Electrical energy transmission device and the design thereof

Abstract

The invention relates to a method for designing an electrical energy transmission device (3). In the method, a service life is specified for the electrical energy transmission device (3). The electrical energy transmission device (3) is configured according to the specified service life in that a temporal and spatial load distribution of loads (B) acting on the electrical energy transmission device (3) is determined, and the electrical energy transmission device (3) is designed according to the load distribution in such a way that its service life corresponds to the specified service life.

Description

[0001] Description

[0002] Electrical energy transmission equipment and its construction

[0003] The invention relates to a method for constructing an electrical energy transmission device. Furthermore, the invention relates to an electrical energy transmission device.

[0004] The electrical power transmission device comprises, for example, a gas-insulated switchgear, a transformer, a generator, and / or a turbine. In particular, the invention relates to an electrical power transmission device that is attached to a moving object. The attachment to the object is realized, for example, using frames, screws, and / or welds. Such an object is, for example, a platform that is floatable and / or anchorable to the seabed. The movements of the object exert forces on the electrical power transmission device, including its attachment to the object. These forces must be taken into account when designing the electrical power transmission device.

[0005] An electrical power transmission device is designed statically and dynamically. The focus is usually on a deterministic service life assessment with a constant load amplitude, the so-called maximum load level. In other words, the electrical power transmission device is designed such that it remains functional over a specified service life if it is constantly exposed to a load at the maximum load level throughout its service life.

[0006] The invention is based on the object of providing an improved method for constructing an electrical energy transmission device and an improved electrical energy transmission device. This object is achieved according to the invention by a method having the features of claim 1 and an electrical energy transmission device having the features of claim 14.

[0007] Advantageous embodiments of the invention are the subject of the dependent claims.

[0008] The method according to the invention for constructing an electrical energy transmission device provides that s

[0009] - a service life is specified for the electrical energy transmission equipment

[0010] - and the electrical energy transmission device is designed according to the specified service life by

[0011] - a temporal and spatial load distribution of loads acting on the electrical energy transmission device is determined and

[0012] - the electrical energy transmission device is designed in accordance with the load distribution in such a way that its service life corresponds to the specified service life.

[0013] The method according to the invention takes into account that an electrical energy transmission device is often not subjected to a constant load throughout its service life, but that the load on the electrical energy transmission device can vary spatially and temporally. With a spatial variation in the load, for example, different areas of the electrical energy transmission device are subjected to different loads. With a temporal variation in the load, the load changes as a function of time.The invention provides for taking spatial and temporal variation in the load into account in the design of the electrical energy transmission device by determining a temporal and spatial load distribution of the electrical energy transmission device and designing the electrical energy transmission device in such a way that its service life corresponds as closely as possible to a predetermined service life when it is loaded in accordance with the load distribution during its service life. In particular, the design of the electrical energy transmission device is therefore not based on a maximum load that remains constant over its service life and for which the electrical energy transmission device is designed.Such a design of the electrical energy transmission device would lead to an over-dimensioning of the electrical energy transmission device in the case of a time-varying load, which would entail unnecessary costs and an unnecessarily high use of materials.

[0014] In one embodiment of the method according to the invention, forces and / or stresses and / or accelerations of at least one region of the electrical energy transmission device are determined as loads acting on the electrical energy transmission device.

[0015] In a further embodiment of the method according to the invention, the service life of the electrical energy transmission device is determined by an accumulation of damage to the electrical energy transmission device which is to be expected due to loads corresponding to the load distribution.

[0016] This embodiment of the method according to the invention takes into account the fact known from material science that repeated loads such as forces or tensions acting on a material object over a longer period of time can lead to fatigue of the material of the object, since with each load a corresponding

[0017] Damage is added to the existing damage. The damage is often not visible at first and originates in the microstructure of the material. This is referred to as damage accumulation over an effective loading period. Different load levels generally make different contributions to the damage accumulation. The mechanical structure of the object therefore has a load-dependent mechanical lifetime, which depends in particular on the spatial and temporal distribution of the loads.

[0018] In a further embodiment of the method according to the invention, a maximum load level of loads on the electrical energy transmission device to be expected during the predetermined service life is determined and the load distribution is determined as a statistical distribution function whose maximum is the maximum load level.

[0019] In this embodiment of the method according to the invention, the load distribution is determined as a statistical distribution function that is adapted to the maximum load level of the electrical power transmission device expected during the specified service life. The statistical distribution function takes into account, for example, location influences acting on the electrical power transmission device and depicts a temporal progression of the loads on the electrical power transmission device with sufficient accuracy.

