DE102020104547A1 - METHOD FOR MONITORING SOIL-STRUCTURAL INTERACTION FOR AN OFFSHORE WIND ENERGY SYSTEM AND OFFSHORE WIND ENERGY SYSTEM - Google Patents

Abstract

Embodiments describe a method for monitoring a soil-structure interaction for an offshore wind energy installation (10), the method comprising: acquiring data from at least one first sensor (11, 12, 13, 14, 15) located on a structure the wind energy installation (10) is arranged above a water level; Acquisition of data from at least one second sensor (16, 17, 18) which is arranged on a structure of the wind energy installation (10) below the water level; and processing the data from the at least one first and second sensors to distinguish between wind-related loads and wave-related loads on the wind energy installation (10).

Description

TECHNICAL AREA

The present disclosure relates to a method for monitoring a soil-structure interaction for an offshore wind energy installation and an offshore wind energy installation. In particular, the invention relates to an offshore wind turbine and an associated method, which has, for example, one or more sensors above a water level and one or more sensors below a water level, so that a distinction can be made between wind-related loads and wave-related loads.

TECHNICAL BACKGROUND

Offshore wind turbines usually have a part or structure that protrudes from the water and a part or structure that is underwater. The underwater part is typically anchored in the ground.

The interaction between the ground and the (supporting) structure for offshore wind turbines is a relevant but difficult task as they face complex loads, with the structure and foundation accounting for a third of the total cost of the offshore system.

The design of such structures is highly complex, as many factors depend on the location within a wind farm (wave period, wind turbulence, etc.) as well as on the size and type of the turbines (cyclical load, operating behavior, etc.) and the design of the support structure (based on gravity, Monopile, tripod, jacket, etc.) that would be installed in each location.

Furthermore, the load transfer from the structure to the ground and its reaction are of great importance for the assessment of the stability of the overall system, i.e. for the anchoring in place.

It is known to calculate wave-wind misalignments and the overturning moments are based on complex simulations. However, these are only partial and mostly focus on vibration measurements and their connection with site-specific and operational conditions. KR101740896B1 relates, for example, to a system and a method for monitoring the structure of offshore wind turbines. A soil-structure interaction can be described via vibration measurements on the mud line and related to various operating conditions via a calculation step, which can later be used to isolate the deviations considered relevant.

It is therefore desirable to improve offshore wind energy plants and wind farms in such a way that the system can be better determined. Ideally, improved offshore wind turbines and wind farms could aim at a (complete) measurement of the system.

SUMMARY

Embodiments of the present disclosure provide a method for monitoring a soil-structure interaction for an offshore wind energy installation according to claim 1 and an offshore wind energy installation according to claim 10.

According to one embodiment of the present disclosure, a method for monitoring a soil-structure interaction for an offshore wind turbine is provided. The method comprises acquiring data from at least one first sensor which is arranged on a structure of the wind turbine above a water level; Acquisition of data from at least one second sensor which is arranged on a structure of the wind turbine below the water level; and processing the data of the at least one first and second sensors to distinguish between wind-related loads and wave-related loads on the wind energy installation.

According to a further embodiment of the present disclosure, an offshore wind energy installation is provided. The offshore wind energy installation comprises at least one first sensor which is arranged on a structure of the wind energy installation above a water level; at least one second sensor which is arranged on a structure of the wind turbine below the water level; and a data processing device which is set up to carry out a method for monitoring a soil-structure interaction of the offshore wind energy installation. The method comprises acquiring data from at least one first sensor which is arranged on a structure of the wind turbine above a water level; Acquisition of data from at least one second sensor which is arranged on a structure of the wind turbine below the water level; and processing the data of the at least one first and second sensors to distinguish between wind-related loads and wave-related loads on the wind energy installation.

Figure list

• 1 eine beispielhafte Offshore-Windenergieanlage gemäß Ausführungsformen;
• 2 ein beispielhaftes Model einer beispielhafte Offshore-Windenergieanlage gemäß Ausführungsformen; und
• 3 ein Ablaufdiagramm zur Illustration eines beispielhaften Verfahrens zur Überwachung einer Boden-Struktur-Interaktion für Offshore-Windenergieanlage gemäß Ausführungsformen.

