Title of Invention

WIND POWER INSTALLATION WITH AN EARLY-WARNING SYSTEM

Abstract

Depending on their respective size and power design wind power installations are relatively expensive capital investment items which are to be protected from ruin, damage or other causes which bring about failure of a wind power installation if the long service life promised for the wind power installation is to be attained. At the same time in relation to wind power installations there is always a wish to operate them at the maximum possible power output so that it is also possible to achieve an energy yield of maximum magnitude. Both aims, namely the long service life on the one hand and the highest possible energy yield on the other hand are in part in diametrally opposite relationship, but ultimately it would admittedly be basically possible for a wind power installation also to be operated partially in the overload range, whereby the energy yield thereof is increased, but at the same time this would also result in a marked curtailment in the service life. If in contrast a wind power installation is operated only in quite low wind speed ranges then the installation is certainly protected better than others, but it is inadequate from the point of view of its energy yield. The object of the invention is to provide measures and possible ways of protecting a wind power installation from damage or circumstances causing failure of a wind power installation, while however at the same time a maximum possible energy yield can also still be achieved. The invention further concerns a wind power installation having a SODAR system which is mounted to the pod of the wind power installation and which detects the region in front of the rotor of the wind power installation.

Full Text

This invention relates to a wind power installation comprising an early-warning system, and a method for controlling one or more wind power installations Depending on their respective size and power design wind power installations are relatively expensive capital investment items, which are to be protected from ruin, damage or other causes which bring about failure of a wind power installation if the long service life promised for the wind power installation is to be attained. At the same time in relation to wind power installations there is always a wish to operate them at the maximum possible power output so that it is also possible to achieve an energy yield of maximum magnitude. Both aims, namely the long service life on the one hand and the highest possibly energy yield on the other hand are in part in diametrically opposite relationship, but ultimately it would admittedly be basically possible for a wind power installation also to be operated partially in the overload range, whereby the energy yield thereof is increased, but at the same time this would also result in a marked curtailment in the service life. If in contrast a wind power installation is operated only in quite low wind speed ranges then the installation is certainly protected better than others, but it is inadequate from the point of view of its energy yield. The object of the present invention is to provide measures and possibly ways of protecting wind power installation from damage or circumstances causing failure of a wind power installation, while however at the same time a maximum possible energy yield can also still be achieved. The invention is based on the realization of not just meaning, as hitherto, the wind conditions at a wind power installation by means of anemometers, but also using those measurement results for wind power installations which in the direction of the wind are arranged behind the first wind power installation so that if necessary, for example when a gust or squall occurs, they can implement a change in their blade setting angle at a moment which is still in good time before the gust or squall hits the wind power installation, and then, when the gust or squall hits the wind power installation, the loading is not so great that it can still give rise to damage. The early-warning system according to the invention is based on fundamentally two in part different approaches which however can also be combined together and which then supplement each other. One possibility involves mounting a so-called SODAR system (see for example http://akulOO.physik.uni-oldenburg.de/Schallausbreitung/sodarl) to the wind power installation itself, preferably to the pod thereof, for example in the front hub region in front of the rotor. Such SODAR systems (Sonic Detection and Ranging) are capable of three-dimensional detection of the wind conditions (online) in a desired direction (in the direction of the wind) in front of the wind power installation. If therefore a SODAR system is mounted to a pod of the wind power installation and directed towards the region in front of the rotor of the wind power installation, there is no need for any subsequent adjustment (as the SODAR system is always oriented with the pod in the direction of the main wind direction) and can observe the region in front of the rotor of the wind power installation to ascertain whether gusts or squalls occur. Admittedly the^SODARr systems are previously basically known, but hitherto they have only been stationarily constructed or are transported in the form of mobile installations on a trailer and then only serve for one-off measurement of a wind profile in a given region. In accordance with the invention such SODAR systems are left at the wind power installation and are not just set up stationarily once, so that when a gust or squall approaches, which could result in unwanted overloading of the wind power installation, that is detected in good time and the rotor blades are suitably adjusted at a time which is still prior to the gust or squall hitting the wind power installation so that the loading that the gust or squall applies to the wind power installation is markedly less than with unadjusted rotor blades. If the SODAR system is mounted to a wind power installation (or a plurality thereof) which is erected in a wind park and if the wind power installation is erected in the edge region of the wind park, which the approaching wind hits first, the data measured by the SODAR system can not only be processed in the wind power installation which carries the SODAR system, but also by all further wind power installations which, in the direction of the wind, are behind the wind power installation equipped with the SODAR system, so that there too the gust or squall passing therethrough, or other detrimental wind conditions, cannot cause any damage if the wind power installations suitably set the rotor blades into the wind and thus they are unassailable for a squall or gust or other disadvantageous wind conditions. In the case of wind parks however there is also a possible alternative form of an early-warning system insofar as the previous anemometers and loading measuring devices which are mounted to a wind power installation can be used not only to provide data which are important for the wind power installation