[0020] In an alternative embodiment of the method according to the invention to the aforementioned embodiment, at least one spectral power density function of loads on the electrical energy transmission device is determined, and the load distribution is determined as a statistical distribution function based on the spectral power density function. In this embodiment of the method according to the invention, the load distribution is also determined as a statistical distribution function. However, the statistical distribution function is not adapted to a maximum load level of loads on the electrical energy transmission device, but is based on at least one spectral power density function.A spectral power density function is determined, for example, by a Fourier transformation of a temporal load profile of the electrical power transmission system. The temporal load profile is determined by measurements or calculations, such as simulations. A spectral power density function can be determined for different areas of the electrical power transmission system.

[0021] In an alternative embodiment of the method according to the invention to the two aforementioned embodiments, the load distribution is determined on the basis of real time-dependent load data of loads acting on the electrical energy transmission device.

[0022] In this embodiment of the method according to the invention, the load distribution is therefore not determined as a statistical distribution function but based on real time-dependent load data.

[0023] In a further embodiment of the method according to the invention, the electrical energy transmission device is attached to a moving object. For example, the movements of the object are caused by repeatedly applying pulses of varying strength to the object.

[0024] This embodiment of the method according to the invention is specifically directed at an electrical energy transmission device that is loaded by the movements of an object to which the electrical energy transmission device is attached. The movements of the object transmit forces and stresses to the electrical energy transmission device. In this case, the load distribution of loads acting on the electrical energy transmission device can also include loads acting on the attachment of the electrical energy transmission device to the object, for example, on welded or screwed connections with which the electrical energy transmission device is attached to the object.

[0025] The moving object is, for example, a platform that is buoyant and / or anchorable to the seabed. In this case, the load distribution takes into account, for example, a statistical distribution of water waves acting on the moving object.

[0026] A floating platform and / or one that can be anchored to the seabed can be any object to which the electrical power transmission device is attached, for example, a ship. Water waves exhibit a characteristic statistical distribution, for example, with regard to their amplitudes (wave heights) and wavelengths. Therefore, water waves acting on the object cause corresponding forces acting on the electrical power transmission device, resulting in a load distribution on the electrical power transmission device that follows the statistical distribution of the water waves.

[0027] Furthermore, the moving object can be a wind turbine. In this case, the load distribution also takes into account, for example, a statistical distribution of wind forces acting on the wind turbine. The wind turbine can, in particular, be an offshore wind turbine and thus also a floating platform and / or one anchored in the seabed in the above sense. In this case, the load distribution takes into account not only the statistical distribution of wind forces but also a statistical distribution of water waves acting on the wind turbine.

[0028] In a further embodiment of the method according to the invention, the electrical energy transmission device comprises a gas-insulated switchgear, a transformer, a generator and / or a turbine.

[0029] An electrical energy transmission device according to the invention is constructed using the method according to the invention.

[0030] The above-described properties, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more readily understood in connection with the following description of exemplary embodiments, which are explained in more detail in connection with the drawings, in which:

[0031] FIG 1 shows a schematic sectional view of an electrical energy transmission device attached to an object,

[0032] FIG 2 is a flow diagram of an embodiment of the method according to the invention,

[0033] FIG 3 is a diagram showing the load of an electrical power transmission device as a function of time,

[0034] FIG 4 is a diagram of a spectral power density function of a load of an electrical energy transmission device.

[0035] Corresponding parts are provided with the same reference numerals in the figures. Figure 1 (FIG 1) shows a schematic sectional view of an electrical energy transmission device 3 attached to a moving object 1. The object 1 is, for example, a platform that is floatable and / or anchorable to a seabed. The electrical energy transmission device 3 comprises, for example, a gas-insulated switchgear, a transformer, a generator and / or a turbine. Furthermore, the electrical energy transmission device 3 comprises a housing 5 and a support structure with a plurality of supports 7, via which the housing 5 is attached to the object 1.

[0036] Each support 7 is connected to the object 1 by a welded connection with at least one weld seam 9. Furthermore, each support 7 is connected to the housing 5 by a screw connection with at least one screw 11.

[0037] Figure 2 (FIG 2) shows a flow diagram of an embodiment of the method according to the invention with method steps 13, 14, 15 for constructing an electrical energy transmission device 3.

[0038] In a first method step 13, a service life is specified for the electrical energy transmission device 3. The service life depends, among other things, on the type of electrical energy transmission device 3, the requirements of the electrical energy transmission device 3, and the conditions prevailing in the environment of the electrical energy transmission device 3. For example, a service life of several years or decades is specified.

[0039] After the first method step 13, the electrical energy transmission device 3 is designed according to the specified service life. For this purpose, in a second method step 14, a temporal and spatial load distribution of the forces acting on the electrical energy transmission device is determined.

[0040] loads determined.

[0041] The load distribution is determined, for example, by determining a maximum load level of loads on the electrical power transmission device to be expected during the specified service life and by determining the load distribution as a statistical distribution function whose maximum is the maximum load level.

[0042] Alternatively, the load distribution is determined by determining a spectral power density function of loads on the electrical power transmission equipment and determining the load distribution as a statistical distribution function based on the spectral power density function.

