METHOD AND SYSTEM FOR OPERATING A WIND ENERGY PLANT

Description

[0001] The present invention relates to a method and system for operating a wind turbine, as well as a computer program product for implementing the method. In wind turbines having a rotor with rotor blades that can rotate about a horizontal rotor axis, it is known per se to use a tracking drive to rotate the rotor about a vertical yaw axis in order to reduce a deviation between its rotor axis and a varying wind direction ("wind tracking").

[0002] In particular, with increasing rotor diameters, the loads on such tracking drives increase.

[0003] Reference is also made to EP 3 343 027 A1 and US 2004 / 081551 A1.

[0004] The object of the present invention is to improve the operation of a wind turbine.

[0005] This object is achieved by a method having the features of claim 1.

[0006] Claims 8 and 22 protect a system and a computer program product, respectively, for carrying out a method described herein. The subclaims relate to advantageous developments.

[0007] According to one embodiment of the present invention, a wind turbine has a rotor which, in one embodiment on, in particular in, a nacelle, is rotatable (mounted) about a rotor axis.

[0008] In one embodiment, the rotor is coupled to a generator for converting wind energy into electrical energy or has a generator; in one embodiment, the wind turbine is intended, in particular configured, or used for feeding electrical energy into a power grid.

[0009] According to the present invention, the rotor has at least two, in particular at least three, rotor blades, which or whose blade angles can be adjusted or rotated individually or separately about their (respective) blade axis, in particular by means of a blade adjustment device, in one embodiment motorized, in particular electromotive, and / or hydraulic, in one embodiment (also) during operation or when the rotor rotates about its rotor axis.

[0010] According to one embodiment of the present invention, the wind turbine has a tracking drive which, in a tracking operating mode, adjusts the rotor or its rotor axis, in particular the nacelle, relative to a tower on which it is rotatably arranged, about a yaw axis in such a way or with the proviso that a deviation between the rotor axis and a wind direction, which in one embodiment is detected or forecast, in particular a current one, in particular in a horizontal plane, is reduced ("wind tracking of the rotor") or is provided, in particular configured or used, for this purpose.

[0011] In one embodiment, this can improve the conversion of wind energy into mechanical or electrical power by the wind turbine.

[0012] In one embodiment, the yaw axis encloses an angle with a gravitational direction of no more than 30°, in particular no more than 15°. In one embodiment, the yaw axis is at least substantially vertical (aligned).

[0013] Additionally or alternatively, in one embodiment, the rotor axis encloses an angle with a direction of gravity, or the direction of gravity, of at least 60°, in particular at least 75°, and / or at most 120°, in particular at most 105°. In one embodiment, the rotor axis is at least substantially horizontal (aligned); in a further embodiment, it is (slightly) inclined relative to the horizontal, preferably by at least 2° and / or at most 10°.

[0014] Additionally or alternatively, in one embodiment, the rotor axis forms an angle with the yaw axis of at least 60°, in particular at least 75°, and / or at most 120°, in particular at most 105°. In one embodiment, the rotor and yaw axes are at least substantially perpendicular to each other.

[0015] In one embodiment, this can (further) improve the conversion of wind energy into mechanical or electrical power by the wind turbine.

[0016] In one embodiment, the tracking drive comprises one or more electric and / or hydraulic motors for electric or hydraulic wind tracking of the rotor or nacelle around the yaw axis or relative to the tower, in one embodiment using a single- or multi-stage gearbox. In one embodiment, the wind turbine comprises at least one, in particular mechanical, electric and / or hydraulic, parking brake for fixing an (angular) position of the rotor or nacelle around the yaw axis or relative to the tower.

[0017] According to the present invention, in the tracking operating mode, the blade angles of the rotor blades are adjusted about their (respective) blade axis in such a way or with the proviso that (thereby) a wind tracking movement is supported by the tracking drive.

[0018] In one embodiment, the blade angles are adjusted cyclically or periodically with the speed of the rotor around its rotor axis ("rotor speed"), whereby in one embodiment the individual (amplitudes of these) blade angle adjustment(s) of the individual rotor blades are phase-shifted relative to one another around the rotor axis, in one embodiment by a constant angle, which in one embodiment is equal to 360° divided by the number of rotor blades.

[0019] The idea behind this is that such a blade angle adjustment can aerodynamically induce a torque around the yaw axis, which can be advantageously used to support the yaw movement of the yaw drive. In this way, the loads on the yaw drive can be reduced in one design, allowing larger wind turbines to be operated with constant yaw drives, or with constant yaw drives with smaller yaw drive loads.

[0020] According to claim 16, for or during operation of the wind turbine in the tracking operating mode, the blade angles of the rotor blades are adjusted about their (respective) blade axis to support a wind tracking movement by the tracking drive, wherein an amplitude of this blade angle adjustment, in particular compared to a reference value, is reduced by or to a predetermined (first reduction) value if a yaw rate of the rotor, in particular its rotor axis, about the yaw axis, in particular in terms of amount or sign, lies in a predetermined (first) reduction speed range that can be set in one embodiment, which has a (first) lower reduction speed limit, in particular is limited (downwardly) by this.

[0021] Additionally or alternatively, according to claim 16, for or during operation of the wind turbine in the tracking operating mode, the blade angles of the rotor blades are adjusted about their (respective) blade axis to support a wind tracking movement by the tracking drive, wherein an amplitude of this blade angle adjustment, in particular compared to a or the reference value, is increased by or to a predetermined (first increase) value if a yaw rate of the rotor about the yaw axis, in particular in terms of amount or sign, lies in a predetermined (first) increase speed range that can be set in one embodiment, which has a (first) upper increase speed limit, in particular is limited (upwards) by this.

[0022] In one embodiment, the amplitude of the blade angle adjustment to support a wind tracking movement by the tracking drive has the reference value, determined in one embodiment, which is in particular constant, in particular adjustable, or variable, if the yaw rate is below the (first) reduction speed range or the (first) lower reduction speed limit and / or above the (first) increase speed range or the (first) upper increase speed limit, in particular within a normal speed range, as well as the (first reduction) value reduced in comparison thereto if the yaw rate is within the (first) reduction speed range and / or the (first increase) value increased in comparison thereto if the yaw rate is within the (first) increase speed range.

[0023] This is based in particular on the idea that such a step-like reduction or increase in one design can achieve a more stable operating behavior while at the same time advantageously converting wind energy into mechanical or electrical power by the wind turbine.

[0024] In one embodiment, the amplitude of the blade pitch adjustment to support a wind yaw movement is reduced or downgraded by the tracking drive in steps by or to the (first) reduction value if the yaw rate, in particular in terms of magnitude or sign, exceeds the (first) lower reduction speed limit. Additionally or alternatively, the amplitude of the blade pitch adjustment to support a wind yaw movement is increased or upgraded by or to the (first) increase value if the yaw rate, in particular in terms of magnitude or sign, falls below the (first) upper increase speed limit.

[0025] This is based in particular on the idea of ​​reducing the support of a wind yaw movement induced by the tracking drive through the blade angle adjustment in the case of a (too) high yaw rate, or increasing the support of a wind yaw movement induced by the tracking drive through the blade angle adjustment in the case of a (too) low yaw rate.