which carries the anemometer or the loading measuring device, but are also put to use for the wind direction behind the wind power installation with the anemometer. If for example the anemometer measures very high wind strengths then corresponding items of information can be delivered to the further installations which in the direction of the wind are behind the wind power installation involved, and those further installations can then also so adjust the rotor blades in good time before the occurrence of the unwanted wind conditions which involve a dangerous loading, or can so take other steps, for example completely shut down installations, that the loadings caused by the detrimental wind conditions and thus any damage which may possibly occur are as slight as possible and are preferably entirely avoided. Setting of the rotor blades into the wind usually means that the surface area of the rotor blades, which is exposed to the wind, decreases, and under some circumstances that can also result in a reduction in the electrical power output. That disadvantage is accepted however if, with the avoidance of overloads, it is possible to avoid the damage which they entail, and ultimately even just a few overload situations can markedly reduce the service life of the entire installation so that a temporarily reduced level of power output is scarcely crucial if that is considered for the overall service life of the wind power installation. The early-warning system according to the invention in which data (wind and loading data) which are measured at one wind power installation can also be used for other wind power installations presupposes a communications network between the wind power installations of a wind park, in which respect data transmission can be effected wirelessly or also by a hard-wired system and network technoloaies which are alreadv known can be used for the transmission itselfT In this case data communication can be from one installation to another and also by way of a central control. The central control can in turn pass the items of information relating to the wind conditions which are measured at the installation, to all or selected wind power installations (for example those in the 'wind shadow1 of a given installation) of a wind park and/or can in turn provide the required control signals and communicate them to the respective wind power installations. It will be appreciated that it is also possible to envisage a combination of SODAR and anemometer measuring detection procedures so that communication can be implemented on the one hand from one installation to another and on the other hand by way of a central control so that there is information redundancy which for example permits error correction. Plausibility checking can also be effected for example in such a way that the control instruction from the central control for the wind power installation can be checked on the basis of the wind speed or wind direction data communicated from one installation to another and is implemented only when plausibility is established. It will be appreciated on the other hand that it is also possible for each installation to effect ^suitable control in its own control device on the basis of the data communicareg Deuvyeen the installations and a central control arrangement performs a corresponding monitoring procedure. As the distance between the individual wind power installations of a wind park is invariable, it is possible; on uie basis of the known wind speed, when disadvantageous wind conditions occur, to (pre-)calculate quite reliably when the correspondingly detrimental wind conditions, for example the gust or squall, reach which installation. Accordingly for example it is possible to calculate a wind speed-dependent lead time that the installation requires in order to implement the required adjustment (angle of attack of the rotor blades with respect to the wind). Alternatively or additionally it is possible to introduce a fixed component for the lead time. By virtue of the distances between the individual wind power installations and the wind speeds the resulting pre-warning times should usually suffice to change the blade angles in good time (the pitch speed is between about 4 and 8°/second). As mentioned, the operation of ascertaining the items of information relating to the wind conditions which are measured at a wind power installation can basically be effected at all wind power installations of a wind park. An alternative can be information communication which is dependent on wind direction, in which case it would then be possible to provide a spread angle in order to communicate the information at least to the installations which are directly beside the path of the wind. That angle can again be fixed or it can be selected in dependence on fluctuations in the direction of the wind. It will be appreciated that, in the course of information communication, besides the pure wind speed and wind direction data, it is also possible to communicate further data such as identifications of transmitter and target wind power installations, error correction codes or similar items of information. Giving particular consideration to the direction of the wind appears appropriate from the aspect that, with a substantially constant wind direction, local gusts always still occur, which (can) reach only a part of the wind power installations so that, from the point of view of optimising yield, only the wind power installations which are actually in the way of such a gust also have to be suitably controlled so that the loading which occurs there turns out to be as low as possible. A wind power installation may comprise an acoustic measurement system for measuring the wind speed and wind direction in the region of the wind power installation. The measured data is processed by a control device for controlling the adjustment of the angle of attack of the rotor blades of the wind power installation such that the angle of attack is adjusted as soon as a wind condition endangering the wind power installation is measured. Accordingly the present invention provides a wind power installation comprising a tower, a pod on top of the tower, a rotor and an early-warning system, characterized in that said early-system is mounted on the pod and comprises an acoustic system for detecting the wind speed in the region in front of the rotor. Accordingly the present invention also provides an early-warning system for protecting wind power installations in a wind park having a plurality of wind power installations, comprising measurement means for measuring the wind conditions in the region of a first of said plurality of wind power installations, a control means for processing the measured data and for controlling the first and/or another wind power installation in the proximity of the first wind power installation, wherein said control means controls the adjustment of the angle of attack of the rotor blades of said first or further wind power installation with respect to the wind, and wherein said control means controls the