Embodiments of the invention are shown in the drawings and explained in more detail in the description below. In the drawings show:

• 1 an exemplary offshore wind turbine according to embodiments;
• 2 an exemplary model of an exemplary offshore wind turbine according to embodiments; and
• 3 a flowchart to illustrate an exemplary method for monitoring a soil-structure interaction for offshore wind energy installation according to embodiments.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present disclosure are explained in detail below. The drawings serve to illustrate one or more examples of embodiments. In the drawings, the same reference numerals denote the same or similar features of the respective embodiments. Features that are described as part of one embodiment can also be used in connection with another embodiment, and thus form a further embodiment.

As mentioned above, the load transfer from the structure to the ground and its reaction can be of great importance for the assessment of the stability of the overall system, i.e. for the anchoring in place.

Load transfer from offshore structures can be based on a relationship between overturning moment and dead weight, which is assessed at the sludge level (structure to foundation level). Thus, they can be estimated based on an assessment of the turbine and specific soil properties at the site. This means that wind, waves, 1P (in relation to the rotor) and 3P (in relation to the rotor blades) can be viewed as loads.

Due to the harsh conditions and the low (or no) accessibility of the sensor position in offshore wind turbines, there is traditionally little monitoring field data. Dynamic changes in soil stiffness and a mud level as well as site-specific wind wave conditions are difficult to take into account in order to optimize the construction and monitoring of the structure. However, it is absolutely desirable to be able to monitor progressive foundation and building inclination, wave deviation and changes in the natural frequency.

Due to the random nature of wind and wave loads (with the exception of the phenomenon of wind-wave misalignment or wind-wave deviation), the complexity of directly measuring the overturning moment at the sludge level, the low reliability of measurements on an electrical basis and the With limited accessibility from offshore locations, monitoring systems are often based on vibration measurements that are placed in accessible locations in the structure. Wind-wave deviation and the interaction between turbines and structure are usually assessed in very complex simulation environments. Wind turbine and support structures are typically tested on a small scale to better understand dynamic behavior.

Embodiments of the present disclosure can detect and numerically evaluate important aspects for assessing the soil-structure interaction in offshore wind turbines. Both the wind turbine blades and the supporting structure at the mud boundary can be assessed in real time. Embodiments use in particular fiber optic sensors to measure bending moments, pressure moments and vibrations in each axis. In this way, the effects of wind-wave deviation, 1P (relating to the rotor) and 2 / 3P (relating to the blades) as well as the changes in the natural frequencies can be combined in a single measuring system and / or evaluation system.

the 1 shows an exemplary wind turbine 10 , especially an offshore wind turbine. Like in the 1 the wind turbine stands 10 in the water and is anchored in the ground via a foundation. The wind turbine 10 so know a structure 32 standing above a water level W. is arranged and a structure 34 that are below the water level W. is arranged on. The structure below the water level in turn knows the foundation 34 on that in the ground below a mud level S. is arranged or attached. The structure 32 above the water level W. can for example be a tower 32 be.

At the wind turbine 10 according to 1 are exemplary several sensors 11 , 12th , 13th , 14th , 15th , 22nd , 24 arranged. The sensors 11 , 12th , 13th , 14th 15th , 22nd , 24 can collect data. The data can be relevant with regard to the operation of the wind energy installation. Furthermore, a data processing device 16 be provided. The data processing device 16 can, for example, in the structure 32 above the water level W. , in particular in the tower, be arranged. The data processing device 16 can process the recorded data. Via a network interface 18th the processed data can be transferred. In particular can the network interface 18th be set up to connect the data processing device to a data network or a further wind energy installation, in particular a nearby wind energy installation. The network interface can be set up to receive from the data processing device 16 to send processed data to an online-based storage and server service and / or the further wind energy installation, in particular the nearby wind energy installation. Furthermore, a (further) analysis can also take place in the online-based storage and server service. The data processing device 16 can, for example, use and / or be a digital processor unit (“DPU”). In addition, other data, such as meteorological data, can also be integrated into the online-based storage and server service in order to be able to carry out a further evaluation.