[0026] In one embodiment, in the tracking operating mode, no or at least one reduction speed range, in particular at least two reduction speed ranges, and / or at most four reduction speed ranges, in a preferred embodiment exactly one reduction speed range or exactly two reduction speed ranges, is / are provided, for which the amplitude of the blade angle adjustment is (in each case) reduced in a speed range-specific manner or by or to the corresponding (speed range-specific reduction) value.

[0027] Additionally or alternatively, in an embodiment in the tracking operating mode, no or at least one increase speed range, in particular at least two increase speed ranges, and / or at most four increase speed ranges, in a preferred embodiment exactly one increase speed range or exactly two increase speed ranges, is / are provided, for which the amplitude of the blade angle adjustment is (in each case) increased speed range-specifically or by or to the corresponding (speed range-specific increase) value.

[0028] The underlying idea is that such a highly limited speed range or number of stages in a single design can achieve particularly stable operating behavior while simultaneously advantageously converting wind energy into mechanical or electrical power by the wind turbine. Additionally or alternatively, this can make sensor technology and / or operational control more robust in a single design, and / or advantageously retrofit existing wind turbines, preferably with little or no hardware modifications, and / or limit and / or more easily control the effects of a fault.

[0029] Accordingly, in one embodiment, the blade angles are adjusted in the tracking operating mode, wherein the amplitude of the blade angle adjustment is reduced by or to a predetermined (second reduction) value to support a wind tracking movement by the tracking drive if the yaw rate, in particular in terms of amount or sign, lies in a predetermined, in one embodiment adjustable, second reduction speed range, which has a second lower reduction speed limit, in particular is limited (downward) by this, and / or is increased by or to a predetermined (second increase) value if the yaw rate, in particular in terms of amount or sign, lies in a predetermined, in one embodiment adjustable, second increase speed range, which has a second upper increase speed limit, in particular is limited (downward) by this.

[0030] In one embodiment, the first or second reduction speed range can be open on one side or upwards or have a (first or second) upper reduction speed limit or be limited (upwards) by this. Additionally or alternatively, in one embodiment, the first or second increase speed range can be open on one side or downwards or have a (first or second) lower increase speed limit or be limited (downwards) by this. In one embodiment, the second lower reduction speed limit is equal to the first upper reduction speed limit and / or the second upper increase speed limit is equal to the first lower increase speed limit. In one embodiment, the first or second upper reduction speed limit can be equal to a maximum possible or permissible yaw rate of the rotor about the yaw axis or (theoretically or mathematically) infinite orAs already mentioned, the first or second reduction speed range can be open-ended. Additionally or alternatively, in one embodiment, the first or second lower increase speed limit can be zero or negative. This advantageously also covers (rare) cases in which the rotor is forced in a direction opposite to the desired tracking movement, for example, due to unexpected turbulence or the like.Additionally or alternatively, in one embodiment, the (first) upper increase speed limit is smaller than the (first) lower reduction speed limit, in particular the (first) lower reduction speed limit and / or the (first) upper increase speed limit can limit a normal speed range in which a reference value of the amplitude of the blade pitch adjustment to support a wind tracking movement by the tracking drive is neither reduced nor increased.

[0031] In one embodiment, the amplitude of the blade pitch adjustment is reduced by the first reduction value when the first lower reduction speed limit is exceeded, and is reduced again by the same or a different reduction value when the (higher) second lower reduction speed limit is exceeded. In one embodiment, the amplitude of the blade pitch adjustment is reduced to the first reduction value when the first lower reduction speed limit is exceeded, and is reduced to the second reduction value, which is smaller than the first reduction value, when the (higher) second lower reduction speed limit is exceeded.

[0032] In one embodiment, the amplitude of the blade pitch adjustment is reduced by the first increase value when the first upper increase speed limit is undershot, and is reduced again by the same or a different increase value when the (lower) second upper increase speed limit is undershot. In one embodiment, the amplitude of the blade pitch adjustment is reduced to the first increase value when the first lower increase speed limit is undershot, and is reduced to the second increase value, which is smaller than the first increase value, when the (lower) second lower increase speed limit is undershot.

[0033] In one embodiment, the first and / or second reduction and / or increase speed range and / or the normal speed range (each) extends over at least 0.05° per second [° / s], in particular at least 0.1° per second, in one embodiment at least 0.2° per second.

[0034] As a result, in one embodiment, in particular in combination of two or more of the above-mentioned embodiments, a particularly stable operating behavior can be achieved with simultaneous advantageous conversion of wind energy into mechanical or electrical power by the wind turbine.

[0035] In one embodiment, the method comprises the steps, in one embodiment chronological or sequential, of: Determining a wind yaw requirement, in one embodiment by determining, in particular by measuring, a deviation between a, in particular current or averaged, wind direction and the rotor axis direction, in particular its horizontal component; determining the amplitude of the blade angle adjustment to support the wind yaw movement by the tracking drive, in particular the reference value, in one embodiment based on a mapping, in particular empirically and / or with the aid of a simulation, predetermined, in particular stored and / or adjustable, of wind yaw requirement values ​​to one or more blade angle adjustment amplitude values, in particular with the aid of a characteristic map or the like; adjusting the individual blade angles of the rotor blades based on this determined amplitude. Determining, in particular by measuring or predicting, an actual value of the yaw rate of the rotor about the yaw axis; at least one of the following steps: gradually reducing the determined amplitude if the actual value exceeds one or more predetermined, in particular adjustable (lower reduction) speed limits; and / or gradually increasing the determined amplitude if the actual value falls below one or more predetermined, in particular adjustable (upper increase) speed limits;and the step: (if necessary) setting or adjusting the individual blade angles of the rotor blades on the basis of this determined amplitude, which has been reduced or increased by one or more stages. According to claim 21, a system for operating the wind turbine is configured, in particular in terms of hardware and / or software, in particular programming, to carry out a method described here and / or comprises: means for adjusting blade angles of the rotor blades about their blade axis to support a wind yaw movement by the tracking drive in a tracking operating mode, and at least one of: means for reducing an amplitude of this blade angle adjustment by or to a predetermined value if a yaw rate of the rotor about the yaw axis lies in a predetermined reduction speed range which has a lower reduction speed limit;and / or means for increasing an amplitude of said blade pitch adjustment by or to a predetermined value if a yaw rate of the rotor about the yaw axis lies within a predetermined increase rate range having an upper increase rate limit. ;

[0036] According to claim 9, for or during operation of the wind turbine in the tracking operating mode, the blade angles of the rotor blades are adjusted about their (respective) blade axis to support a wind tracking movement by the tracking drive, wherein an amplitude of this blade angle adjustment is adjusted as a function of a rotor torque about the rotor axis.

[0037] In one embodiment, the amplitude is increased from a first to a second value, in particular in terms of magnitude or sign, if the rotor torque has a larger second value, in particular in terms of magnitude or sign, instead of a first value, or is reduced from a second to a first value if the rotor torque has a smaller first value, in particular in terms of magnitude or sign, instead of a second value.

