[0001] The invention is related to an oil transformer, comprising a high voltage transformer
arranged in an oil filled vessel, an expansion vessel, a fluidic connection in between
the expansion vessel and the oil filled vessel and at least one cooling means.
[0002] It is known, that transformers, reactors and other electrical devices used in HV
transmission networks of for example 380kV are typically arranged within an oil filled
vessel. The oil is on one hand insulation medium and on the other hand cooling medium.
An expansion vessel is fluidic connected with the oil filled vessel in order to handle
the thermal expansion of the oil which arises during operation of the respective HV
component, for example an oil transformer. In the frame of this invention the wording
"transformer" has also to be seen as synonym for a reactor and the wording "oil" covers
also comparable insulation fluids such as Ester. Typically cooling means are foreseen
for cooling the oil transformer, mainly heat exchangers, in particular an oil air
heat exchanger or an oil water heat exchanger, or radiators which might be arranged
as a radiator battery.
[0003] An HV oil transformer might have a rated power of several 100MVA, a weight of several
100t, a height of for example 6m and above and a length of 12m and above. Thus the
transportation of such an oil transformer from the factory to site is a challenging
task. In order to facilitate transportation, the attached components such as cooling
means and expansion vessel are transported separately and assembled together with
the main part of the oil transformer on site.
[0004] Disadvantageously within the state of the art is that the attached components are
normally individually designed with respect to individual requirements for the respective
oil transformer. Thus the attached components typically differ in size and shape so
that as well their transport as their assembly on site is rather individual and time
consuming therewith. Also seismic requirements, for example with respect to groundwork
and a stable arrangement, have to be fulfilled when assembling the components to be
attached on site.
[0005] The objective of the invention is to provide an oil transformer with attached components,
which are easier to transport and to easier assemble on site.
[0006] The problem is solved by an oil transformer of the aforementioned kind. This is characterized
in that at least the expansion vessel is fixedly integrated in a mechanical supporting
structure having four upper and four lower corner points arranged in the form of a
square, wherein the corner points each are in the form of load transfer points and
are arranged according to the dimensions of a CSC container. CSC means Container Safety
Convention wherein the standards related thereto are described for example in ISO
668.
[0007] Basic idea of the invention is to modularize the components to be attached to an
oil transformer, for example an expansion vessel or the like. All modules have in
common, that they are designed in that way, that they can be transported exactly like
a CSC container. A module comprises a mechanical supporting structure with outer dimensions
like a CSC container and a component of an oil transformer fixedly integrated therein.
[0008] CSC containers are a widely known and standardized transportation medium. A CSC container
complies with standardized dimensions, for example a standardized length of 6,058m
or 12,192m, wherein the height amounts 2,591 m and the width 2,438m. A transport by
ships, trucks or train to any location in the world is possible without any problem.
Thus the transportation of the components to be attached to an oil transformer is
facilitated therewith compared to the transportation in bulky cases as it is common
now.
[0009] According to the invention a respective component to be attached to an oil transformer
is fixedly integrated in the mechanical supporting structure, which is not only of
advantage for an easier transportation, moreover an easier installation on site is
enabled therewith. The mechanical supporting structure enables an easy placing on
site on the four lower corner points. Any complex groundwork is as less required as
a direct assembly with the vessel of the oil transformer. It is also possible to stack
the mechanical supporting structures of several modules easily each on each other.
Only respective fluidic connections in between the oil filled transformer vessel and
the respective mechanical supporting structure have to be mounted on site.
[0010] Typically the mechanical supporting structure is designed in that way, that it has
a comparable life cycle than the oil transformer itself, so that the components fixedly
integrated in the mechanical supporting structure can permanently remain therein.
[0011] According to a further embodiment of the invention the mechanical supporting structure
of the expansion vessel comprises coupling means at its outer surface which are foreseen
as a part of the fluidic connection in between the expansion vessel and the oil filled
vessel. The first part of the fluidic connection in between the expansion vessel and
the coupling means is integrated in the mechanical supporting structure. So the second
part from the coupling means to the oil filled vessel can easily be carried out comparable
to a plug and play connection.
[0012] According to another embodiment of the oil transformer the at least one cooling means
are fixedly integrated in a further respective mechanical supporting structure having
four upper and four lower corner points arranged in the form of a square, wherein
the corner points each are in the form of load transfer points and are arranged according
to the dimensions of a CSC container. Integrating also the cooling means into a mechanical
supporting structure of same dimensions increases the flexibility of the modular system.
If required two or more modules with mechanical supporting structure and fixedly integrated
cooling means can be attached to one oil transformer. Due to the identic dimensions
the respective mechanical supporting structures respectively modules can be placed
side by side or stacked each on each other.
[0013] According to a further embodiment of the invention the at least one cooling means
are a heat exchanger, in particular an oil air heat exchanger or an oil water heat
exchanger. In this case a fluidic connection in between the heat exchanger and the
oil filled vessel is required. A heat exchanger has not necessarily to be placed side
by side to the oil filled vessel, but in order to keep the respective fluidic connection
as short as possible it would be at least of advantage to place it in close proximity.
