Wind turbine

The Invention relates to a wind power plant according to the preamble of claim 1.

Such Wind turbines are to the prior art. For example, shows the German reference book "Wind Turbines" by Erich Hau, Springer-Verlag, 2nd Ed., 1996, pages 52, 175, 222-242, 269, 320 such Wind turbines. These known wind turbines can be using a rotor speed Rotorblatteinstellwinkelregelung and regulate the power output. In addition, serves the well-known Rotorblatteinstellwinkelregelung protection against overspeed the rotor at high wind speeds or during a power failure, in which the generator torque suddenly invisible. In both cases concern is the wind turbine against destruction by too high rotating protect rotor.

there There are essentially two ways of using the blade adjustment a reduction in the rotor speed to bring about: on the one hand can be the Blade pitch in the direction of smaller aerodynamic angle reduce, thereby reducing the power consumption of the rotor. On the other hand, it is possible to larger adjustment angles critical by adjusting the Rotorblatteinstellwinkels aerodynamic angle, the so-called stable state to to accomplish. The latter option offers the advantage of adjustment shorter path, but brings the Disadvantage that the stall (Barn) with heavy loads for is the rotor and the entire wind power plant connected. Both settings However, in common is that they only have an average, all the Wind turbine acting wind speed or a certain consider limiting the rotor speed as a start signal for the blade angle setting.

A known wind power plant is in the <patcit><text>DE 30 00 678 A1</text></patcit> disclosed. According to this Publication is the wind in the rotor plane of wind turbines measured by means of pressure probes on the surface of the blades near the profile nose attached. In this publication the measured as described above is used, among other things, the rotor plane a wind turbine to pivot until the measurements for a Rotor position of 90 ° and of 270 ° equal are.

The aforementioned options take account of the prior art not that it particularly with a large rotor diameter to a uneven distribution the wind conditions on the rotor surface can come. This in turn has different loads on individual rotor blades, and asymmetric loads on the drive train of the wind turbine, that is, the hub, the drive shaft and the respective bearings. Such differences of asymmetric loads occur but not only until a certain rotor speed or a certain wind speed on, but constantly find also while the normal rated wind speed instead of the wind turbine. The previously known from the prior art pitch control can therefore not to wind speed fluctuations and related Load variations in the rotor area react as in the known Plants takes place a uniform, synchronous adjustment of the rotor blades.

at newer plants (see especially pages 238 of the above reference book) While on the one hand an individual electrical adjustment of each individual Rotor blade has been proposed; but also finds this proposal instead of assuming an average wind speed, acting on the wind turbine. This and further Assuming that the wind velocity increases with height, then a fixed, circulating cyclic correction of rotor blade pitch angle proposed to the changing loads on the increase in wind speed with the height at least partially to compensate. Also in this Rotorblatteinstelltechnik it is disadvantageous that the pitch of the rotor blades fixed is predetermined and therefore not on local and temporary changes the wind speed in a partial area of ​​the rotor react can. Also with this proposal, therefore, takes place at local peaks in wind speed asymmetric and thus lebensdauerverkürzende load the components instead of the wind turbine.

task the invention is therefore to avoid the above-mentioned problems and to provide a wind power plant is available, in which the loads are reduced, due to local and transient spikes in the wind speed in partial areas of the rotor surface may occur.

These Object is through a Wind power installation according to claim 1 dissolved.

By The wind power plant according to the invention is makes it possible with the help of the adjustment for individual adjustment a rotor blade, the wind turbine on current, only one Part of the wind turbine locally applied stresses of the measuring means determines, with &lt;?page 3?&gt;Using the control means vote. Thus, it is advantageously achieved that local peaks of the load blades, the hub, final drive and the bearings used are avoided. This in turn has the consequence that the service life of the wind turbine is increased as asymmetric and the life shortening stresses are parts of the wind turbine is largely avoided.

Furthermore allows there the wind power plant according to the invention the current distribution of wind speeds on the rotor face perfectly exploit and therefore an increased power yield contribute the wind power plant, since all blades always having a desired and thus optimum blade angle are driven and therefore the efficiency each rotor blade towards the efficiency of the wind turbines from the prior art increases.