[0038] This is based in particular on the idea that a torque about the rotor axis in one embodiment represents a particularly suitable indicator for adjusting the amplitude of the blade pitch adjustment to support the yaw movement by the tracking drive, as it reflects a load or stress condition of the wind turbine particularly well. For example, higher wind loads generally lead to greater rotor moments and at the same time require greater support of a wind yaw movement induced by the tracking drive through the blade pitch adjustment. Additionally or alternatively, in one embodiment, an already existing or known rotor torque, particularly for controlling the wind turbine, can advantageously be used in addition to the blade pitch adjustment to support a wind yaw movement by the tracking drive.

[0039] Accordingly, in one embodiment, a more stable operating behavior can be achieved while at the same time advantageously converting wind energy into mechanical or electrical power by the wind turbine.

[0040] In one embodiment, the amplitude of the blade pitch adjustment to support a yaw movement by the tracking drive is zero or is set to zero if the rotor torque, in particular in terms of magnitude or sign, falls below a predetermined torque limit, which in one embodiment is greater than zero. In other words, in one embodiment, a blade pitch adjustment, in particular a cyclical adjustment, to support the yaw movement by the tracking drive is suppressed if or as long as the rotor torque, in particular in terms of magnitude or sign, falls below a predetermined torque limit.

[0041] This is based in particular on the idea that, in one embodiment, on the one hand, below certain loads, support of a wind tracking movement induced by the tracking drive by means of the blade angle adjustment is not required, and on the other hand, by suppressing such a blade angle adjustment or reducing or adjusting its amplitude to zero, a deterioration in the conversion of wind energy into mechanical or electrical power by the wind turbine induced by this blade angle adjustment can be avoided and thus a conversion of wind energy into mechanical or electrical power by the wind turbine can be improved.

[0042] In one embodiment, the rotor torque is determined on the basis of a torque setpoint; in particular, it can be a torque setpoint.

[0043] This is based in particular on the idea that, in one embodiment, target values ​​are less subject to measurement errors, and in particular less noisy, than the actual values ​​usually measured.

[0044] In one embodiment, the rotor torque can be determined indirectly, for example, by dividing the power at the rotor or a gear or generator shaft coupled to it by the speed of that shaft. In one embodiment, this can improve the determination, in particular simplify it, and / or increase its precision. Generally, a rotor torque is understood to mean, in particular, a torque acting on or exerted by the rotor.

[0045] According to claim 9, for or during operation of the wind turbine in the tracking operating mode, the blade angles of the rotor blades are adjusted about their (respective) blade axis to support a wind tracking movement by the tracking drive, wherein an amplitude of this blade angle adjustment is (also) adjusted as a function of a wind tracking direction of the rotor about the yaw axis.

[0046] This is based in particular on the idea that - particularly due to the so-called tilt angle, i.e. as a result of a (slight) inclination of the rotor axis relative to the horizontal, which in one design is at least 2° and / or at most 10° - a torque is already induced aerodynamically around the yaw axis, which acts in one direction, even without blade pitch adjustment. If the rotor is to be yaw-tracked in this direction, or if a yaw-tracking movement is to be supported by the yaw drive in this direction through blade pitch adjustment, this requires a correspondingly lower torque around the yaw axis induced by the, in particular cyclical, blade pitch adjustment than conversely for yaw-tracking (movement) in the opposite direction, or against the direction in which the torque around the yaw axis induced without blade pitch adjustment acts or seeks to rotate the rotor.

[0047] Accordingly, in one embodiment, the amplitude of the blade angle adjustment to support a yaw movement is set by the tracking drive in such a way that they have an offset from one another in a first yaw direction and in a second yaw direction in the opposite direction, in particular under otherwise identical (ambient) conditions, wherein this offset is constant in one embodiment. In another embodiment, the offset depends on the rotor torque or rather the rotor torque, and in a further development, it is linear. In particular, the offset can thus increase with increasing rotor torque, in one embodiment (directly) proportionally. In one embodiment, the offset is or is predetermined, in particular set, or predetermined, in particular adjustable. Accordingly, it is or isIn one embodiment, the offset (which is then constant during operation) or the dependence on the rotor torque, in particular a proportionality factor between rotor torque and offset, is specified, in particular set, or specified, in particular adjustable.

[0048] In one embodiment, this allows for a more stable operating behavior and / or a particularly advantageous conversion of wind energy into mechanical or electrical power by the wind turbine.

[0049] According to claim 9, for or during operation of the wind turbine in the tracking operating mode, the blade angles of the rotor blades are adjusted about their (respective) blade axis to support a wind yaw movement by the tracking drive, in particular individually and / or cyclically, wherein the blade angles are additionally adjusted by a lead angle as a function of an amplitude of this blade angle adjustment in such a way or with the proviso that even with maximum blade angle adjustment to support a wind yaw movement by the tracking drive, a minimum blade angle is or can be maintained. In one embodiment, a blade angle is maximum when the rotor blade has a so-called feathering position in which the conversion of wind energy into mechanical or electrical power is minimal. Accordingly, a minimum blade angle refers to a maximum permissible adjustment away from the feathering position orto a position in which the conversion of wind energy into mechanical or electrical power is maximum.

[0050] This is based in particular on the idea that the blade angle adjustment to support a wind tracking movement by the tracking drive could cause the blade angle to fall below a minimum blade angle, which would indicate an overload of the rotor blades and / or a flow separation at the rotor blades.

[0051] Accordingly, in one embodiment, in addition to the blade angle adjustment to support a wind tracking movement, the blade angles are adjusted by the tracking drive by a lead angle dependent on the amplitude of this blade angle adjustment, wherein this adjustment by the lead angle preferably takes place in the direction of the vane position of the rotor blades, in which the conversion of wind energy into mechanical or electrical power is or becomes minimal.

[0052] In one embodiment, the blade angles are adjusted collectively by the (common) lead angle. Additionally or alternatively, the lead angle is at least 0.5° and / or at most 5°.

[0053] In one embodiment, this allows for a more stable operating behavior and / or a particularly advantageous conversion of wind energy into mechanical or electrical power by the wind turbine.

[0054] In one embodiment, the method comprises the steps: Determining a wind yaw requirement, in one embodiment by determining, in particular by measuring, a deviation between a, in particular current or averaged, wind direction and the rotor axis direction, in particular its horizontal component; determining the amplitude of the blade angle adjustment to support the wind yaw movement by the tracking drive, in one embodiment based on a mapping of wind yaw requirement values ​​to blade angle adjustment amplitude values, in particular empirically and / or with the aid of a simulation, predetermined, in particular stored and / or adjustable, in particular with the aid of a characteristic map or the like; and adjusting the individual blade angles of the rotor blades based on this amplitude, wherein this amplitude is determined as a function of a rotor torque about the rotor axis and / or a wind tracking direction of the rotor about the yaw axis and / or the blade angles are adjusted as a function of a determined lead angle to maintain a minimum blade angle.

[0055] Accordingly, the method comprises at least one of the following steps: Determining the rotor torque; determining the yaw direction; and / or determining the lead angle.

