Method of operating at least one wind turbine, and device therefor

Abstract

A method of operating at least one wind turbine including: receiving a first signal which is indicative of a level of a remuneration for electrical energy, which is fed currently and/or in the future into a grid to which the wind turbine is connected, producing a control signal dependent on the first signal, and controlling the wind turbine with the control signal for generating power of the wind turbine, that is dependent on the control signal. A wind turbine and a central control for carrying out such a method and a system comprising a central control and a plurality of wind turbines.

Claims

1. A method of operating a wind turbine, comprising: receiving a first signal indicative of a remuneration of electrical energy currently fed and/or to be fed into a grid, wherein the wind turbine is coupled to the grid; and generating a control signal based on the first signal; and controlling the wind turbine using the control signal for generating power based on the control signal, wherein controlling the wind turbine includes: storing a schedule specifying a plurality of different operating points of the wind turbine for a plurality of different time periods, respectively, the plurality of different time periods being in a pre-defined period of time, and each operating point of the plurality of different operating points representing a setting of the wind turbine that is dependent on wind speed; and operating the wind turbine per the plurality of different operating points specified by the schedule, wherein an operating point of the wind turbine changes in response to the first signal changing by more than a pre-defined second threshold value, and the operating point of the wind turbine does not change in response to the first signal changing by less than the pre-defined second threshold value.

2. The method as set forth in claim 1, comprising: receiving at least one second signal indicative of at least one factor for determining current electricity generation costs of the wind turbine; and producing the control signal based on the first signal and the at least one second signal.

3. The method as set forth in claim 2, comprising: setting operating points of at least one operating characteristic of the wind turbine; and refraining from using at least one region of the at least one operating characteristic to prevent operating points in the at least one region from being set, wherein refraining from using the at least one region is performed based on the first signal or the first signal and the at least one second signal.

4. The method as set forth in claim 2, comprising: receiving, by a second controller different than a central controller, the first signal and the at least one second signal; and generating, by the central controller, wind turbine control signals for a plurality of wind turbines, respectively, and transmitting the wind turbine control signals to the plurality of wind turbines, respectively, to respectively control the plurality of wind turbines with the wind turbine control signals such that the plurality of wind turbines generate power dependent on the respective wind turbine control signals.

5. The method as set forth in claim 4, comprising: generating, by the wind turbine, the at least one second signal and transmitting, from the wind turbine to the central controller, the at least one second signal; or transmitting, from the wind turbine to the central controller, the at least one factor for determining the current electricity generation costs of the wind turbine, and generating, by the central controller, the at least one second signal for the wind turbine based on the at least one factor.

6. The method as set forth in claim 4, wherein a first wind turbine of the plurality of wind turbines having present lower electricity generation costs than a second wind turbine of the plurality of wind turbines generates a higher power output than the second wind turbine.

7. The method as set forth in claim 2, comprising: receiving, by the wind turbine, the first signal; generating, by a controller of the wind turbine, the at least one second signal; and generating, by the wind turbine, internal control signals for use within the wind turbine and to control operation of the wind turbine such that the wind turbine produces a power output dependent on the control signal.

8. The method as set forth in claim 2, comprising: receiving a third signal indicative of a weather forecast; and producing the control signal based on the first signal, the at least one second signal and the third signal.

9. The method as set forth in claim 2, wherein: the at least one factor represents a lifetime consumption, a residual lifetime and/or a residual operating time of the wind turbine, wear that the wind turbine is expected for different operating points, respectively and/or costs respectively associated with different operating points for grid connection power of the wind turbine.

10. The method as set forth in claim 1, comprising: operating the wind turbine using at least two different operating characteristics including power-wind speed operating characteristics, and a threshold value for the wind turbine; in response to the first signal indicating that the remuneration is greater than or equal to the threshold value, operating, using the control signal, the wind turbine with a first of the at least two different operating characteristics; and in response to the first signal indicating that the remuneration is below the threshold value, operating, using, the control signal, the wind turbine with a second of the at least two different operating characteristics.

11. The method as set forth in claim 1, comprising: generating the control signal such that, in response to a change in the first signal within a period of time, an operating point is maintained without change.

12. The method as set forth in claim 11, wherein the period of time is at least one hour, at least 30 minutes, at least 10 minutes or 15 minutes.

13. A wind turbine, comprising: a controller configure to: generate or receive a control signal dependent on a first signal, the first signal being indicative of a remuneration for electrical energy currently fed and/or to be fed into a grid, wherein the wind turbine is coupled to the grid, wherein: the wind turbine is configured to generate a power output based on the control signal, a schedule specifying a plurality of different operating points of the wind turbine for a plurality of different time periods, respectively, is stored, and the plurality of different time periods are in a pre-defined period of time, and each operating point of the plurality of different operating points represents a setting of the wind turbine that is dependent on wind speed; and operate the wind turbine per the plurality of different operating points specified by the schedule, wherein an operating point of the wind turbine changes in response to the first signal changing by more than a pre-defined second threshold value, and the operating point of the wind turbine does not change in response to the first signal changing by less than the pre-defined second threshold value.

