DE102009015679A1 - Stationary power generation plant with control device and method for controlling the power generation plant - Google Patents

Abstract

The invention relates to a stationary energy production plant (1) with a control device (7) and a method for controlling the energy production plant (1). For this purpose, the energy production plant (1) has a rotor (2) and a nacelle (3), in which further components of the energy production plant (1) for converting wind energy into electrical energy are arranged. The energy production plant (1) is arranged in a wind field (4) and has a praeaktive wind measuring device (5) mounted on the plant. The praeaktive wind measuring device (5) detects current wind profiles (6) upstream spaced from the power plant (1). The control device (7) has a feedforward control (13) which uses the preactive wind profile measurement (5) in order to minimize loads on the system when the wind field impinges. Remaining loads are measured and further reduced by an IPC controller.

Description

The The invention relates to a stationary power generation plant with a control device and a method for controlling the Energy recovery plant. This is indicated by the energy recovery plant a rotor and a nacelle, in the other components of the power plant arranged to convert wind energy into electrical energy are on. The power generation plant is arranged in a wind field and has a pre-operationally mounted wind measuring device mounted on the system on. The preactive wind measuring device detects current Wind profiles upstream spaced from the power plant. In addition, the power generation plant has additional Sensors on to loads the components of the power plant capture.

From the publication US 7,281,891, B2 For example, there is known a wind turbine controller having a LIDAR wind speed measuring device. The LIDAR device is arranged to scan the area in front of the wind turbine and to generate a measurement of the wind speed in the wind field. The LIDAR device may be located in the hub of the wind turbine. Preferably, the LIDAR device has a plurality of destinations to increase the sampling rate. This can be achieved by a larger number of selected LIDAR systems and / or using a multiplex LIDAR. The measurement of the wind field enables improved control of the wind turbine and results in efficiency and reduced wear.

From the publication EP 1 770 278 A2 For example, a system and method for controlling a wind turbine based on the upstream measurement of wind speeds is known. In this case, the upstream measurement of the wind speed is only used to achieve a performance optimization of the power generation plant by the rotor blades are adjusted via a rotor blade pitch motor according to the measured wind speed.

One Disadvantage of the known devices and methods for electrical Energy production from wind power is that the measured wind fields used for load reduction and performance optimization but the burdens are not covered, so that Although the performance is optimized, but the risk of breakage of the components the power generation plant is increased.

This Disadvantage has a special effect, as the wind changes, until it hits the plant. This creates stronger ones or weaker loads than actually due to the measured wind field would be expected. Likewise must in the previous methods, a calculation method can be used from the measured wind speeds on the load of To close the plant. Again, this method is only approximate right. An adjustment of the angle of attack of the rotor blades or the pitch due to the measured wind parameters can consequently not be used to exact load limits of the components to comply with a wind turbine.

Either must be expected with great certainty and oversized the plant be interpreted or it must be accepted that permissible Loads can be exceeded. Though It is also known, a scheme of the plant to reduce stress based on measured loads on the components of the plant such as B. leaf root moments, moments on the main shaft, etc., but these methods have the disadvantage that the controller only after can react to measuring a load to reactive the loads compensate. However, that means strong changes the wind speed continues to be excessive Loads and ultimately to a reduced life of the system to lead.

in principle So far, a controller of the control device, the measured Loads supplied to the power plant. These are converted to that acting on the nacelle from the rotor Yaw and pitch moment to calculate. These are usually provided two PID controller, which then each have an additional Calculate pitch angle to zero yawing and pitching moment to regulate. The calculated additional pitch angles in the yaw and pitch directions be with a corresponding transformation in the rotating Coordinate system of the rotor converted. This will be for each rotor blade receive an additional pitch angle, the to that of a plant calculator to keep the speed of the plant constant to hold, as a common pitch angle calculated angle for all leaves are added. The rotor blades are then to the respectively required pitch angle by the corresponding Actuators or by the known from the prior art rotor blade pitch motors turned.

task The invention is a stationary power generation plant with control device and a method for controlling the power generation plant to create, which further reduces the burden by the vor the wind field measured for an IPC control (individual pitch control) is used.

This task is with the subject of solved independent claims. Advantageous developments of the invention will become apparent from the dependent claims.