Sensors 12th , 13th , 14th 15th , 22nd , 24 can be sensors that record measurement data of a wide variety of parameters, for example a rotor, a gearbox, a generator and / or generally a (different) structure, such as a tower, on the wind turbine. One or more sensors can be installed on a wind turbine 11 , 12th , 13th , 14th 15th , 22nd , 24 to be appropriate. Consequently, unless explicitly stated otherwise, at least one sensor or a combination of several sensors should always be assumed for the present disclosure, even if only “sensor” is used in the singular for simpler addressing.

According to the embodiments described herein, a sensor can 11 , 12th , 13th , 14th , 15th , 22nd , 24 be arranged on the wind turbine. The sensor 11 , 12th , 13th , 14th , 15th can be arranged on a rotor blade of the wind energy installation, on a turbine of the wind energy installation, on a transmission of the wind energy installation, on a tower of the wind energy installation, etc., or an external sensor.

For example, the sensor 11 , 12th , 13th , 14th , 15th , 22nd , 24 be an optical sensor. According to embodiments described herein, the sensor, 12th , 13th , 14th , 15th , 22nd , 24 be a fiber optic sensor. In particular, the sensor, 12th , 13th , 14th , 15th can be a fiber optic strain sensor or acceleration sensor. The reliability of fiber optic sensor technology can promote or enable measurement under harsh offshore conditions.

The sensor 11 , 12th , 13th , 14th , 15th , 22nd , 24 can with the data processing device 16 be connected. For example, the sensor 11 , 12th , 13th , 14th , 15th , 22nd , 24 via a wired or wireless connection to the data processing device 16 be connected. Are the sensor 11 , 12th , 13th , 14th , 15th , 22nd , 24 and the data processing device 16 on mutually movable parts of the wind turbine 10 arranged, such as the rotor and the nacelle, a wireless connection can be advantageous. A wireless connection can be implemented, for example, via radio, in particular via a Bluetooth standard or WLAN standard.

According to the embodiments described herein, at least one of the sensors 11 , 12th , 13th , 14th , 15th on the structure 32 the wind turbine 10 above the water level W. be arranged. These above the water level W. arranged sensors can also be referred to as first sensors or first sensor set. According to the embodiments described herein, at least one of the sensors 22nd , 24 on the structure 34 the wind turbine 10 below the water level W. be arranged. These below the water level W. arranged sensors can also be referred to as second sensors or second sensor set. In particular, the at least one second sensor 22nd , 24 on the structure 34 between water level W. and mud level 36 be arranged. In addition or as an alternative, the at least one second sensor can 22nd , 24 on the structure 34 at the height of the sludge level 36 be arranged. For example, a second sensor can be installed at the height of the sludge level 36 and a further, second sensor can be arranged a little higher.

The offshore wind turbine 10 can therefore in particular the at least one first sensor 11 , 12th , 13th , 14th , 15th standing on a structure of the wind turbine 10 is arranged above the water level, the at least one second sensor 22nd , 24 standing on a structure of the wind turbine 10 is arranged below the water level, and the data processing device 16 which is set up to carry out a method for distinguishing between wind-related loads and wave-related loads on the wind energy installation 10 , exhibit. In particular, through the combination of sensors arranged above and below the water level, a distinction can be made as to whether the sensors are directed to the wind energy installation 10 acting loads are wind-related or wave-related.

According to the embodiments described herein, the at least one first sensor 11 , 12th , 13th , 14th , 15th on a rotor, a rotor blade, a scar and / or a tower section above the water level W. be arranged. According to the embodiments described herein, the at least one second sensor 22nd , 24 on a tower section below the water level W. be arranged. This allows both the influence be recorded by wind as well as waves - or sea movements in general.

According to the embodiments described herein, the at least one first sensor 11 , 12th , 13th , 14th , 15th and / or the at least one second sensor 22nd , 24 be fiber optic sensors. According to the embodiments described herein, the at least one first sensor 11 , 12th , 13th , 14th , 15th and / or the at least one second sensor 22nd , 24 Be vibration sensors, pressure sensors and / or bending moment sensors.

The one on the wind turbine 10 Acting wind and waves can cause vibrations and bending moments on the structures of the wind turbine 10 to lead. Furthermore, pressure in profiles can also be associated with the aerodynamics, which can be converted into mechanical loads. It can therefore be desirable to detect vibrations, pressure and / or bending moments in order to monitor a soil-structure interaction in an offshore wind turbine.