[0056] As already mentioned, according to one embodiment of the present invention, a system for operating the wind turbine, in particular hardware and / or software, in particular program-related, is configured to carry out a method described here. Accordingly, according to one embodiment according to claim 15, it comprises: Means for adjusting blade angles of the rotor blades about their blade axis to support a wind tracking movement by the tracking drive in a tracking operating mode and at least one of: Means for adjusting an amplitude of this blade angle adjustment as a function of a rotor torque about the rotor axis and / or a wind tracking direction of the rotor about the yaw axis; and / or means for adjusting the blade angles additionally (to the blade angle adjustment to support a wind tracking movement by the tracking drive) by a lead angle as a function of an amplitude of this blade angle adjustment (to support a wind tracking movement by the tracking drive) to maintain a minimum blade angle.

[0057] According to an embodiment according to claim 2, for or during operation of the wind turbine in the tracking operating mode, the blade angles of the rotor blades are adjusted about their (respective) blade axis to support a wind tracking movement by the tracking drive, wherein the tracking drive is activated to track the wind of the rotor about the yaw axis by a predetermined, in one embodiment adjustable, in particular constant, or variable waiting time after the blade angle adjustment of the rotor blades about their blade axis to support this wind tracking movement.

[0058] In one embodiment, the blade pitch adjustment of the rotor blades is thus initially activated to support the yaw movement, and after the waiting time, the tracking drive is then activated to execute the yaw movement induced by it. If, in a preferred embodiment, the wind turbine has at least one parking brake, in one embodiment, after a predetermined (first) waiting time, which can be set in one embodiment and is in particular constant or variable, after activation of the blade pitch adjustment, this parking brake is initially released, and after a predetermined (second) further waiting time, which can be set in one embodiment and is in particular constant or variable, after release of the parking brake, the tracking drive is activated, so that the tracking drive is activated for a waiting time after the blade pitch adjustment to support the yaw movement, which is equal to the sum of these two waiting times.

[0059] This is based in particular on the idea that particularly high loads can act on the drive at the beginning of a tracking operating mode, for example due to mass inertia, static friction, or the like. By activating the blade pitch adjustment to support a wind tracking movement by the tracking drive in advance, high initial loads can advantageously be at least partially absorbed or compensated for by the blade pitch adjustment in one embodiment. Additionally or alternatively, in one embodiment, such advance of the blade pitch adjustment to support a wind tracking movement by the tracking drive can advantageously already produce or form a corresponding supporting, aerodynamically induced torque.

[0060] In this way, in one embodiment, loads on the tracking drive can be reduced, in particular larger wind turbines can be operated with constant tracking drives or constant wind turbines can be operated with smaller tracking drive (loads).

[0061] In one embodiment, the waiting time is specified as a function of a rotor rotation frequency, a wind speed and / or a rotor torque around the rotor axis.

[0062] The specification dependent on a rotor rotation frequency is based in particular on the idea that at higher rotor rotation frequencies, a corresponding, in particular sufficient, supporting torque around the yaw axis can be built up more quickly by the tracking drive through the blade angle adjustment to support a wind tracking movement. Accordingly, in one embodiment, at a first rotor rotation frequency, the tracking drive is activated to yaw the rotor around the yaw axis for a first waiting time after the blade angle adjustment of the rotor blades around their blade axis to support this wind tracking movement, and at a higher second rotor rotation frequency, the second waiting time is shorter after the blade angle adjustment.

[0063] Similarly, the specification depending on a wind speed is based in particular on the idea that at higher wind speeds, a corresponding, in particular sufficient, supporting torque around the yaw axis can be built up more quickly by the tracking drive through the blade angle adjustment to support a wind yaw movement. Accordingly, in one embodiment, at a first wind speed, the tracking drive is activated to yaw the rotor around the yaw axis for a first waiting time after the blade angle adjustment of the rotor blades around their blade axis to support this wind yaw movement, and at a higher second wind speed, for a shorter second waiting time after the blade angle adjustment.

[0064] The specification dependent on a rotor torque is based in particular on the previously explained idea that a torque about the rotor axis can represent a particularly suitable indicator for the (setting of the) waiting time, as it reflects the load or stress state of the wind turbine particularly well. For example, higher wind loads generally lead to larger rotor torques and, at the same time, require greater support of a wind tracking movement induced by the tracking drive through the blade pitch adjustment. Additionally or alternatively, in one embodiment, an already existing or known rotor torque, particularly for controlling the wind turbine, can be used in addition to determining the waiting time.Accordingly, in one embodiment, at a first rotor torque, the tracking drive is activated to yaw the rotor around the yaw axis for a first waiting time after the blade pitch adjustment of the rotor blades around their blade axis to support this yaw movement, and at a higher second rotor torque, for a longer second waiting time after the blade pitch adjustment.

[0065] In this way, in particular in combination with two or three of the above-mentioned influencing variables rotor rotation frequency, wind speed and rotor torque, a short waiting time can be advantageously implemented depending on the situation and thus the wind yaw can be accelerated overall.

[0066] In one embodiment, the tracking drive for yaw tracking of the rotor around the yaw axis is deactivated together or, at least substantially, simultaneously with the blade pitch adjustment of the rotor blades around their blade axis to support this yaw movement.

[0067] This is based in particular on the idea that smaller loads can act on the drive at the end of a yaw mode. By deactivating the blade pitch adjustment to support a wind yaw movement together with the yaw drive, a deterioration in the conversion of wind energy into mechanical or electrical power resulting from this blade pitch adjustment can be stopped more quickly, thus improving the conversion of wind energy into mechanical or electrical power by the wind turbine.

[0068] In another embodiment, the tracking drive for yaw tracking of the rotor around the yaw axis is deactivated by a predetermined lead time before the blade pitch adjustment of the rotor blades around their blade axis to support this yaw movement.

[0069] In this way, in one embodiment, loads of the tracking drive can be further reduced, in particular larger wind turbines can be operated with constant tracking drives or constant wind turbines can be operated with smaller tracking drive (loads).

[0070] In one embodiment, the waiting time between the activation of the blade pitch adjustment and the activation of the tracking drive is at least 0.25 seconds or 250 ms, in particular at least 0.5 seconds or 500 ms, and / or at most 30 seconds, in particular at most 5 seconds, in one embodiment at most 2.5 seconds.

[0071] In this way, the duration of wind tracking and the load on the tracking drive can be minimized in one design.

[0072] According to the invention, according to claim 1, for or during operation of the wind turbine in the tracking mode, the blade angles of the rotor blades are adjusted about their (respective) blade axes to support a wind tracking movement by the tracking drive, wherein a commanded phase shift of an amplitude of this blade angle adjustment relative to a rotor-fixed reference angular position about the rotor axis is dynamically adjusted as a function of a rotor rotation frequency of the rotor about the rotor axis. In one embodiment, the rotor-fixed reference angular position is determined based on a determined, in particular measured, rotor (rotational) position.

[0073] Due in particular to mechanical, hydraulic, electrical, especially electromotive or magnetic, and / or signaling inertia, a commanded amplitude of the blade pitch adjustment is only realized with a certain delay. Furthermore, transient aerodynamics cause a delay in the buildup of the supporting torque around the yaw axis induced by the blade pitch adjustment. This impairs the support of a wind tracking movement induced by the yaw drive through the blade pitch adjustment.