According to the invention a stationary power generation plant with a control device and a method for controlling a power generation plant created. For this purpose, the power generation plant has a rotor and a nacelle on, where in the gondola other components of the power plant arranged to convert wind energy into electrical energy are. The power generation plant is arranged in a wind field and has a pre-operationally mounted wind measuring device mounted on the system on. The preactive wind measuring device captures current wind profiles upstream from the power plant. The control device has a feedforward control auf, which uses the praeaktive wind profile measurement such that the pitch angle of the rotor blades individually preset are that when hitting the pre-reactively measured wind field, the Loads are minimized.

These Energy recovery plant has the advantage that in the control device already existing known control circuit for load reduction means an individual pitch angle adjustment now by a feedforward control is extended. This disturbance variable connection calculates and sets individual pitch angles for each single rotor blade based on parameters, like wind speed, wind shear, horizontal wind direction and vertical wind direction detected by the wind measuring device will be available. As a result, the inventive reaction Energy production plant to appropriate changes in the wind profile, even before loads occur.

• – Messung des Windfeldes vor der Anlage beispielsweise im Abstand von ca. 200 m durch die auf der Anlage montierte Windmessvorrichtung, die eine Vielzahl von Punkten in einem Windfeld abtastet;
• – Filterung der gemessenen Geschwindigkeiten, um Hintergrundrauschen usw. zu unterdrücken;
• – Berechnung der mittleren Geschwindigkeit, mit der sich die Messebene auf die Energiegewinnungsanlage zu bewegt;
• – Verzögerung der Daten, um eine Totzeit t_tot, die sich aus der mittleren Windfeldgeschwindigkeit und dem Abstand der Messebene von der Anlage berechnet;
• – Berechnung eines individuellen Pitchwinkels für jedes einzelne Rotorblatt.

Wind measurement errors are compensated by the control device or by the controller in the control device, which uses the measured loads of the power generation plant as an input signal. Suitable measured variables detected by corresponding sensors are impact or pivoting moments of the rotor blades, pitching or yawing torques of the nacelle and moments in and on the drive train. The preactive wind measurement results are fed to the feedforward control in the control device. The feedforward calculation calculates for each sheet a further pitch angle, which is added to the already existing pitch angles. The disturbance variable conversion takes place as follows:

• - Measuring the wind field in front of the plant, for example, at a distance of about 200 m by the windmill mounted on the system, which scans a plurality of points in a wind field;
• Filtering the measured velocities to suppress background noise, etc .;
• - Calculation of the average speed at which the measuring plane moves towards the energy recovery system;
• - Delay the data to a dead time t _tot , which is calculated from the mean wind field velocity and the distance of the measuring plane of the plant;
• - Calculation of an individual pitch angle for each individual rotor blade.

• – Berechnung der Schubkraft an Blattelementen aus den bekannten demnächst auftretenden Windgeschwindigkeiten sowie den Pitchwinkeln β₁, β₂ und β₃;
• – Integration über das Blatt zur Berechnung des sich daraus ergebenden Blattwurzelmoments;
• – Berechnen des sich ergebenden Nick- und/oder Giermoments auf die Gondel;
• – Vergrößerung oder Verkleinerung der einzelnen Pitchwinkel β₁, β₂, β₃, um die Nick- und/oder Giermomente zu Null zu bringen;
• – Nächste Iteration mit den neuen Pitchwinkeln β₁, β₂, β₃ und schließlich
• – Abbruch der Iteration, wenn die sich ergebenden Nick- und/oder Giermomente nicht weiter minimierbar sind.

For this purpose, an iterative method may be used, wherein the starting point for the pitch angles β ₁ , β ₂ , β _{3 is} the current collective pitch angle of the standard controller, and then

• - Calculation of the thrust on leaf elements from the known soon occurring wind speeds and the pitch angles β ₁ , β ₂ and β ₃ ;
• Integration via the sheet for calculating the resulting leaf root moment;
• - Calculating the resulting pitch and / or yaw moment on the nacelle;
• Increasing or decreasing the individual pitch angles β ₁ , β ₂ , β ₃ in order to bring the pitching and / or yawing moments to zero;
• - Next iteration with the new pitch angles β ₁ , β ₂ , β ₃ and finally
• - Termination of the iteration, if the resulting pitch and / or yaw moments are not further minimized.

by virtue of the feedforward control with help The praeactive wind measuring device should be a major part the resulting from the wind loads are no longer at the Plant occur. The remaining loads due to model errors and / or Parameter errors, etc. are then passed through the existing IPG controller corrected by measuring the loads. This gives a clear Improvement compared to the previous energy production plants.