14. A central controller, configured to: receive a first signal indicative of a remuneration of electrical energy currently fed and/or to be fed into a grid, wherein a plurality of wind turbines are respectively connected to the grid; generate control signals for the plurality of wind turbines, respectively, based on the first signal; and control the plurality of wind turbines using the control signals, wherein: a schedule specifying a plurality of different operating points of the wind turbine for a plurality of different time periods, respectively, is stored, and the plurality of different time periods are in a pre-defined period of time, and each operating point of the plurality of different operating points represents a setting of the wind turbine that is dependent on wind speed; and operate the wind turbine per the plurality of different operating points specified by the schedule, wherein an operating point of the wind turbine changes in response to the first signal changing by more than a pre-defined second threshold value, and the operating point of the wind turbine does not change in response to the first signal changing by less than the pre-defined second threshold value.

15. A system comprising: the central controller as set forth in claim 14; and the plurality of wind turbines.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) Further configurations will be seen from the embodiments by way of example which are described in greater detail with reference to the Figures.

(2) FIG. 1 shows a wind turbine,

(3) FIG. 2 shows a plurality of wind turbines connected to a central control,

(4) FIG. 3 shows a plurality of operating characteristics of a wind turbine,

(5) FIG. 4 shows the control of a wind turbine, and

(6) FIG. 5 shows the steps in the method according to an embodiment.

DETAILED DESCRIPTION

(7) FIG. 1 shows a diagrammatic view of a wind turbine. The wind turbine 100 has a tower 102 and a nacelle 104 on the tower 102. Provided on the nacelle 104 is an aerodynamic rotor 106 having three rotor blades 108 and a spinner 110. The aerodynamic rotor 106 is driven in rotation in operation of the wind turbine by the wind and thus also rotates an electromagnetic rotor or rotor member of a generator which is directly or indirectly coupled to the aerodynamic rotor. The electric generator is arranged in the nacelle 104 and generates electrical energy. The pitch angles of the rotor blades 108 can be altered by pitch motors at the rotor blade roots of the respective rotor blades 108.

(8) FIG. 2 shows a wind farm 112 having by way of example three wind turbines 100 which can be the same or different. The three wind turbines 100 are thus representative of basically any number of wind turbines 100 in a wind farm 112. The wind turbines 100 provide their power, more specifically in particular the current generated, by way of an electrical farm grid 114. In that respect the respectively generated currents or powers of the individual wind turbines 100 are added up and there is generally provided a transformer 116 which steps up the voltage in the farm in order then to feed it into the supply grid, or referred to for brevity as the grid 120, at the feed point 118 which is also generally referred to as the PCC.

(9) In addition each of the wind turbines 100 is connected to a wind farm controller 22 by way of a data line 24. Data can be transmitted by way of the data line 24 between the wind turbines 100 and the wind farm controller 22, in both directions, that is to say from the wind turbine 100 to the wind farm controller 22 and from the wind farm controller 22 to the wind turbine 100. The wind farm controller 22 is in turn connected to a central control (central controller) 26 by way of a further data line 28.

(10) In the present case in FIG. 2 the central control 26 is only connected to the illustrated wind farm 112, wherein preferably the central control 26 is connected to and controls a plurality of wind farms 112. By way of the data line 28 the central control 26 can also transmit data to the wind farm controller 22 and the wind farm controller 22 can transmit data to the central control 26, that is to say in both directions, namely bidirectionally. The central control 26 also has a first input 30 to which a first signal 32 or a plurality of first signals 32 is or are fed. The first signal 32 specifies the level of a remuneration for electrical energy which is fed currently and/or in the future into the grid 120 to which the wind turbines 100 are connected. A plurality of first signals 32 serve for example to specify the respective remuneration for the energy when a plurality of wind farms 112 which for example are connected to different grids 120 are controlled by the central control 26. Here then each first signal 32 is provided for the wind turbines 100 of the respective wind farm 112.

(11) In additional the central control 26 is adapted to receive a second signal 34 from each of the wind turbines 100 of the illustrated wind farm 112, by way of the data line 24 and the further data line 28, being therefore forwarded by way of the wind farm controller 22, that signal being indicative of at least one factor for determining the current electricity generation costs of the respective wind turbine 100. The central control 26 also has a further input 36, by way of which a third signal 38 can be received. The third signal 38 is indicative of a weather forecast. Preferably a third signal 38 includes a plurality of weather forecasts for various regions in which, in the event that a plurality of wind farms 112 are connected to the central control 26, they are located. It is however also possible for a specific third signal 38 to be received for each wind farm 112 irrespective of its location. As an alternative to the illustrated embodiment the first input 30 and the further input 36 can also be in the form of a single input.