According to embodiments described herein, the data processing device 16 be set up to determine natural frequencies and / or to determine a change in natural frequencies. In particular, the natural frequencies of the structures to which a sensor is connected and / or to which a sensor is attached can be determined and monitored for changes.

According to the embodiments described herein, the monitoring can also lead to a deviation of the wind energy installation from normal behavior being able to be determined. For example, the data from the sensors can be used to determine whether they are in a normal range. Alternatively or additionally, deviations of the wind energy installation from normal behavior can also be carried out based on the natural frequencies. In particular, based on the natural frequencies, normal operating states can be classified as distinct from abrupt, abnormal states and a trend behavior can be identified.

According to embodiments described herein, the data processing device 16 be set up to determine the wind-wave deviation, an angle of inclination of the structure and / or a tilting moment. In particular, the angle of inclination of the structure can be estimated on the basis of a bend in a support structure and / or the tower.

2 shows an example of a model for representing the wind turbine using springs. Both the left and right sides of the 2 show a wind turbine 10 . The wind turbine is on the left 10 for example with the first sensors 14th , 15th and second sensors 22nd shown. The right-hand side shows a model for representing the forces acting on the wind energy installation using a spring model.

The wind turbine 10 is exemplary with the first three sensors 15th shown, each on a corresponding rotor blade 15th are arranged. Furthermore, the wind turbine 10 for example with a first sensor 14th shown, which is arranged on the scar. These sensors can measure the wind-related influences (for example by M _wind shown).

The wind turbine 10 is exemplary with a second sensor 22nd shown, which is arranged on the tower structure below the water level, in particular at the level of the mud level. These sensors can measure the wave-related influences (for example by M _overturning shown).

On the right side of the 2 is the same wind turbine 10 now shown as a spring model. In the model, the interaction of the wind energy installation with the ground, in particular at the level of the mud level, can be represented using a three-spring model or a multi-spring model. A spring in the longitudinal direction of the tower can be viewed as anchored in the ground by the foundation. This spring can be used to represent a movement along the tower. In addition, two springs (although not in the Figure 2 shown) lie in a plane perpendicular to the first spring. These springs can in particular be aligned orthogonally to one another and to the first spring. Another spring can be represented as a spiral spring, which describes a deflection around a pivot point.

Without wishing to be tied to this model, you can use the on the wind turbine 10 arranged sensors, for example, a deflection of the wind turbine 10 can be determined from the (resting) center (see the dashed lines on the right-hand side of the 2 ). In particular, by means of the embodiments described herein, a distinction can be made between wind-related loads and wave-related loads on the wind energy installation, which are responsible for these movements.

According to embodiments described herein Recorded data can be processed in such a way that a wind-wave deviation, an angle of inclination of the structure and / or a tilting moment can be determined. Additionally or alternatively, recorded data can be processed in such a way that vibrations can be determined as a function of a direction. The direction can depend in particular on the wind and wave direction. For example, the angle of inclination of the structure can be estimated on the basis of the bends in the structure or support structure and / or the tower.

3 shows a flow chart to illustrate a method 40 for monitoring a soil-structure interaction for an offshore wind turbine 10 according to embodiments. The wind turbine 10 For example, the wind turbine can 10 the end 1 and 2 be.

According to a box 41 the method includes acquiring data from at least one first sensor 11 , 12th , 13th , 14th , 15th on, which is on a structure of the wind turbine 10 above a water level W. is arranged. According to a box 42 , the method comprises collecting data from at least one second sensor 22nd , 24 on, which is on a structure of the wind turbine 10 below the water level W. is arranged. According to a box 43 , the method has a processing of the data of the at least one first and second sensors in order to distinguish between wind-related loads and wave-related loads on the wind energy installation.

According to the embodiments described herein, most of the relevant stress factors can be measured in order to assess an interaction between soil (mud) and structure (in particular wind loading in the blades, overturning at the mud boundary and a vibration level both in the rotor and in the bottom of the structure ).