Especially preferably it is that the position of the rotor blade or blades continuously the current strain of the wind turbine is adjusted. In this way can to ensure that the wind turbine continuously optimum operating range is driven while before load peaks, triggered by locally available in the rotor field peaks in the wind speed, protected is.

at a preferred embodiment, the invention determine the measuring means for determining the local stress of a rotor blade on the rotor blade prevailing wind speed. To this end , the measuring means preferably to an attached on the rotor blade anemometer. Thereby, that this Anemometer is arranged directly on the rotor blade, a very precise Controlling the angular position of the rotor blade in response to a increased or lower wind speed possible. This is because the measurement the wind speed directly to the place where even an adjustment the wind power installation takes place, namely directly on to be adjusted Rotor blade, is a fast and accurate adjustment of the blade angular position to local changes wind speed possible.

A Another preferred embodiment is characterized is characterized in that the measuring means a predominant part in a portion of the rotor frame mechanical Last determine. In this embodiment, is the direct determination of a section of the Rotor applied mechanical stress to the control means a precise given information that will help them, taking account the predetermined geometry, load and / or material data a desired position at least can determine an adjustable rotor blade.

Especially advantageously in this embodiment, is when the measuring means a prevailing in the adjustable rotor blade mechanical load determine. For while the load is determined directly in the rotor blade, can similarly as in the above direct determination of the wind speed on the rotor blade, a very precise Information about the Wind force profile over the rotor surface be won. With such detailed information, the control means then capable of a particularly precise reaction of the adjustment device to control, so that a existing load peak in a partial section of the rotor very quickly can be degraded.

A another embodiment of the invention with a rotor hub for receiving the rotor blades includes measuring means on that measure a known mechanical load in the rotor hub. Also in this embodiment let yourself a quick adjustment of the rotor blades to the changed load situation make. The same applies to embodiments with an axle journal for supporting the rotor, wherein the measuring means identify a dominant in the journal load and at a Wind power installation having a drive shaft, the rotor and the generator directly or via a gear to each other, wherein the measuring means one in the drive shaft or in the bearings of the drive shaft or Calculate the journal prevailing load. All of the above embodiments enable an accurate determination of local load conditions in the rotor area and Thus, an accurate control of the adjustment means of the Control means. It is particularly preferred that the measuring means having for measuring the mechanical load stretch marks that attached to the respective loaded parts of the wind turbine are. This means, the stretch marks on the rotor blade in the interior of the rotor blade on the rotor hub or in the interior of the rotor hub, or on the axle journal inside of the axle journal, on the drive shaft or in the interior of the drive shaft or on the bearings mounted. In all the aforementioned mounting variants is a simple determination of the existing mechanical stress and thus the present invention individual Adjustment of the rotor blade is possible.

A Another preferred embodiment of the Invention comprises measuring means on which a prevailing on the rotor blade to be adjusted angle of attack Calculate the wind. Thereby, it is advantageously possible also the wind direction of the oncoming Wind relative to determine the to be adjusted rotor blade. With Using this measured value, the Control means also on an existing in a partial area of ​​the rotor Windrichtungsände&lt;?page 4?&gt;tion react.

Especially in conjunction with the above-mentioned Lastmeßmitteln obtain a control means very accurate picture of the current wind conditions on the Rotor area: by the load measuring means can the control means considered an absolutely existing load and by the measuring means for determining the angle of incidence can about addition also - under consideration the actual Rotor blade position - a accurate determination of the size of the adjusted angle be made. An exact adaptation rapidly in response to changing wind conditions is thus defined by the combined use of Anströmwinkelmessung and load measurement in the rotor blades advantageously ensured. It is particularly preferred that Measuring the angle of incidence make by attached to the rotor blade wind vane.

A Another preferred embodiment of the Invention is characterized in that a part section of a rotor blade asynchronously to at least one further adjustable partial section of a is another rotor blade adjustment. Thus can be especially with large rotor diameters of reduce design effort by preferably the outer Part of the rotor blade, since the power generation of the rotor largely on the outer blade portion concentrated, adjustable design becomes.

at an advantageous embodiment, the invention can be the for a certain momentary stress desired position of the or Rotor blades with the control means connected input means pretend. In this manner and way before the wind power plant according to the invention Place after installation of possibly unforeseen wind conditions or after a repair to changed thicknesses or amended adapted airfoils will.

As Especially advantageous has proven to the actual value of the rotor blade angle position tap off of an adjusting gear, which together with a Adjusting the adjustment forms. It is particularly advantageous if the control means controls the adjustment of the rotor blade virtually simultaneously with the measurement of values ​​of the stretch marks, the anemometer or wind vane by comparison with the actual value make the adjusting means of the adjustment. By such instantaneous response to load changes in the area of ​​the rotor blades an effective reduction of harmful Loads or weight on one side of the rotor ensures.