(12) The central control 26 which in this respect can also be in the form of a control center but also in the form of a part of the farm control in the form of a decentralized system is adapted, in dependence on the first signal 32 or in dependence on the first signal 32 and the second signal 34 or in dependence on the first signal 32 and the second signal 34 and the third signal 30 or in dependence on the first signal 32 and the third signal 38 to produce and then output a control signal 40 for actuating all wind turbines 100 of the wind farm 112 or each of the wind turbines 100 separately. The control signal or signals 40 are then suitably fed by way of the further data line 28 and the data line 24, that is to say again by way of the farm controller 22, to the or a respective one of the corresponding wind turbines 100. The control signal 40 serves for control of the wind turbine so that the wind turbine generates energy which is dependent on the control signal. Preferably the control signal 40 serves for controlling one or more wind turbines 100 by adjusting an operating point, dependent on the control signal 40, of the wind turbine 100 or wind turbines 100 so that therefore a current operating point of the wind turbine or turbines 100 changes to another operating point dependent on the control signal 40. An operating point defines for example a blade setting angle or a blade angle change and/or control of the exciter voltage of the generator of the wind turbine 100. Thus, in dependence on the control signal 40, more specifically in particular by changing the operating point, even with the wind remaining the same, it is possible to change the electrical energy generated with the wind turbine 100. The wind turbines 100 of the wind farm 112 are thus controlled in particular in dependence on the first signal 32 that is to say in dependence on the level of a remuneration.

(13) In an embodiment which is not illustrated here the above-indicated functions of the central control 26 are performed in the wind farm controller 22. For that purpose the wind farm controller 22 has inputs for receiving the first signal 32 and in particular the second signal 34 or itself producing same for the wind turbines 100 controlled by the wind farm controller 22. The wind farm controller 22 then produces control signals 40 for the wind turbines 100 in dependence on the first signal 32 and preferably in dependence on the second signal 34.

(14) FIG. 3 shows three operating characteristics 40a, 40b, 40c. The operating characteristics 40a, 40b, 40c associate a respective power output 44 with a wind speed 42. Each of the operating characteristics 40a through 40c includes a plurality of operating points 46. This means that the wind turbine which is operated for example with an optimum operating characteristic 40a, at a wind speed 42 represented by the vertical broken line 48 generates a power output 50 shown by the horizontal broken line 50.

(15) At the operating point 46 which is shown on the optimum operating characteristic 40a pre-defined blade setting angles and/or exciter field settings are suitably stored for the operating point. From that operating point 46 on the operating characteristic 40a which can also be referred to as the first operating characteristic it is possible for example to switch over to a further operating point 46 on the further or second operating characteristic 40b. The operating point 46 which is on the operating characteristic 40b for example involves a different blade setting angle or a different setting for the exciter field.

(16) Thus in dependence on the first signal which specifies the level of remuneration it is easily possible to switch between the operating points 46 on the operating characteristic 40a through 40c. In the present example three operating characteristics are shown, but in accordance with another embodiment a plurality of operating characteristics is stored, which are each associated with a respective remuneration level and can be selected in dependence on a remuneration level which is indicated by the first signal. Alternatively, in accordance with a further embodiment (not shown here) only at least one operating characteristic 40a is stored, wherein regions 49 of the operating characteristic 40a of higher power output can be deactivated or blocked off or a power limitation effect can be activated. The case does not involve storing a plurality of characteristics but the characteristic is divided into a plurality of regions, wherein the regions of higher power output are optional and can be switched on or off or blocked and re-enabled in dependence on the first signal 32.

(17) FIG. 4 shows a control (controller) 52 of a wind turbine which for example is controlled independently of a central control 26 according to the method. The control (controller) 52 receives the first signal 32 which indicates the level of a remuneration and optionally the third signal 38 which contains the weather forecast data. In addition the control 52 includes an evaluation circuit 54 which generates the second signal 34. In dependence on the three signals a control signal 40 for controlling the wind turbine is thus produced with a control signal producing unit 51 of the control 52. That control signal 40 can be used for example in the control 42 directly in an operating point setting unit 53 to control the power output of the wind turbine with a given wind, more specifically by the selection of an operating point 46.

(18) FIG. 5 shows the steps in an embodiment of the method. In a step 60 the wind turbine is in a current operating point 46. After a delay time 62 to which a period 64 can be supplied a check is made in a decision step 66 to ascertain whether a fed first signal 32 has changed. If the first signal 32 has not changed then the method goes to step 60 again and the wind turbine 100 continues to be driven at the current operating point 46. If the first signal 32 has changed a check is made in a next decision step 68 to ascertain whether the change in the first signal 32 has altered by more than a second threshold value 70. If that is not the case then the wind turbine is again further operated using the current operating point 46. If however the first signal 32 has changed by more than the second threshold value 70 the wind turbine 100 is controlled in such a way that the wind turbine 100 is operated at a different operating point in step 72.

(19) Alternatively, a threshold value 74 can additionally be added in the checking operation in step 66. A change in the first signal 32 is detected only when the first signal 32 has changed in such a way that it has exceeded the threshold value 74 once, either from a lower value to an upper value or from an upper value to a lower value.