Transformer assembly

1. A transformer assembly comprising:

an electrical transformer having a transformer tank;

a housing inside which said transformer tank is accommodated, wherein the space between said transformer tank and said housing contains a gaseous atmosphere; and

conditioning means adapted to regulate a level of oxygen of said gaseous atmosphere inside said space equal to or below a first predefined threshold at a first status of said electrical transformer, and equal to or above a second predefined threshold at a second status of said electrical transformer.

2. The transformer assembly according to claim 1 , wherein said conditioning means comprise:

a device adapted to introduce into said space a gas or mixtures of gases having a desired quantity of oxygen.

3. The transformer assembly according to claim 2 , wherein said conditioning means comprise:

a device adapted to introduce into said space a gas or mixtures of gases having a quantity of oxygen lower than that of ambient air.

4. The transformer assembly according to claim 2 , wherein said conditioning means comprise:

a device adapted to introduce into said space a gas or mixtures of gases having a quantity of oxygen equal to or higher than that of ambient air.

5. The transformer assembly according to claim 2 , wherein said device comprises:

a hypoxic air generator.

6. The transformer assembly according to claim 1 , wherein said conditioning means comprise:

a sensor for detecting oxygen inside said space.

7. The transformer assembly according to claim 1 , wherein said conditioning means comprise:

a pressure sensor for monitoring pressure of the gaseous atmosphere contained inside said space.

8. The transformer assembly according to claim 1 , wherein said conditioning means comprise:

at least one opening located on said housing, said opening being provided with a panel moveable between a first closed position at said first status of the electrical transformer and a second open position at said second status of the electrical transformer.

9. The transformer assembly according to claim 8 , wherein said panel is provided with a protection device for preventing movement of the panel from said second closed position to said first open position until the level of oxygen inside said space is below said second predefined threshold.

10. The transformer assembly according to claim 1 , wherein said housing comprises:

at least one side wall having a minimum thickness (T) and positioned at a minimum distance (D) from a corresponding facing side wall of the tank, wherein a ratio between said minimum thickness (T) and said minimum distance (D) is between 0.0001 and 100.

11. The transformer assembly according to claim 10 , wherein said housing comprises:

a plurality of side walls, wherein each side wall of said plurality of side walls has a respective minimum thickness (T 1 , T 2 , . . . T n ) and is positioned at a respective minimum distance (D 1 , D 2 , . . . D n ) from a corresponding facing wall of said tank, wherein each ratio (T 1 /D 1 , T 2 /D 2 , . . . T n /D n ) between each respective minimum thickness (T i of a side wall of said housing and a respective minimum distance (D i ) from the corresponding facing wall of the tank is between 0.0001 and 100.

12. The transformer assembly according to claim 10 , comprising:

a plurality of reinforcing walls, each of which is positioned between a side wall of the housing and the corresponding facing side wall of the tank.

13. The transformer assembly according to claim 12 , comprising:

a plurality of transverse reinforcing walls, each of which is positioned in the space delimited by a side wall of the housing, the corresponding facing side wall of the tank and two adjacent reinforcing walls positioned therebetween.

14. The transformer assembly according to claim 12 , wherein two adjacent reinforcing walls are spaced apart from each other by a minimum distance (L) which is shorter than the distance (D) between a side wall of the housing and the corresponding facing side wall of the tank between which said two adjacent reinforcing walls are positioned.

15. The transformer assembly according to claim 1 , wherein said housing is substantially airtight.

16. The transformer assembly according to claim 1 , wherein said housing is an explosion-proof enclosure.

17. The transformer assembly according to claim 1 , comprising:

noise dampening means which are positioned on a base wall of said housing, said tank resting on said noise dampening means.