Optionally pumps or other components which are required to operate the heat exchanger
are integrated in the respective module.
[0014] According to a further embodiment of the invention the mechanical supporting structure
of the heat exchanger comprises coupling means at its outer face which are foreseen
as a part of a fluidic connection in between the heat exchanger and the oil filled
vessel. The first part of the fluidic connection in between the cooling means and
the coupling means is integrated in the mechanical supporting structure. So the second
part from the coupling means to the oil filled vessel can easily be carried out comparable
to a plug and play connection.
[0015] According to another embodiment of the invention the at least one cooling means are
one or more radiators. Radiators should be placed at least in close proximity to the
oil filled vessel in order to increase the cooling effect of the air flow caused by
the radiators. Radiators can be arranged as well with horizontal as with vertical
alignment.
[0016] According to another variant of the invention the radiators are divided into two
groups, which are foreseen to be operated independently each from each other. This
enables an easy adaptation of the cooling power to the actual need for cooling.
[0017] According to another embodiment of the invention a respective mechanical supporting
structure comprises at least one hollow bar, which is as well load bearing as foreseen
as a part of the fluidic connection in between the expansion vessel respectively the
cooling means and the oil filled vessel. Thus it is possible to reduce the effort
for the fluidic connection by integrating the functionality of a pipe into the load
bearing hollow bar of the mechanical support structure.
[0018] According to another embodiment of the oil transformer further means - in particular
control equipment - are fixedly integrated in a further respective mechanical supporting
structure having four upper and four lower corner points arranged in the form of a
square, wherein the corner points each are in the form of load transfer points and
are arranged according to the dimensions of a CSC container. This increases once again
the flexibility of the modular system. Even an empty mechanical supporting structure
could be used to lift one or more modules stacked thereon in a suitable height.
[0019] A suitable height for an expansion vessel is above the top of the oil filled vessel.
Considering that the height of a transformer might amount 5m and above the mechanical
support structure with the expansion vessel could be placed on a stack with two other
mechanical supporting structures so that it is in a suitable height. Preferably the
supporting structures below could have cooling means integrated therein, but in case
that there is only need for one mechanical supporting structure with cooling means
the other mechanical supporting structure could be even empty with the only purpose
to lift the stack up.
[0020] Thus according to another embodiment of the invention at least two respective mechanical
supporting structures are stacked each on each other. According to a further embodiment
of the invention a respective mechanical supporting structure with an expansion vessel
is stacked over a respective mechanical supporting structure with cooling means.
[0021] According to another embodiment of the invention at least one supporting structure
is arranged side by side to the oil filled vessel. This reduces the length of the
fluidic connections to the oil filled vessel and in case of the use of radiators as
cooling means the cooling efficiency is increased therewith.
[0022] Further advantageous embodiments of the invention are mentioned in the dependent
claims.
[0023] The invention will now be further explained by means of an exemplary embodiment and
with reference to the accompanying drawings, in which:
Figure 1 shows an exemplary mechanical support structure,
Figure 2 shows a stack of two mechanical support structures and
Figure 3 shows an exemplary oil transformer.
[0024] Figure 1 shows an exemplary mechanical support structure 10, which is carried out
as a truss structure, for example by use of beams respectively hollow beams. The mechanical
support structure has the outer shape of a cuboid which is defined by four upper 12
and four lower 14 corner points. The mechanical support structure comprises a base
frame 16 which is designed in that way that an integrated component such as an oil
filled expansion vessel can be worn. Traverses 18 increase the mechanical stability.
[0025] Figure 2 shows a stack of two mechanical support structures in a sketch 20. A first
22 and a second 24 truss like mechanical support structure are stacked each on each
other. The support structures 22, 24 comprise each four upper 26 and four lower 28
corner points.
[0026] Figure 3 shows an exemplary oil transformer 30. A transformer with a transformer
core 32 and transformer coils 34 is arranged in a vessel 36 which is filled with oil
38. An HV bushing 40 is foreseen at the top of the vessel 36. A stack of mechanical
support structures 46, 48, 50 is foreseen left of the vessel 36. An expansion vessel
42, which is partly filled with oil 44, is integrated in the first mechanical support
structure 46. A fluidic connection in between the expansion vessel 42 and the vessel
36 is realized by a first part 52 leading from the expansion vessel 42 to coupling
means 54 and by a second part 56 leading from the coupling means 54 to the vessel
36.
[0027] The second mechanical support structure 48 has cooling means 58 integrated therein,
in this case a heat exchanger. The heat exchanger comprises several disk like cooling
modules which are arranged side by side along the axial length of the mechanical support
structure 48. Each cooling module is supplied by a main feed line 64 with oil to be
cooled and which is returned after cooling over a main return line 66. Each cooling
module has an own feed 60 and return 62 line which are connected to the respective
main line 64 respectively 66.