On advantageous method for adjusting a wind turbine on only in a Iokalen Part of the wind turbine prevailing instantaneous Stresses is characterized in that measurement means of the instantaneous load a part of the wind power installation is detected, and by control means one for the momentary stress desired Position of at least one of the rotor blades is determined and that accordingly adjusted the rotor blade using the adjusting accordingly is, wherein the adjusting device and the measuring means to the control means are connected by means of connecting means. This simple Process can be an effective increase achieving of life and efficiency of the wind turbine according to the invention.

More advantageous embodiments are in the dependent claims described.

A embodiment the invention will be with reference to the accompanying drawings described, in which:

<figref idrefs="S14">1</figref> on partial section of a wind power plant according to the invention is;

<figref idrefs="S15">2</figref> a Frontal view of a wind power plant is erfindungsgemäßeq; and

<figref idrefs="S16">3</figref> on Block diagram showing the control of the adjustable rotor blade in a preferred embodiment of the invention.

The <figref idrefs="S14">1</figref> shows a wind power plant <figref>1</figref> in a partial section. The Wind turbine <figref>1</figref> rests on a (only partially shown) tower <figref>2</figref>, At the top of the tower<figref>2</figref> a housing <figref>4</figref> on Tower mounted. Below the housing<figref>4</figref> is a attached to the tower maintenance platform <figref>6</figref>, The housing<figref>4</figref> has in its (in the drawing enclosed, shown on the right) a rear portion (not shown) and a generator shown in dashed lines control unit <figref>8th</figref> on. The generator is located behind a bulge <figref>10</figref> the housing <figref>4</figref> and is over fasteners <figref>12</figref> with its (not shown) runner on the rotor hub <figref>14</figref> flanged. The rotor hub<figref>14</figref> and the (only partially shown) Blades <figref>16</figref> together the rotor <figref>18</figref>, The rotor<figref>18</figref> with its rotor hub <figref>14</figref> via bearings <figref>20</figref> on a journal <figref>22</figref> stored. The journal<figref>22</figref> protrudes by the rotor hub <figref>14</figref> provided opening <figref>24</figref> by the rotor hub <figref>14</figref> therethrough. The journal<figref>22</figref> is tower side within the housing <figref>4</figref> With the tower <figref>2</figref> connected. From the substantially vertically drawn up tower <figref>2</figref> extends the journal <figref>22</figref> opposite the Horizontal slightly tilted upward from. The journal<figref>22</figref> is with the (not shown) of the generator stator &lt;?page 5?&gt;connected and projects through the rotor of the generator and through the opening <figref>24</figref> of the rotor hub <figref>14</figref> therethrough and is after its exit from the opening <figref>24</figref> on the of the tower <figref>2</figref> side facing away from the rotor <figref>18</figref> from a closing piece <figref>26</figref> completed.

In turn perpendicular to the axis of the journal <figref>22</figref> extend the rotor blades <figref>16</figref> outward. there contact the rotor blades <figref>16</figref> through openings <figref>28</figref> in the front housing <figref>30</figref> therethrough. The front housing <figref>30</figref> is movable with respect to the fixed to the tower <figref>2</figref> connected housing <figref>4</figref> tight with the hub <figref>14</figref> connected.

The blades <figref>16</figref> are a Flange connection with the rotor hub <figref>14</figref> rotatable about its longitudinal axis connected. A variable displacement motor<figref>34</figref> is attached to the flange <figref>32</figref> appropriate and moved on an adjustment <figref>36</figref> the rotor blade <figref>16</figref>, The adjustment motor<figref>34</figref> and the adjusting mechanism <figref>36</figref> are electric (in <figref idrefs="S16">3</figref> illustrated) compounds <figref>50</figref> or. <figref>46</figref> with the control device <figref>8th</figref> connected. The front housing <figref>30</figref> encloses the rotor hub <figref>14</figref> with the To store <figref>20</figref>, The flange <figref>32</figref>, The servomotor <figref>34</figref> and the adjusting <figref>36</figref> weathertight. The front housing<figref>30</figref> has a cross-sectionally substantially semi-spherical shape.

At the journal <figref>22</figref> there are stretch marks <figref>38</figref>, At the rotor hub <figref>14</figref> there are stretch marks <figref>40</figref>, The stretch marks <figref>38</figref> are connected via an electrical connection 4<figref>2</figref> with the control device <figref>8th</figref> connected. The stretch marks <figref>40</figref> are a (in <figref idrefs="S16">3</figref> illustrated) electrical connection <figref>48</figref> with the control device <figref>8th</figref> connected.

