Electric transformer with improved cooling system

1. An electric transformer, comprising:

a magnetic core;

at least one coil assembly which is positioned around a portion of said magnetic core and comprises a plurality of windings, said coil assembly further comprising a plurality of cooling ducts provided at various positions between adjacent turns of said coil assembly;

a structure adapted for applying a clamping force on said magnetic core and/or windings, said clamping structure comprising at least a first clamping bar; and a cooling circuit comprised of:

said first clamping bar;

one or more pipes which protrude transversely from said first clamping bar; and

a first fluid diffuser having a ring-shaped body with first and second ends, said first end connected to said at least one coil assembly and said second end connected to said one or more pipes, said cooling circuit adapted for allowing cooling fluid to flow through said first clamping bar, said one or more pipes and said first fluid diffuser towards and inside said at least one coil assembly and one or more of said cooling ducts.

2. The electric transformer according to claim 1 wherein said first clamping bar is in fluid communication with the internal part of said at least one coil assembly.

3. The electric transformer according to claim 1 wherein said cooling circuit comprises a pump for pumping cooling fluid from a fluid container into said first clamping bar.

4. The electric transformer according to claim 1 , further comprising one or more guide elements which are positioned inside said at least one coil assembly and are adapted for guiding said cooling fluid into said cooling ducts.

5. The electric transformer according to claim 1 , further comprising a plurality of coil assemblies, each of said coil assemblies comprising a plurality of windings and being positioned around a corresponding portion of said magnetic core, wherein said cooling circuit is adapted for conveying cooling fluid directly inside each of said plurality of coil assemblies.

6. The electric transformer according to claim 5 wherein each of said coil assemblies comprises a plurality of cooling ducts and said cooling circuit is adapted for conveying cooling fluid directly inside one or more cooling ducts of each coil assembly.

7. The electric transformer according to claim 5 wherein said first clamping bar is in fluid communication with the internal part of each coil assembly of said plurality of coil assemblies.

8. The electric transformer according to claim 6 wherein said cooling circuit comprises a plurality of fluid diffusers each of which is operatively connected to an associated coil assembly of said plurality of coil assemblies and is adapted for allowing flowing of the cooling fluid into the cooling ducts of the associated coil assembly.

9. The electric transformer according to claim 8 wherein each fluid diffuser of said plurality of diffusers is connected to said first clamping bar by means of one or more pipes protruding transversely from the first clamping bar.

10. The electric transformer according to claim 1 , wherein said clamping structure comprises a second clamping bar which is part of said cooling circuit and is adapted for allowing flowing of said cooling fluid towards one or more of said coil assemblies.

11. The electric transformer according to claim 10 wherein said second clamping bar is operatively coupled to a pump, said pump for pumping cooling fluid from a fluid container, said second clamping bar is in fluid communication with the internal part of one or more of said plurality of coil assemblies.

12. The electric transformer according to claim 8 wherein each fluid diffuser of said plurality of diffusers is connected to a second clamping bar by means of one or more pipes protruding transversely from said second clamping bar.