[0043] In a further alternative, the load distribution is determined based on real time-dependent load data of loads acting on the electrical energy transmission device.

[0044] For example, forces and / or stresses and / or accelerations of at least one area of ​​the electrical energy transmission device 3 acting on the electrical energy transmission device are determined as loads acting on the electrical energy transmission device.

[0045] In the electrical energy transmission device 3 shown in Figure 1, for example, stresses are determined as loads, which act in a first cross-sectional plane A1 on the housing 5, in a second cross-sectional plane A2 on a screw 11, in a third cross-sectional plane A3 on a support 7, and in a fourth cross-sectional plane A4 on a weld seam 9. The cross-sectional planes A1 to A4 are each perpendicular to the drawing plane of Figure 1.

[0046] Figure 3 (FIG 3) shows an example of a load curve B(t) of a load B as a function of time t. In the example shown in Figure 1, the load B is, for example, a stress in one of the cross-sectional planes A1 to A4, in the case of the cross-sectional plane A1, for example, a stress acting in the housing 5. B maxdenotes the maximum of the load curve B(t) and thus the maximum load level. The loads B are either measured or calculated. A calculation of the loads B is based, for example, on accelerations of object 1. If object 1 is floating, for example, accelerations of object 1 are caused by water waves. Water waves have a characteristic statistical distribution, for example, with regard to their amplitudes (wave heights) and wavelengths. A

[0047] The load B on the electrical power transmission device 3 caused by the water wave is then calculated. Thus, the statistical distribution of the water waves can be used to calculate a load profile B(t).

[0048] Figure 4 (FIG 4) shows an example of a spectral power density function B(f) of a load B as a function of a frequency f. The spectral power density function B(f) is, for example, a Fourier transformation of a load curve s B(t) .

[0049] Finally, in a third method step 15, the electrical energy transmission device 3 is constructed such that its service life corresponds to the specified service life. The service life of the electrical energy transmission device 3 is determined, for example, by an accumulation of damage to the electrical energy transmission device 3 that is to be expected from loads that correspond to the load distribution determined in the second method step 14. In the electrical energy transmission device 3 shown in Figure 1, for example, the thicknesses of the housing 5, the supports 7, the weld seams 9, and the screws 11 are designed such that they can withstand the stresses that correspond to the measured or calculated stress profile in the respective cross-sectional planes A1 to A4 over the specified service life.

[0050] Although the invention has been illustrated and described in detail by means of preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Claims

Patent claims 1. Method for constructing an electrical energy transmission device (3), wherein - a service life is specified for the electrical energy transmission device (3) - and the electrical energy transmission device (3) is designed according to the specified service life by - a temporal and spatial load distribution of loads (B) acting on the electrical energy transmission device (3) is determined and - the electrical energy transmission device (3) is designed according to the load distribution in such a way that its service life corresponds to the specified service life.

2. Method according to claim 1, wherein forces and / or stresses and / or accelerations of at least one region of the electrical energy transmission device (3) are determined as loads (B) acting on the electrical energy transmission device (3).

3. Method according to claim 1 or 2, wherein the service life of the electrical energy transmission device (3) is determined by an accumulation of damage to the electrical energy transmission device (3) which is to be expected due to loads (B) corresponding to the load distribution.

4. Method according to one of the preceding claims, wherein a maximum load level (B max) of loads (B) of the electrical power transmission device (3) and the load distribution is determined as a statistical distribution function, the maximum of which is the maximum load level (B max ) is.

5. Method according to one of claims 1 to 3, wherein at least one spectral power density function (B(f) ) of loads (B) of the electrical energy transmission device (3) is determined and the load distribution is determined as a statistical distribution function based on the spectral power density function (B(f) ).

6. Method according to one of claims 1 to 3, wherein the load distribution is determined on the basis of real time-dependent load data of loads (B) acting on the electrical energy transmission device (3).

7. Method according to one of the preceding claims, wherein the electrical energy transmission device (3) is attached to a moving object (1).

8. The method according to claim 7, wherein the movements of the object (1) are caused by pulses of different strengths repeatedly acting on the object (1).

9. The method according to claim 7 or 8, wherein the moving object (1) is a platform that is buoyant and / or anchorable in a seabed.

10. The method according to claim 9, wherein the load distribution takes into account a statistical distribution of water waves acting on the moving object (1).

11. Method according to one of claims 7 to 10, wherein the moving object (1) is a wind turbine.

12. The method according to claim 11, wherein the load distribution takes into account a statistical distribution of wind forces acting on the wind turbine.

13. Method according to one of the preceding claims, wherein the electrical energy transmission device (3) comprises a gas-insulated switchgear, a transformer, a generator and / or a turbine.

14. Electrical energy transmission device (3) constructed using a method according to one of the preceding claims.

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