined second threshold, lower than the first threshold, by automatically opening the valve.

7 . The method of claim 6 , wherein the first threshold is above ambient pressure, e.g. atmospheric pressure, and the second threshold is below ambient pressure.

8 . The transformer arrangement of claim 2 , wherein the valve has a vacuum spring for allowing the liquid to flow from the expansion tank to the transformer tank when the pressure of the liquid in the transformer tank is below the predefined second threshold and for preventing the liquid to flow from the expansion tank to the transformer tank when the pressure of the liquid in the transformer tank is above the predefined second threshold.

9 . The transformer arrangement of claim 2 , wherein the piping further includes a Buchholz relay between the transformer tank and the valve.

10 . The transformer arrangement of claim 2 , wherein the expansion tank includes a diaphragm for separating the liquid from a gas phase in the expansion tank.

11 . The transformer arrangement of claim 3 , wherein the piping further includes a Buchholz relay between the transformer tank and the valve.

12 . The transformer arrangement of claim 3 , wherein the expansion tank includes a diaphragm for separating the liquid from a gas phase in the expansion tank.

13 . The transformer arrangement of claim 4 , wherein the expansion tank includes a diaphragm for separating the liquid from a gas phase in the expansion tank.

Assignees

• Abb Schweiz Ag

Inventors

• Cardona Julian

Classifications

• H01F27/14 Primary

  Expansion chambers; Oil conservators; Gas cushions; Arrangements for purifying, drying, or filling · CPC title

• H01F27/321 Primary

  using a fluid for insulating purposes only · CPC title

• F16K17/196

  spring-loaded · CPC title

• F16K17/04

  spring-loaded · CPC title

• H01F27/02

  Casings · CPC title