The <figref idrefs="S15">2</figref> shows Parts of the wind turbine <figref>1</figref> of the <figref idrefs="S14">1</figref> of the Rotor side seen. <figref idrefs="S15">2</figref> shows tower <figref>2</figref> With the rotor hub attached to its tip <figref>14</figref>, Of the rotor hub <figref>14</figref> go star-shaped three rotor blades <figref>16</figref> out. The rotor blades <figref>16</figref> are the flange <figref>32</figref> with the rotor hub <figref>14</figref> connected. For clarity of illustration, the front housing <figref>30</figref>. of adjusting <figref>34</figref>, The adjusting mechanism <figref>36</figref>. the journal <figref>22</figref>, the opening <figref>24</figref> and the final piece <figref>26</figref> out of the <figref idrefs="S14">1</figref> not shown.

At the rotor blades <figref>16</figref> are Wind Vane <figref>44</figref> for measuring the angle of incidence of the rotor blades on the <figref>16</figref> aptly Wind mounted. The wind vane<figref>44</figref> are a (in <figref idrefs="S16">3</figref> illustrated) electrical connection <figref>52</figref> With the control unit <figref>8th</figref> (<figref idrefs="S14">1</figref>) connected.

Based on of the block diagram of <figref idrefs="S16">3</figref> is in following describes the operation of the wind turbine according to the invention.

During the Operation of the wind turbine <figref>1</figref> rotating the rotor <figref>18</figref> around the axis of the journal <figref>22</figref>, Here, the rotor blades<figref>16</figref> a particular, with the aid of the control unit <figref>8th</figref>. the adjusting motor <figref>34</figref> and the adjusting mechanism <figref>36</figref> predetermined Angle position relative to the plane in which the rotor blades <figref>16</figref> rotate, the rotor plane. The instantaneous angle α_currently of the blades <figref>16</figref> relative to the Rotor plane is supplied to the control unit <figref>8th</figref> from the adjusting <figref>16</figref> as the actual value of the instantaneous position of the rotor blade <figref>16</figref> about an electrical connection <figref>46</figref> transmitted. Simultaneously, the control unit receives<figref>8th</figref> from the stretch marks <figref>38</figref>That on the journal <figref>22</figref> secured are measured values ​​on the current load of the journal <figref>22</figref> via line <figref>42</figref> ( "Load signal journal" of <figref idrefs="S16">3</figref>). Also using simultaneously with the transmission of the instantaneous position angle of the rotor blades <figref>16</figref> The ECU receives <figref>8th</figref> from the stretch marks <figref>40</figref> on the rotor hub on the management <figref>48</figref> Readings on the current load of the rotor hub <figref>14</figref> ( "Load signal hub" of <figref idrefs="S16">3</figref>). provides the control unit <figref>8th</figref> With Help the stretch marks <figref>38</figref>. <figref>40</figref> a unilateral Load firmly of the rotor, so are the controller <figref>8th</figref> considering the instantaneous position angle α_currently the rotor blades <figref>36</figref> and the current, from the wind vane <figref>44</figref> determined angle of attack β a signal α_new about the management <figref>50</figref> to the adjusting <figref>34</figref> to adjust of the corresponding blade <figref>16</figref> α by the difference_new - α_currently Thereby that this control unit <figref>8th</figref> continuous the measured values of stretch marks <figref>38</figref> and <figref>40</figref> receives and quasi instantaneously considering the also constantly on the management <figref>52</figref> to the control unit <figref>8th</figref> transmitted Angle of attack β the operation command to the adjusting <figref>34</figref> for setting a new angle the rotor blades <figref>16</figref> publishes, found on-line with a change the load conditions in the area of ​​the rotor to adapt the position of the rotor blades <figref>16</figref> instead of and thus an on-line compensation of unbalanced loads of rotor <figref>18</figref>,

alternative to the measurement of the instantaneous load on the wind turbine by stretch marks on the rotor hub and axle pin is also a Load measurement directly on the rotor blades by corresponding stretch marks conceivable.

In conclusion noted that the different signals (ie "load signal hub" 40, "Last Signal journals" 38, "Current angle α_currently"46 and" angle of attack β "53) for determining the ideal blade angle are used, either together or may alternatively be used.