[0074] These delays can be at least partially compensated by a phase shift of the commanded amplitude of the blade pitch adjustment compared to a rotor-fixed reference angular position, thus improving the support.

[0075] If, as already explained above, the individual (amplitudes of the) blade angle adjustment(s) of the individual rotor blades are phase-shifted relative to one another about the rotor axis, then in one embodiment all (amplitudes of the) blade angle adjustment(s) of the individual rotor blades are additionally phase-shifted by the same value relative to a rotor-fixed reference angular position about the rotor axis, which thus represents a commanded phase shift of an amplitude of the blade angle adjustment to support a wind yaw movement by the tracking drive within the meaning of the present invention. A commanded phase shift within the meaning of the present invention is, in one embodiment, a phase shift that is output, in particular currently, by a controller and / or as a target value or a, in particular current, target value.

[0076] The dynamic adjustment of the commanded phase shift as a function of a rotor rotation frequency is based in particular on the idea that at higher rotor rotation frequencies the commanded phase shift must be maintained more strongly in order to be able to provide support for a wind tracking movement by the tracking drive aerodynamically in a timely manner and at a sufficient height.

[0077] Accordingly, in one embodiment, the commanded phase shift has a first phase shift value for a first value of the rotor rotation frequency and a second phase shift value that is larger, in particular in terms of amount, for a larger second value of the rotor rotation frequency.

[0078] In addition to a rotor rotation frequency-dependent or dynamic component, the commanded phase shift can also have a rotor rotation frequency-independent or static component in one embodiment.

[0079] In one embodiment, this advantageously allows mechanical, hydraulic, electrical, in particular electromotive or magnetic and / or signaling inertias to be at least partially compensated.

[0080] In one embodiment, the method comprises the steps: Determining a wind yaw requirement, in one embodiment by determining, in particular by measuring, a deviation between a, in particular current or averaged, wind direction and the rotor axis direction, in particular its horizontal component; determining the amplitude of the blade angle adjustment to support the wind yaw movement by the tracking drive, in one embodiment based on a mapping of wind yaw requirement values ​​to blade angle adjustment amplitude values, in particular empirically and / or with the aid of a simulation, predetermined, in particular stored and / or adjustable, in particular with the aid of a characteristic map or the like; and adjusting the individual blade angles of the rotor blades based on this amplitude, and the steps: determining a rotor rotation frequency; determining a phase shift of the amplitude as a function of the rotor rotation frequency; and adjusting the individual blade angles of the rotor blades based on this phase shift; and / or the step: activating the tracking drive to yaw the rotor around the yaw axis for a predetermined waiting time after activating the blade angle adjustment of the rotor blades around their blade axis to support this yaw movement. In one embodiment, a rotor (rotational) position is determined, in particular recorded by measurement, and a rotor-fixed reference angular position, to which the phase shift is related, is determined based on this rotor (rotational) position.

[0081] A means within the meaning of the present invention can be designed in hardware and / or software, in particular a processing unit, in particular a microprocessor unit (CPU), graphics card (GPU) or the like, which is preferably connected to a memory and / or bus system in terms of data or signals, and / or can have one or more programs or program modules. The processing unit can be designed to execute instructions implemented as a program stored in a memory system, to detect input signals from a data bus, and / or to output signals to a data bus. A memory system can have one or more, in particular different, storage media, in particular optical, magnetic, solid-state, and / or other non-volatile media. The program can be designed in such a way that it embodies the methods described here oris capable of executing, so that the processing unit can execute the steps of such methods and thus, in particular, can operate the wind turbine. In one embodiment, a computer program product can comprise, in particular be, a storage medium, in particular a non-volatile one, for storing a program or with a program stored thereon, wherein executing this program causes a system or a controller, in particular a computer, to execute a method described here or one or more of its steps.

[0082] In one embodiment, one or more, in particular all, steps of the method are carried out completely or partially automatically, in particular by the system or its means.

[0083] In one version, the system includes the wind turbine.

[0084] One aspect of the present invention relates, according to claim 16, to a method for operating a wind turbine according to one of claims 1 to 7, wherein an amplitude of this blade angle adjustment is reduced by or to a predetermined value if a yaw rate of the rotor about the yaw axis lies within a predetermined reduction speed range having a lower reduction speed limit; and / or is increased by or to a predetermined value if a yaw rate of the rotor about the yaw axis lies within a predetermined increase speed range having an upper increase speed limit.

[0085] In a further development of this aspect, the method is characterized in that in the tracking mode, the amplitude of the blade angle adjustment to support a wind tracking movement by the tracking drive is reduced by or to a predetermined value if the yaw rate is within a predetermined second reduction speed range having a second lower reduction speed limit; and / or is increased by or to a predetermined value if the yaw rate is within a predetermined second increase speed range having a second upper increase speed limit.

[0086] Additionally or alternatively, the method in a further development of this aspect is characterized in that in the tracking mode at least one, in particular at least two, and / or at most four reduction speed ranges, in particular exactly one or two reduction speed ranges, are provided, for which the amplitude of the blade angle adjustment is reduced in a speed-range-specific manner; and / or at least one, in particular at least two, and / or at most four increase speed ranges, in particular exactly one or two increase speed ranges, are provided, for which the amplitude of the blade angle adjustment is increased in a speed-range-specific manner.

[0087] In a further development of the aspect, in particular one of its above-mentioned developments, the method is characterized in that a speed range extends over at least 0.05° per second.

[0088] In a further development of the aspect, in particular one of its above-mentioned developments, the procedure is characterized by the steps: Determining a wind yaw requirement; determining the amplitude of the blade angle adjustment to support the wind yaw movement by the tracking drive; adjusting the individual blade angles of the rotor blades based on this amplitude; determining an actual value of the yaw rate of the rotor about the yaw axis; gradually reducing the determined amplitude if the actual value exceeds one or more specified speed limits; and / or gradually increasing the determined amplitude if the actual value falls below one or more specified speed limits; and adjusting the individual blade angles of the rotor blades based on this amplitude.

[0089] The aspect of the present invention also relates to a system according to claim 21, wherein the system is arranged to carry out a method according to one of claims 16 to 20 and / or comprises: Means for adjusting blade angles of the rotor blades about their blade axis to support a wind tracking movement by the tracking drive in a tracking operating mode, and means for reducing an amplitude of this blade angle adjustment by or to a predetermined value if a yaw rate of the rotor about the yaw axis lies in a predetermined reduction speed range having a lower reduction speed limit; and / or means for increasing an amplitude of this blade angle adjustment by or to a predetermined value if a yaw rate of the rotor about the yaw axis lies in a predetermined increase speed range having an upper increase speed limit.

[0090] One aspect of the present invention relates to a method for operating a wind turbine according to claim 9, wherein an amplitude of this blade angle adjustment is determined as a function of a rotor torque about the rotor axis and / or a yaw direction of the rotor about the yaw axis; and / or wherein the blade angles are additionally adjusted by a lead angle to maintain a minimum blade angle depending on an amplitude of this blade angle adjustment.

