Patent Application
20090110539
A wind farm and a method for controlling a wind farm are disclosed herein.
In the past, wind turbines are experiencing an increasing demand in sales. Therefore, more and more wind turbines are also planned and erected at sites with higher icing probability during the year. For example, such sites may be located in cold and hash climate like northern Europe, off-shore locations or alpine areas. These conditions lead to an increased probability of icing, i.e., ice accretion. Particularly, icing at the rotor blades of the turbines results in reduced energy output. This is based on increased mass loads on the wind turbine as well as in deterioration of the aerodynamic properties of the wind turbine. Further, regulations to shut down the wind turbine in the event ice-throw may occur which further deteriorates the energy output. Typically, shut down regulations are stricter for wind turbines located in populated areas and/or near public roads.
In view of the above, a windfarm is provided, the wind farm including a plurality of wind turbines, an ice detection sensor adapted to detect an icing condition of at least one of the plurality of wind turbines, and a main controller connected to the ice detection sensor and to at least two of the wind turbines, wherein the main controller is adapted to control the operation of the at least two wind turbines based on an icing condition detected by the ice detection sensor.
Further aspects, advantages and features are apparent from the dependent claims, the description and the accompanying drawings.
According to an embodiment, a wind park is provided, the wind park including at least two wind power plants connected to an icing detection unit, wherein the at least two wind power plants share the icing detection unit and wherein the operation of the at least two wind power plants is controllable on the basis of an icing status of at least one of said wind power plants detected by the shared icing detection unit.
According to a further embodiment, a method for controlling the operation of wind turbines in a windfarm is provided, the method comprising detecting an icing condition of at least one wind turbine comprised in the wind farm, and controlling the operation of at least two wind turbines comprised in the wind farm on the basis of the detected icing condition of the at least one wind turbine.
A full and enabling disclosure of embodiments, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures wherein:
Reference will now be made in detail to the various embodiments of the invention, one or more examples of which are illustrated in the figures. Each example is provided by way of explanation of the invention, and is not meant as a limitation. For example, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that such modifications and variations are included herewith.
Due to the above-described configuration, only a single ice detection sensor 200 is required to control the complete windfarm 1000. In other words, at least two wind turbines or wind power plants of wind park 1000 share an icing detection unit and can be collectively controlled on the basis of an icing status detected by the shared icing detection unit. Therefore, it is not longer necessary to equip each individual wind turbine 100 within windfarm 1000 with its own ice detection sensor. As a result, the costs of each turbine can be considerably reduced. Furthermore, it is not longer necessary to monitor each individual wind turbine. For example, the icing status of only one or two wind turbines 100 may be monitored but all the wind turbines comprised in wind park 1000 may be collectively controlled based on the monitoring result. For example, all the turbines in windfarm 1000 may be collectively shut down when icing is detected. Thus, it can be avoided that only some turbines are shut down while others still run as it may happen due to tolerances in ice detection if each turbine is equipped with its own ice detection sensor.
In the above example, only one ice detection sensor is utilized for the control of all the wind turbines 100 in the windfarm 1000. However, it will be understood by those skilled in the art that also one or more redundant sensors may be provided as a backup system or as a system for gathering higher statistical accuracy. Furthermore, in larger windfarms it may be expedient to divide the wind turbines in two or more sub groups, each of those subgroups being equipped with its own ice detection sensor and main controller. In this event, the signals of the ice detection sensor of the sub group can be distributed to and processed by all wind turbines included in the subgroup. In particular, the configuration will be still such that two or more wind turbines share one ice detection unit.
In the embodiment shown in
Furthermore, windfarm 1000 includes a web cam 400 for detecting an ice-free condition of at least one wind turbine within the windfarm. In other words, web cam 400 is a sensor for detecting a non-icing or ice-free condition. Like ice detection unit 200, also web cam 400 is connected to main controller 300. For example, wind turbines 100 may have been previously shut down by main controller 300 due to an icing condition detected by ice detection unit 200. If web cam 400 now detects that the rotor blades 8 are again ice-free, it signals to main controller 300 that operation may be resumed. Then, main controller 300 initiates a start-up sequence for wind turbines 100, 110 to bring them back up online. According to another embodiment, the windfarm 1000 is re-activated manually, typically via remote control, on the basis of the web cam pictures. Likewise also for the opposite case, namely detecting an ice-free condition, the measurement results of a single sensor may be shared by several wind turbines to coordinate their control collectively.
It will be understood by those skilled in the art that in any of the above-described or other embodiments, the main controller 300 may be adapted to control each wind turbine 100, 110 and/or each wind turbine controller 120 individually. In embodiments, main controller 300 may be connected to the turbine controllers 120 at each individual wind turbine 100, 110, wherein the main controller 300 is adapted to control and/or instruct the turbine controllers 120. For example, main controller 300 may be adapted to shut down two or more wind turbines 100, 110 on the basis of an icing condition detected by the ice detection sensor 200. In particular, main controller 300 may be adapted to shut down all the wind turbines comprised in the windfarm or in a subgroup of the windfarm on the basis of the detected icing condition. On the other hand, main controller 300 may also be adapted to start up two or more wind turbines 100, 110 on the basis of an icing condition detected by the ice detection sensor 200 or an additional sensor 400 for detecting an ice-free condition. Also in this embodiment, main controller 300 may be adapted to start up all the wind turbines comprised in the windfarm or a subgroup of the windfarm on the basis of the detected ice-free condition.
In one embodiment, all the wind turbines comprised in the windfarm are simultaneously shut down on the basis of the detected icing condition. Likewise, all the wind turbines comprised in the windfarm may simultaneously restarted on the basis of the detected icing condition. In particular, the wind turbines may be brought back up online when an ice-free condition is detected by a web cam provided as a sensor for an ice-free condition.
This written description uses examples to disclose embodiments, including the best mode, and also to enable any person skilled in the art to make and use such embodiments. While various specific embodiments have been described, those skilled in the art will recognize other embodiments can be practiced with modification within the spirit and scope of the claims. Especially, mutually non-exclusive features of the embodiments described above may be combined with each other. The patentable scope is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