Should the pitch drives for adjusting the rotor blades too be slow to follow the disturbances May possibly improve the process by doing so be achieved when the feedforward Trajectories are generated for the pitch angles, which are over all already measured and upcoming wind speed conditions cause the smallest control error.

In this case, the control device according to the invention controls the pitch angle so that the measured loads of the components of the power generation plant are minimized. Due to the closed control loop via the direct load measurement, the controller can despite a value measurement or a conversion error despite exactly to the desired load limits. As a result, predetermined load limits can be met accurately and still be fully utilized, so that the energy yield is not limited more than absolutely necessary. The combination of the preactive wind measurement and the load measurements achieves the highest possible service life with the highest possible power output for an energy recovery system.

To in a preferred embodiment of the invention the wind measuring device as a reactive wind sensor system a LIDAR system (light detection and ranging anemometer) or a SODAR system (sound detection and ranging anemometer).

Around the predetermined load limits for the loaded Components of the power generation plant not to exceed has these sensors, which are the loads of the components to capture. The sensors are electrically connected to the control device and / or optically via signal transfer devices.

Furthermore has the control device with the feedforward control a filter with respect to wind speed readings, to suppress a measurement noise. To set limits for the To comply with maximum load, can be extreme when measured proportionally Gusts a pitch or a pitch are given, which spends the rotor blades feathered, wherein a drive train in the nacelle has no more rotation. This can by an additional braking device and / or by a corresponding clutch in the drive train can be achieved.

In addition, it is envisaged that the power generation plant has a computer which determines a mean wind speed and wind direction with the aid of the reactive wind measuring device, with which moves the wind profile to the power plant and calculates a dead time t _tot , up to the wind profile measured at a distance reached the power generation plant.

In A further embodiment of the invention is intended that the rotor blades one from the control unit have predetermined current collective angle of attack and the Feedforward control depending on the preaactive wind profile measurement individual angle of attack for every single rotor blade provides, so that in response to a praeactive Wind profile measurement of the pitch and yaw angles of the nacelle adjusted is that pitching and yawing moments are minimal.

Further it is envisaged that the power generation plant a braking device in a drive train for braking the rotor and / or the waves of the drive train and the controller in response on a wind profile measurement the rotor blades feathered adjusts and slows down the rotor. Furthermore, damping devices for damping vibrations in the drive train of Wind energy device provided, wherein the control device in Response to a wind profile measurement the damping of vibrations in the drive train can change.

One Method for controlling an energy recovery plant, the following steps on. First, a wind profile at a distance upstream of the power plant detected. Subsequently, a dead time until arrival calculated from the wind field at the power plant. A controller uses the measurement results of the wind field in a feedforward control, where the disturbance feedforward the Wind profile measurement used such that the pitch angle of the rotor blades individually adjusted so that when the wind hits the Loads are minimized. In addition, a measurement takes place of remaining charges at the energy recovery plant. These charges are essentially based on errors in the assumptions the feedforward control.

Preferably the measured values are used in a controller, which individual Pitch angle generated in addition to the power plant be adjusted to further reduce the remaining loads.

In In one embodiment, both wind direction and Wind speeds in the distance upstream of the Energy production plant measured to be as informative as possible Wind profile to produce. Wind direction and wind speeds can stored in a vector field.

After all become adjustable components of the power plant such adjusted that the power generation plant with optimal power generation is protected from damage. For suppression of measurement noise, the wind profile readings are calculated using a Filters filtered in the controller. In addition, will to calculate the dead time, which passes until the wind profile the power plant reached, a mean wind speed of the wind profile is determined, with which the wind profile moves towards the power generation plant. In this case, the reaction of the feedforward control delayed to the measured wind profile by the dead time.

In a further preferred implementation In accordance with the invention, an individual pitch or pitch is calculated for each individual rotor blade by means of an iterative method and adjusted at the end of the dead time on the rotor. In addition, for each rotor blade, the expected thrust force and the expected blade root torque are determined on the basis of the preactively measured wind profile. In addition, the expected pitch and / or yaw moment is determined on the basis of the preactive wind profile and the individual rotor blades are adjusted as a precautionary measure.

The The invention will now be more apparent from the accompanying drawings explained.