[0091] In a further development of this aspect, the method is characterized in that the amplitude of the blade angle adjustment to support a wind tracking movement by the tracking drive is zero if the rotor torque falls below a predetermined torque limit.

[0092] Additionally or alternatively, the method in a further development of this aspect is characterized in that the rotor torque is determined on the basis of a torque setpoint.

[0093] In a further development of the aspect, in particular one of its above-mentioned further developments, the method is characterized in that the amplitude of the blade angle adjustment to support a wind tracking movement by the tracking drive in a first wind tracking direction and the amplitude of the blade angle adjustment to support a wind tracking movement by the tracking drive in a second wind tracking direction opposite thereto have an offset, in particular a predetermined and / or constant offset or an offset dependent on a rotor torque.

[0094] In a further development of the aspect, in particular one of its above-mentioned developments, the method is characterized in that the blade angles are collectively adjusted by the lead angle.

[0095] In a further development of the aspect, in particular one of its above-mentioned developments, the procedure is characterized by the steps: Determining a yaw requirement; determining the amplitude of the blade pitch adjustment to support the yaw movement by the yaw drive; and adjusting the individual blade angles of the rotor blades based on this amplitude, wherein this amplitude is determined as a function of a rotor torque around the rotor axis and / or a wind tracking direction of the rotor around the yaw axis and / or the blade angles are adjusted depending on a determined lead angle to maintain a minimum blade angle.

[0096] One aspect of the present invention also relates to a system according to claim 15, wherein the system is arranged to carry out a method according to one of claims 9 to 14 is and / or has: Means for adjusting blade angles of the rotor blades about their blade axis to support a wind tracking movement by the tracking drive in a tracking operating mode, as well as means for adjusting an amplitude of this blade angle adjustment as a function of a rotor torque about the rotor axis and / or a wind tracking direction of the rotor about the yaw axis; and / or means for adjusting the blade angles to maintain a minimum blade angle additionally by a lead angle as a function of an amplitude of this blade angle adjustment.

[0097] One aspect of the present invention relates to a method for operating a wind turbine according to claim 1, which a rotor rotatable about a rotor axis with at least two rotor blades individually adjustable about their blade axis and a tracking drive for wind tracking of the rotor about a yaw axis, wherein in a tracking operating mode blade angles of the rotor blades are adjusted about their blade axis to support a wind tracking movement by the tracking drive, wherein a commanded phase shift of an amplitude of this blade angle adjustment relative to a rotor-fixed reference angular position about the rotor axis is dynamically adjusted as a function of a rotor rotation frequency of the rotor about the rotor axis.

[0098] In a further development of this aspect, the method is characterized in that the tracking drive is activated for wind tracking of the rotor about the yaw axis for a predetermined waiting time after the blade angle adjustment of the rotor blades about their blade axis to support this wind tracking movement, wherein the waiting time is predetermined as a function of a rotor rotation frequency, a wind speed and / or a rotor torque about the rotor axis.

[0099] Additionally or alternatively, in a further development of this aspect, the method is characterized in that the tracking drive for wind tracking of the rotor about the yaw axis is deactivated together with the blade angle adjustment of the rotor blades about their blade axis to support this wind tracking movement or by a predetermined lead time before this blade angle adjustment.

[0100] In a further development of the aspect, in particular one of its above-mentioned developments, the method is characterized in that the waiting time is at least 0.25 seconds and / or at most 30 seconds.

[0101] In a further development of the aspect, in particular one of its above-mentioned developments, the method is characterized in that the commanded phase shift additionally has a static component that is independent of the rotor rotation frequency.

[0102] In a further development of the aspect, in particular one of its above-mentioned further developments, the method is characterized in that the commanded phase shift has a first phase shift value for a first value of the rotor rotation frequency and a larger second phase shift value for a larger second value of the rotor rotation frequency.

[0103] In a further development of the aspect, in particular one of its above-mentioned developments, the method comprises the steps: Determining a yaw requirement; determining the amplitude of the blade pitch adjustment to support the yaw movement by the yaw drive; and adjusting the individual blade angles of the rotor blades based on this amplitude, wherein the method comprises the steps of: determining a rotor rotation frequency; determining a phase shift of the amplitude as a function of the rotor rotation frequency; and adjusting the individual blade angles of the rotor blades based on this phase shift; and / or the step of: activating the tracking drive to yaw the rotor around the yaw axis for a predetermined waiting time after activating the blade angle adjustment of the rotor blades around their blade axis to support this yaw movement.

[0104] One aspect of the present invention relates, according to claim 8, to a system for operating a wind turbine, which has a rotor rotatable about a rotor axis with at least two rotor blades individually adjustable about their blade axis and a tracking drive for tracking the wind of the rotor about a yaw axis, wherein the system is designed to carry out a method according to one of claims 1 to 7 and / or comprises: Means for adjusting blade angles of the rotor blades about their blade axis to support a wind tracking movement by the tracking drive in a tracking operating mode and means for dynamically adjusting a commanded phase shift of an amplitude of this blade angle adjustment with respect to a rotor-fixed reference angular position about the rotor axis as a function of a rotor rotation frequency of the rotor about the rotor axis.

[0105] The invention also relates to a computer program product according to claim 22.

[0106] Further advantages and features emerge from the subclaims and the exemplary embodiments. The following shows, partly schematically: Fig. 1 : a system for operating a wind turbine according to an embodiment of the present invention; Fig. 2 : a method for operating the wind turbine; Fig. 3 : a method for operating the wind turbine; Fig. 4 : a method for operating the wind turbine.

[0107] Fig. 1 shows a system for operating a wind turbine according to an embodiment of the present invention.

[0108] The wind turbine has a tower 110 on which a nacelle 120 is mounted so as to be rotatable about an at least substantially vertical yaw axis G.

[0109] A rotor 130 is mounted on the nacelle 120 so as to be rotatable about a rotor axis R, which rotor has a generator or a gear-generator unit 140 or is coupled thereto in order to feed electrical energy into a power grid 150.

[0110] In the exemplary embodiment, the rotor has three rotor blades 30 that can be individually adjusted about their (respective) blade axis B. For this purpose, a controller 100 controls the corresponding blade adjustment device (not shown).

[0111] The wind turbine has a tracking drive 20 with one or more electric motor(s) and / or gear(s) for twisting or tracking the nacelle 120 and thus the rotor 130 around the yaw axis G depending on the wind direction, which is also controlled by the controller 100.

[0112] The controller 100 executes a method for operating the wind turbine according to an embodiment of the present invention.

[0113] In a version that Fig. 2 As shown, in a first step S10, the controller 100 uses a wind vane 10 to determine a deviation between a wind direction and the horizontal component of the rotor axis (oriented into the nacelle 120).

[0114] If this deviation exceeds a predetermined minimum value (S20: "Y"), the controller 100 determines that a wind tracking requirement exists and switches to a tracking operating mode; otherwise (S20: "N") the method or control returns to step S10.

[0115] In the tracking mode, in a step S30, it determines an amplitude of a cyclic blade pitch adjustment of the rotor blades 30 to support a wind tracking movement by the tracking drive, in order to rotate the nacelle 120 and thus the rotor 130 about the yaw axis G in such a way that the deviation is reduced ("wind tracking movement by the tracking drive"). This amplitude can, for example, be a stored, constant reference value or one read from a characteristic map.