SCADA data and / or meteorological data can be used for evaluation, in particular numerical evaluation. In particular, SCADA data can be used to classify normal operating conditions as distinct from abrupt, abnormal conditions and to identify trend behavior. Meteorological data can be used, for example, to predict storms, which can also be passed on to other systems and integrated. For example, energy production can be optimized for mechanical loads in this way.

In particular, the reliability of fiber optic sensor technology can improve or enable measurement under rough offshore conditions.

Embodiments described herein can in particular bring one or more advantages of the following advantages with them, which can arise with regard to the particular challenge of offshore wind turbines:

System reliability: fiber optic sensors have a high intrinsic reliability, which makes them ideal for offshore use.

Wind load: if sensors are placed in the leaves, for example, the entire load chain is available to estimate the wind-wave deviation and trend.

Sludge level measurements: if sensors are arranged e.g. at the height of the sludge level, the soil-structure interaction can be evaluated with the tilting moment and vibration.

Complete load chain: the analysis of bending moments, pressure and vibrations from the (entire) wind-structure-floor structure can be summarized.

The use of fiber optic sensors can introduce the advantages of the measurement principle.

The evaluation of the (entire) load chain, both at the interface between wind and structure and also at the interface between soil and structure.

The distinction between wind / rotor-dependent and shaft / ground-dependent loads in a single system.

It should be pointed out at this point that the aspects and embodiments described herein can be appropriately combined with one another, and that individual aspects can be omitted where it makes sense and is possible within the scope of professional practice. Modifications and additions to the aspects described herein are familiar to the person skilled in the art.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• KR 101740896 B1 [0006]

Claims (17)

A method for monitoring a soil-structure interaction for an offshore wind energy installation (10), the method comprising: Acquisition of data from at least one first sensor (11, 12, 13, 14, 15) which is arranged on a structure of the wind energy installation (10) above a water level; Acquisition of data from at least one second sensor (22, 24) which is arranged on a structure of the wind energy installation (10) below the water level; and Processing of the data from the at least one first and second sensors to distinguish between wind-related loads and wave-related loads on the wind energy installation (10). Procedure according to Claim 1 , wherein the at least one first sensor and / or the at least one second sensor are fiber optic sensors. Procedure according to Claim 1 or 2 , wherein the at least one first sensor is arranged on a rotor, a rotor blade, a scar and / or a tower section above the water level. Method according to one of the preceding claims, wherein the at least one second sensor is arranged on a tower section below the water level. Method according to one of the preceding claims, wherein the at least one first sensor measures vibrations, pressure and / or bending moments. Method according to one of the preceding claims, wherein the at least one second sensor measures vibrations, pressure and / or bending moments. Method according to one of the preceding claims, wherein the processing of the data comprises determining natural frequencies. Method according to one of the preceding claims, wherein a wind-wave deviation, an angle of inclination of the structure, a tilting moment and / or vibrations as a function of a direction can be determined by processing the data. Method according to one of the preceding claims, wherein a deviation of the wind energy installation from normal behavior can be determined by processing the data. Method according to one of the preceding claims, further comprising: Sending the processed data to an online-based storage and server service (20) via a data network, in particular for analyzing the data in the online-based storage and server service (20). Offshore wind energy installation (10), comprising: at least one first sensor (11, 12, 13, 14, 15) which is arranged on a structure of the wind energy installation (10) above a water level; at least one second sensor (22, 24) which is arranged on a structure of the wind energy installation (10) below the water level; and a data processing device (16) which is set up to carry out the method according to any one of the preceding claims. Wind turbine after Claim 11 , wherein the at least one first sensor and / or the at least one second sensor are fiber optic sensors. Wind turbine after Claim 11 or 12th , wherein the at least one first sensor is a vibration sensor, pressure sensor and / or bending moment sensor. Wind energy installation according to one of the preceding claims, wherein the at least one second sensor is a vibration sensor, pressure sensor and / or bending moment sensor. Wind energy installation according to one of the preceding claims, wherein the structure arranged above the water level is a rotor, a rotor blade, a scar and / or a tower section above the water level. Wind energy installation according to one of the preceding claims, wherein the structure arranged below the water level is a tower section below the water level. Wind energy installation according to one of the preceding claims, wherein the data processing device (16) uses a digital processor unit (“DPU”).

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