adjustment of the angle of attack as soon as wind conditions are measured, which endanger said wind power installation. Figure 1 shows by way of example a wind park arrangement with a plurality of wind power installations 1 which are each, connected to a central control 2. In this case the central control can suitably process measured data from individual installations and also provide suitable control signals for individual installations. Figure 2 shows by way of example a typical situation of use. In this case the wind 3 flows to a given installation 4 first, which in turn passes the measured data to a central control or in some other manner (non-central control) to other installations. It is to be expected that the wind which impinges against the installation will also hit the installations which are arranged in the immediate wind shadow of the installation (narrow hatching). It is however quite possible for the spread angle also to be made wider (wider hatching) in order thereby to define a wider 'wind shadow' so that, at all installations which partly or completely fall into the hatched region, the measurement results of the first installation can therefore also be used to control the further installations in the wind shadow of the first installation, in such a way that damage to the further installations does not occur and they are therefore also protected by virtue of evaluation of the measurement results of the first installation. As already described, instead of a central control 2, it is also possible to use another control concept. Thus for example that concept can also be such that there are data (radio) connections between adjacent installations or between wind power installations of a given region and in that way measurement data can also be exchanged wirelessly and without a central control between wind power installations. It is also possible that, when a given wind situation arises, for example in the case of gusts, it is not only the installation that is specifically involved which is adjusted, but all installations in the immediate proximity of that installation or installations, which are in a given geographical relationship with the affected installation. That can be for example as shown in Figure 2 also the wind power installations 6 which are to the right and to the left of the affected installation in the direction of the wind. If the first installation 4 as shown in Figure 2 is equipped with a SODAR, then, when the gust hits the first wind power installation, that gust can already be measured and suitable precautions can also be taken at the first wind oower installation so as to avoid any damage. WE CLAIM: 1. A wind power installation comprising a tower, a pod on top of the tower, a rotor and an early-warning system, characterized in that said early-warning system is comprises an acoustic system for detecting the wind speed in the region in front of the rotor, the said early-warning system is mounted on the pod. 2. The wind power installation according to claim 1 wherein said acoustic system is mounted in the region of a rotor hub of the wind power installation, preferably in front of the plane of the rotor of the wind power installation. 3. The wind power installation according to anyone of the claims 1 and 2, wherein said wind power installation comprises a control means for altering the angle of attack of the rotor blades when undesirable wind speeds occur. 4. The wind power installation according to anyone of the claims 1 to 3, wherein the early-warning system comprises a transmitting/receiving device for transmitting/receiving wind speed and/or wind direction information to/from at least one further wind power installation within a wind park. 5. The wind power installation according to anyone of the claims 1 to 4, wherein said acoustic system for detecting the wind speed is an ultrasonic waves acoustic system. 6. The wind power installation according to claim 5, wherein the acoustic system is an acoustic system for three dimensionally detecting the wind speed. 7. An early-warning system for protecting wind power installations within a wind park having a plurality of wind power installations, comprising an acoustic system for detecting the wind speed in the region of a first of said plurality of wind power installations, and a transmission device for transmitting the detected wind speed to wind power installations within the wind park. 8. A method for controlling one or more wind power installations, comprising the steps of detecting the speed of the wind in front of a first of said wind power installations before the wind has reached said first of said wind power installations, and controlling the adjustment of the angle of attack of the rotor blades of said first of said wind power installations in dependence on the detected wind speed or wind direction. 9. The method according to one of the claims 8, comprising the step of: detecting the wind speed by an acoustic system which is arranged on one or more wind power installations of a group of wind power installations. 10. The method according to one of the claims 8 to 9, comprising the step of: controlling each individual wind power installation before the wind has reached the wind power installation with regard to the detected wind speed or wind direction. 11. The method according to one of the claims 8 to 10, wherein the adjustment of the angle of attack of the rotor blades of a wind power installation is determined by a control device in the wind power installation or is determined by a central control. 12. The method according to one of the claims 8 to 11, comprising the step of: communicating the information in respect of the wind conditions between wind power installations either wired or wirelessly. 13. The method according to any one of the claims 9 to 12, wherein the step of detecting the speed of the wind in front of a first of said wind power installations is performed by an acoustic system for determining the wind speed, comprising the steps of: determining the wind speed of a first wind power installation which is first exposed to the incoming wind, transmitting the determined wind speed to at least one second wind power installation which is arranged behind the first wind power installation such that the second wind power installation is arranged in the wind shadow of the first wind power installation, and controlling the second wind power installation according to the determined wind speed of the acoustic system which is mounted on the first wind power installation.

Documents:

0184-chenp-2004 abstract-duplicate.pdf

0184-chenp-2004 claims-duplicate.pdf

0184-chenp-2004 description (complete)-duplicate.pdf

0184-chenp-2004 drawings-duplicate.pdf

184-chenp-2004-abstract.pdf

184-chenp-2004-claims.pdf

184-chenp-2004-correspondnece-others.pdf

184-chenp-2004-correspondnece-po.pdf

184-chenp-2004-description(complete).pdf

184-chenp-2004-drawings.pdf

184-chenp-2004-form 1.pdf

184-chenp-2004-form 26.pdf

184-chenp-2004-form 3.pdf

184-chenp-2004-form 5.pdf

184-chenp-2004-form19.pdf

184-chenp-2004-pct.pdf