[0116] In a step S40, it adjusts the blade angle of the rotor blades 30 according to this amplitude and also controls the tracking drive 20 so that it rotates the nacelle 120 and thus the rotor 130 about the yaw axis G in such a way that the deviation is reduced.

[0117] In step S40, it also determines an actual value of the yaw rate of the nacelle and thus of the rotor around the yaw axis.

[0118] If this value exceeds a predetermined (first) lower reduction speed limit (S50: "Y"), in a step S55 the amplitude determined in step S30 is reduced to or by a predetermined value and the method or the control continues with step S60.

[0119] Otherwise (S50: "N"), the method or control proceeds directly to step S60, ie without reducing the amplitude determined in step S30.

[0120] In step S60, the controller 100 controls the blade adjustment device such that the individual blade angles of the rotor blades 30 are cyclically adjusted with this amplitude determined in step S30 and, if necessary, reduced in step S55, and thus continue to support the wind tracking movement continued in step S60 by the tracking drive 20.

[0121] The process or control then returns to step S10.

[0122] In another version, which is Fig. 3 As shown, in a first step S110, the controller 100 uses the wind vane 10 to determine a deviation between a wind direction and the horizontal component of the rotor axis (oriented into the nacelle 120).

[0123] If this deviation exceeds a predetermined minimum value (S120: "Y"), the controller 100 determines that a wind yaw requirement exists and switches to a yaw operating mode; otherwise (S120: "N"), the method or control returns to step S110.

[0124] In the tracking mode, in step S130, it determines a setpoint for a rotor torque, for example based on a power requirement of the wind turbine or the like, a wind tracking direction of the rotor around the yaw axis (by "CW" ("ClockWise"), "CCW" ("CounterClockWise") in Fig. 1(indicated) as well as an amplitude of a blade pitch adjustment to support wind tracking by the tracking drive. This amplitude can, for example, be a stored, constant reference value or one read from a characteristic map.

[0125] If the yaw direction and the direction in which the rotor 130 attempts to rotate the nacelle 120 due to the tilt angle without blade angle adjustment to support a yaw movement by the yaw drive are opposite (S140: "Y"), a constant offset is added to this amplitude in step S145, and the control or method continues with step S150. This occurs in the CCW or counterclockwise direction for the most common rotors, which rotate rightward with the wind facing the rotor from the front, when yaw is required. Otherwise (S140: "N"), the control or method continues directly with step S150.Conversely, in a modification, the amplitude determined in step S130 can be reduced by a constant offset in a step S145 if the yaw direction and the direction in which the rotor 130 attempts to rotate the nacelle 120 without blade angle adjustment to support a yaw movement by the yaw drive are in the same direction or not in opposite directions. In an advantageous alternative embodiment, the offset is not constant but proportional to the setpoint for the rotor torque determined in step S130.

[0126] If the rotor torque or the (rotor) torque setpoint falls below a specified torque limit value (S150: "Y"), the controller sets the amplitude of the blade angle adjustment to support a wind yaw movement by the yaw drive to zero in a step S155 and continues with step S160; otherwise (S150: "N") the controller or the method continues directly with step S160.

[0127] In step S160, the controller 100 determines a lead angle to maintain a minimum blade angle based on the blade pitch adjustment amplitude determined in steps S130, S145, or S155, and adjusts the blade angles cyclically with the amplitude and additionally collectively by this lead angle. Furthermore, it controls the tracking drive 20 such that it rotates the nacelle 120 and thus the rotor 130 around the yaw axis G in such a way that the deviation is reduced.

[0128] In another version, which is Fig. 4 As shown, in a first step S210, the controller 100 uses the wind vane 10 to determine a deviation between a wind direction and the horizontal component of the rotor axis (oriented into the nacelle 120).

[0129] If this deviation exceeds a predetermined minimum value (S220: "Y"), the controller 100 determines that a wind tracking requirement exists and switches to a tracking operating mode; otherwise (S220: "N"), the method or control returns to step S210.

[0130] In tracking mode, in a step S230, it determines a rotor rotation frequency of the rotor 130 about its rotor axis R, a rotor (rotational) position, an amplitude of a blade angle adjustment to support a wind tracking movement by the tracking drive, and, based on the rotor rotation frequency, a phase shift of the amplitude relative to a rotor-fixed reference angular position, which it determines based on the rotor (rotational) position. The amplitude can, for example, be a stored, constant reference value or one read from a characteristic map.

[0131] In a step S240, the controller 100 adjusts the blade angles cyclically with the determined amplitude and phase shift.

[0132] If a predetermined waiting time has elapsed since the activation of this blade angle adjustment (S250: "Y"), it controls the tracking drive 20 in a step S260 so that it rotates the nacelle 120 and thus the rotor 130 about the yaw axis G in such a way that the deviation is reduced.

[0133] Although exemplary embodiments have been explained in the preceding description, it should be noted that a large number of modifications are possible.

[0134] Thus, the procedure or system of execution of the Fig. 2This is explained using a single-stage reduction when the (first) lower reduction speed limit is exceeded. In modifications not shown, one or more additional reduction and / or one or more increase stages can also be provided if one or more upper increase speed limits are exceeded.

[0135] The procedure or system of execution of the Fig. 3 comprises a determination of the amplitude of the blade angle adjustment both as a function of a rotor torque (cf. steps S150, S155) and a wind tracking direction of the rotor about the yaw axis (cf. steps S140, S145) as well as a lead angle as a function of the amplitude (cf. steps S160), wherein one or two of these features can be omitted in modifications not shown.

[0136] The procedure or system of execution of the Fig. 4has a waiting time (see step S250) as well as a dynamically adjusted commanded phase shift (see steps S230, S240), whereby one of these features can be omitted in modifications not shown.

[0137] Furthermore, it should be noted that the exemplary embodiments are merely examples and are not intended to limit the scope of protection, applications, or structure in any way. Rather, the preceding description provides the skilled person with a guide for implementing at least one exemplary embodiment, whereby various modifications, particularly with regard to the function and arrangement of the described components, may be made without departing from the scope of protection as defined by the claims.

[0138] In particular, individual aspects of the present invention, in particular the reduction or analog increase of the amplitude in a reducing or

[0139] Increase speed range (see especially Fig. 2 and associated description), the adjustment of the amplitude depending on a rotor torque or a yaw direction or the adjustment of the blade angle by the lead angle (see in particular Fig. 3 and associated description), and the activation of the tracking drive by a specified waiting time after the blade angle adjustment (delayed) or the commanded phase shift dynamically adjusted depending on a rotor rotation frequency (see in particular Fig. 4 and associated description), explained above using various embodiments, wherein two or more of these aspects or features or embodiments described above can also be advantageously combined.

[0140] For example, the above-explained reduction and / or increase in the amplitude in a reduction or increase speed range can be implemented in addition to the adjustment of the amplitude depending on a rotor torque and / or a yaw direction and / or the adjustment of the blade angle by the lead angle. Additionally or alternatively, the above-explained reduction and / or increase in the amplitude in a reduction or increase speed range can be implemented.