1 shows a schematic diagram of an energy recovery system according to an embodiment of the invention;

2 shows a control device for the power generation plant according to 1 ,

1 shows a stationary power generation plant 1 with a rotor 2 and a gondola 3 , which has other components of the power plant for converting wind energy into electrical energy. The power generation plant 1 is in a wind field 4 arranged with the help of one at the hub 16 of the rotor 2 arranged praeaktiven wind measuring device 5 with the wind directions a to h and different wind speeds, as is the wind profile 6 shows, is detected. The praeaktiv measured wind conditions and the measured impact and pivoting moments of the rotor blades and the pitch and yaw moments of the nacelle are taken into account in the pitch control and by the corresponding pitch adjustment 14 the rotor blades 11 and 12 set. Thereby the load limit values of the components become 9 considered in the energy recovery plant.

2 shows a control device 7 for the power generation plant 1 under the influence of a spaced upstream of the power plant 1 measured wind field 4 , The stationary power generation plant 1 is in this embodiment of the invention, a wind turbine (WKA), the an IPC controller 18 (Individual pitch control), which adjusts different pitch angles, for example, β ₁ , β ₂ and β ₃ for a three-bladed rotor at the rotor blades. In contrast, the same pitch angle has hitherto been set with standard controllers for wind turbines on all rotor blades.

The IPC controller receives loads of the power generation plant measured as input signals 1 such as blade root bending moments in the direction of impact and / or pivoting, yawing and / or pitching moments on the rotor shaft, etc., and is designed so that it minimizes the measured loads and / or parameters derived therefrom by setting individual pitch angles. However, the IPC controller is so far reactive that it only responds when a load is already measured.

According to the invention will now how 1 and 2 show in advance of the power plant 1 a wind field 4 with a wind measuring device 5 , such as a LIDAR or SODAR system. From this calculated block 13 how the pitch angles β ₁ , β ₂ and β _{3 of} the rotor blades must be adjusted when hitting the wind field in order to minimize the above-mentioned loads or characteristics.

These calculated pitch angles β ₁ , β ₂ and β ₃ are now obtained from the energy recovery plant 1 set. This signal path is preaeactive, ie it responds by the feedforward control 13 before any stresses can be measured reactively. This is the power generation plant 1 adjusted so that at the moment of impact of the measured wind, the loads of the components remain within the desired limits. Through this disturbance variable connection 13 be at the power plant 1 now much smaller loads are measured.

Quite the loads can not be avoided, since the wind field until the impact on the power plant 1 changed and model errors can not be ruled out. The IPC controller 18 now only needs to balance these smaller loads on its signal path. Overall, a significant reduction in load is obtained in comparison to a conventional power generation plant 1 in which the controller 18 without disturbance variable connection 13 has to get along. The two signal paths are at the adder 17 merged.

1

Energy recovery plant

2

rotor

3

gondola

4

Windfeld

5

praeaktive Wind measuring device

6

wind profile

7

control device

9

component the power generation plant

10

sensor

11

rotor blade

12

rotor blade

13

feedforward

14

feathering

16

hub

17

adder

18

IPC controller

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• US 7281891 B2 [0002]
• - EP 1770278 A2 [0003]

Claims (23)