[0028] The third mechanical support structure 50 comprises a fan 68 and control equipment
70, in particular a computer for logging and analyzing measured data of the oil transformer
30. Additionally the stack of the first 46 and second 48 mechanical support structures
is lifted up therewith, so that the expansion vessel 42 of the first mechanical support
structure is above the top of the vessel 36 therewith. The whole arrangement is placed
on a ground floor 72.
List of reference signs
[0029]
- 10
- exemplary mechanical support structure
- 12
- upper corner points
- 14
- lower corner points
- 16
- base frame
- 18
- traverse
- 20
- stack of two mechanical support structures
- 22
- upper mechanical support structure
- 24
- lower mechanical support structure
- 26
- upper corner points of upper mechanical support structure
- 28
- lower corner points of lower mechanical support structure
- 30
- exemplary oil transformer
- 32
- transformer core
- 34
- transformer coil
- 36
- vessel
- 38
- oil
- 40
- HV-bushing
- 42
- expansion vessel
- 44
- oil
- 46
- first mechanical support structure
- 48
- second mechanical support structure
- 50
- third mechanical support structure
- 52
- first part of fluidic connection
- 54
- coupling means
- 56
- second part of fluidic connection
- 58
- cooling means
- 60
- feed line of cooling module
- 62
- return line of cooling module
- 64
- main feed line
- 66
- main return line
- 68
- fan
- 70
- control equipment
- 72
- ground floor
1. Oil transformer (30), comprising
• a high voltage transformer (32 + 34) arranged in an oil filled vessel (36),
• an expansion vessel (42),
• a fluidic connection (52 + 54 + 56) in between the expansion vessel (42) and the
oil filled vessel (36),
• at least one cooling means (58),
characterized in that
the expansion vessel (42) is fixedly integrated in a mechanical supporting structure
(10, 22, 24, 46, 48, 50) having four upper (12, 26) and four lower (14, 28) corner
points arranged in the form of a square, wherein the corner points (12, 14, 26, 28)
each are in the form of load transfer points and are arranged according to the dimensions
of a CSC container.
2. Oil transformer according to claim 1, characterized in that the mechanical supporting structure (10, 22, 24, 46, 48, 50) of the expansion vessel
(42) comprises coupling means (54) at its outer surface which are foreseen as a part
of the fluidic connection (52 + 54 + 56) in between the expansion vessel (42) and
the oil filled vessel (36).
3. Oil transformer according to claim 1 or 2, characterized in that the at least one cooling means (58) are fixedly integrated in a further respective
mechanical supporting structure (10, 22, 24, 46, 48, 50) having four upper (12, 26)
and four lower (14, 28) corner points arranged in the form of a square, wherein the
corner points (12, 14, 26, 28) each are in the form of load transfer points and are
arranged according to the dimensions of a CSC container.
4. Oil transformer according to claim 3, characterized in that the at least one cooling means (58) are a heat exchanger, in particular an oil air
heat exchanger or an oil water heat exchanger.
5. Oil transformer according to claim 4, characterized in that the mechanical supporting structure (10, 22, 24, 46, 48, 50) of the heat exchanger
(58) comprises coupling means at its outer face which are foreseen as a part of a
fluidic connection in between the heat exchanger (58) and the oil filled vessel (36).
6. Oil transformer according to claim 3, characterized in that the at least one cooling means (58) are one or more radiators.
7. Oil transformer according to claim 6, characterized in that the radiators are divided into two groups, which are foreseen to be operated independently
each from each other.
8. Oil transformer according to any of the previous claims, characterized in that a respective mechanical supporting structure (10, 22, 24, 46, 48, 50) comprises at
least one hollow bar, which is as well load bearing as foreseen as a part of the fluidic
connection (52 + 54 + 56) in between the expansion vessel (42) respectively the cooling
means (58) and the oil filled vessel (36).
9. Oil transformer according to any of the previous claims, characterized in that further means - in particular control equipment - are fixedly integrated in a further
respective mechanical supporting structure (10, 22, 24, 46, 48, 50) having four upper
(12, 26) and four lower (14, 28) corner points arranged in the form of a square, wherein
the corner points (12, 14, 26, 28) each are in the form of load transfer points and
are arranged according to the dimensions of a CSC container.
10. Oil transformer according to any of the previous claims, characterized in that at least two respective mechanical supporting structures (10, 22, 24, 46, 48, 50)
are stacked each on each other.
11. Oil transformer according to claim 10, characterized in that a respective mechanical supporting structure (10, 22, 24, 46, 48, 50) with an expansion
vessel (42) is stacked over a respective mechanical supporting structure (10, 22,
24, 46, 48, 50) with cooling means (58).
12. Oil transformer according to any of the previous claims, characterized in that at least one supporting structure (10, 22, 24, 46, 48, 50) is arranged side by side
to the oil filled vessel (36).