Stationary power generation plant with a control device ( 7 ), a rotor ( 2 ) and a gondola ( 3 ), the other components of the energy recovery plant ( 1 ) for the conversion of wind energy into electrical energy, wherein - the power generation plant ( 1 ) in a wind field ( 4 ) and a plant-mounted preactive wind measuring device ( 5 ) having; - the praeactive wind measuring device ( 5 ) current wind profiles ( 6 ) upstream of the power plant ( 1 ) detected; The control device ( 7 ) a feedforward control ( 13 ), which uses the praeaktive wind profile measurement such that the pitch angle of the rotor blades are individually preset so that when hitting the pre-reactively measured wind field loads are minimized and - remaining loads are measured. Power generation plant according to claim 1, characterized in that the wind measuring device ( 5 ) a preaeactive wind sensor system preferably comprises a LIDAR (light detection and ranging anemometer) system or a SODAR (sound detection and ranging anemometer) system. Power generation plant according to claim 1 or claim 2, characterized in that components ( 9 ) of the energy recovery plant ( 1 ) Sensors ( 10 ), which reduce the loads on the components ( 9 ), and wherein the sensors ( 10 ) with the control device ( 7 ) communicate via signal transfer devices. Power generation plant according to one of the preceding claims, characterized in that the control device ( 7 ) with feedforward control ( 13 ) has a filter with respect to wind speed measurements. Energy production plant according to one of the preceding claims, characterized in that the energy production plant ( 1 ) a computer ( 13 ), which by means of the preactive wind measuring device ( 5 ) determines an average wind speed and wind direction with which the wind profile ( 6 ) to the energy recovery plant ( 1 ) and calculates a dead time, up to the wind profile measured at a distance (FIG. 6 ) the energy recovery plant ( 1 ) reached. Energy production plant according to one of the preceding claims, characterized in that the energy production plant ( 1 ) a device for pitch adjustment ( 14 ) of rotor blades ( 11 . 12 ) and the control device ( 7 ) in response to a wind profile measurement a pitch or pitch of the rotor blades ( 11 . 12 ). Energy production plant according to one of the preceding claims, characterized in that the rotor blades ( 11 . 12 ) from the control device ( 7 ) have predetermined current angle of attack and the feedforward control ( 13 ) depending on the preactive wind profile measurement ( 5 ) additional individual angles of attack for each rotor blade ( 11 . 12 ). Energy production plant according to one of claims 1 to 7, characterized in that the energy production plant ( 1 ) comprises a damping device for damping vibrations in the drive train of the wind energy device and the control device ( 7 ) in response to a wind profile measurement ( 6 ) changes the damping of vibrations in the drive train. Method for controlling an energy production plant ( 1 ), comprising the following method steps: - detecting a wind profile ( 6 ) at a distance upstream of the power generation plant ( 1 ); - calculating a dead time until the arrival of the wind profile ( 4 ) at the power generation plant ( 1 ); - Use of the delayed wind profile in a feedforward control ( 13 ) a control device ( 7 ), with the feedforward control ( 13 ) uses the wind profile measurement such that the pitch angle of the rotor blades ( 11 . 12 ) are individually adjusted so that loads are minimized when the wind hits; - measuring remaining loads on the power plant ( 1 ). Method according to Claim 9, characterized by the further step of using the measured values for the remaining loads in a controller ( 18 ), which generates individual pitch angles, which in addition to the power generation plant ( 1 ) to further reduce the remaining loads. A method according to claim 9 or 10, characterized in that for detecting the wind profile ( 6 ) Wind direction and wind speed are measured. Method according to claim 9, 10 or 11, characterized that the wind profile readings are filtered with a filter, to suppress a measurement noise. Method according to one of claims 9 to 12, characterized in that for calculating the dead time, an average wind speed of a wind profile ( 6 ), with which the wind profile ( 6 ) to the energy recovery plant ( 1 ) moves becomes. Method according to one of claims 9 to 13, characterized in that the reaction of the feedforward ( 13 ) on the measured wind profile ( 6 ) is delayed by the dead time. Method according to one of claims 9 to 14, characterized in that for each rotor blade ( 11 . 12 ) an individual pitch or pitch is calculated by means of an iterative method and set at the end of the dead time. Method according to one of claims 9 to 15, characterized in that for each rotor blade ( 11 . 12 ) the expected thrust force due to the preactively measured wind profile ( 6 ) is determined. Method according to one of claims 9 to 16, characterized in that for each rotor blade ( 11 . 12 ) the expected blade root moment due to the pre-actively measured wind profile ( 6 ) is determined. Method according to one of claims 9 to 17, characterized in that for a nacelle ( 3 ) of the energy recovery plant ( 1 ) due to the proactively measured wind profile ( 6 ) to be expected pitch and / or yaw moment is determined. Method according to one of claims 9 to 18, characterized in that as a wind measuring device ( 5 ) a preaeactive wind sensor system preferably a LIDAR system (light detection and ranging anemometer) or a SODAR system (sound detection and ranging anemometer) is used. Method according to one of claims 9 to 19, characterized in that loads on the components ( 9 ) of the energy recovery plant ( 1 ) by means of sensors ( 10 ) are detected with the control device ( 7 ) communicate via signal transfer devices. Method according to one of claims 9 to 20, characterized in that with respect to an upper limit of the wind speeds, taking into account the load limits of the rotor blades ( 11 . 12 ), the rotor blades ( 11 . 12 ) are turned into a feathered position and the drive train in the nacelle ( 3 ) is stopped and / or decoupled. Method according to one of claims 9 to 21, characterized in that the control device ( 7 ) specifies a current collective angle of attack for the rotor blades and the feedforward control ( 13 ) depending on the preactive current wind profile measurement individual angle of attack for each rotor blade ( 11 . 12 ). Method according to one of claims 9 to 21, characterized in that the feedforward control ( 13 ) preferably calculated a further angle of attack of the rotor blades or pitch, which is added to the existing angles of attack.