[0141] The increase in speed range can be implemented in addition to the activation of the tracking drive by a predetermined waiting time after the blade pitch adjustment and / or the commanded phase shift dynamically adjusted as a function of a rotor rotation frequency. Additionally or alternatively, for example, the above-described adjustment of the amplitude as a function of a rotor torque and / or a wind yaw direction and / or the adjustment of the blade angle by the lead angle can be implemented in addition to the activation of the tracking drive by a predetermined waiting time after the blade pitch adjustment and / or the commanded phase shift dynamically adjusted as a function of a rotor rotation frequency. List of reference symbols

[0142] 10Wind vane 20Tracking drive 30Rotor blade 100Control system 110Tower 120Nacelle 130Rotor 140Generator (gearbox unit) 150Power grid BBlade axis GGyaw axis RRotor axis

Claims

1. A method of operating a wind energy installation which comprises a rotor (130) that can rotate about a rotor axis (R), wherein the rotor (130) has at least two rotor blades (30) that can be individually adjusted about their blade axis (B), and a tracking drive (20) for tracking of the rotor about a yaw axis (G) according to the wind, wherein, in a tracking mode of operation, blade angles of the rotor blades are adjusted (S240) about their blade axes by the tracking drive in order to support a movement of tracking according to the wind, characterised in that a commanded phase shift of an amplitude of the adjustment of the blade angle with respect to a rotor-fixed reference angle position about the rotor axis is dynamically adjusted (S230) as a function of a rotor rotation frequency of the rotor about the rotor axis.

2. The method according to claim 1, characterised in that the tracking drive for tracking of the rotor about the yaw axis according to the wind is activated (S260) after a specified waiting time following the adjustment of the blade angle of the rotor blades about their blade axis in order to support this movement of tracking according to the wind; and the waiting time is specified as a function of a rotor rotation frequency, a wind speed and / or a torque of the rotor about the rotor axis.

3. The method according to any one of the preceding claims, characterised in that the tracking drive for tracking of the rotor about the yaw axis according to the wind is deactivated together with the adjustment of the blade angle of the rotor blades about their blade axis or by a predetermined lead time before this adjustment of the blade angle, in order to support this movement of tracking according to the wind.

4. The method according to any one of the preceding claims, characterised in that the waiting time is at least 0.25 seconds and / or at most 30 seconds.

5. The method according to any one of the preceding claims, characterised in that the commanded phase shift additionally has a static component that is independent of the rotor rotation frequency.

6. The method according to any one of the preceding claims, characterised in that the commanded phase shift has a first phase shift value for a first value of the rotor rotation frequency and a larger, second phase shift value for a larger, second value of the rotor rotation frequency.

7. The method according to any one of the preceding claims, comprising the steps of: - determining (S210) a requirement to carry out tracking according to the wind; - determining (S230) the amplitude of the blade angle adjustment for supporting the tracking movement according to the wind by the tracking drive; and - adjusting (S240) the individual blade angles of the rotor blades on the basis of this amplitude, wherein the method comprises the steps of: - determining (S230) a rotor rotation frequency; - determining (S230) a phase shift of the amplitude as a function of the rotor rotation frequency; and - adjusting (S240) the individual blade angles of the rotor blades on the basis of this phase shift; and / or the step of: - activating (S260) the tracking drive in order to track the rotor about the yaw axis according to the wind after a predetermined waiting time following activation of the blade angle adjustment of the rotor blades about their blade axis in order to support this movement of tracking according to the wind.

8. A system for operating a wind energy installation, which wind energy installation comprises a rotor (130) that can rotate about a rotor axis (R), wherein the rotor (130) has at least two rotor blades (30) that can be individually adjusted about their blade axis (B), and a tracking drive (20) for tracking of the rotor about a yaw axis (G) according to the wind, wherein the system is set up for carrying out the method according to any one of the preceding claims, and / or comprises: - means for adjusting blade angles of the rotor blades about their blade axis in order to support a movement of tracking according to the wind by the tracking drive in a tracking mode of operation, as well as - means for dynamically adjusting a commanded phase shift of an amplitude of this adjustment of the blade angle with respect to a rotor-fixed reference angle position about the rotor axis as a function of a rotor rotation frequency of the rotor about the rotor axis.

9. The method of operating a wind energy installation according to any one of the preceding claims 1 to 7, wherein an amplitude of this adjustment of the blade angle is adjusted (S145, S155) as a function of - a rotor torque about the rotor axis and / or - a wind tracking direction of the rotor about the yaw axis; and / or wherein - the blade angles are additionally adjusted (S160) by a lead angle in order to maintain a minimum blade angle as a function of an amplitude of this blade angle adjustment.

10. The method according to claim 9, characterised in that the amplitude of the blade angle adjustment in order to support a movement of tracking according to the wind by the tracking drive is zero in case the rotor torque falls below a predetermined torque limit value.

11. The method according to any one of the preceding claims 9 or 10, characterised in that the rotor torque is determined on the basis of a target value of the torque.

12. The method according to any one of the preceding claims 9 to 11, characterised in that the amplitude of the blade angle adjustment in order to support a movement of tracking according to the wind by the tracking drive in a first wind tracking direction and the amplitude of the blade angle adjustment in order to support a movement of tracking according to the wind by the tracking drive in a second wind tracking direction opposite to the first wind tracking direction has an offset, in particular a predetermined and / or constant offset or an offset which is dependent on a rotor torque.

13. The method according to any one of the preceding claims 9 to 12, characterised in that the blade angles are collectively adjusted by the lead angle.

14. The method according to any one of the preceding claims 9 to 13, characterised by the steps of: - determining (S110) a requirement to carry out tracking according to the wind; - determining (S130, S145, S155) the amplitude of the blade angle adjustment to support the movement of tracking according to the wind by the tracking drive; and - adjusting (S160) the individual blade angles of the rotor blades on the basis of this amplitude, wherein this amplitude is determined (S140 - S155) as a function of a rotor torque about the rotor axis and / or a wind tracking direction of the rotor about the yaw axis and / or the blade angles are adjusted (S160) as a function of a lead angle that has been determined in order to maintain a minimum blade angle.

15. The system according to claim 8, wherein the system is set up for carrying out the method according to any one of the preceding claims 9 to 14, and / or wherein the system comprises: - means for adjusting blade angles of the rotor blades about their blade axis in order to support a movement of tracking according to the wind by the tracking drive in a tracking mode of operation, as well as - means for adjusting an amplitude of this blade angle adjustment as a function of a rotor torque about the rotor axis and / or a wind tracking direction of the rotor about the yaw axis; and / or - means for adjusting the blade angles in order to maintain a minimum blade angle in addition to a lead angle as a function of an amplitude of this blade angle adjustment.

16. The method of operating a wind energy installation according to any one of the preceding claims 1 to 7, wherein an amplitude of the blade angle adjustment - is reduced (S55) by a predetermined value or is reduced (S55) to a predetermined value in case a yaw speed of the rotor about the yaw axis is within a predetermined reduction speed range, which has a lower reduction speed limit; and / or - is increased by a predetermined value or is increased to a predetermined value in case a yaw speed of the rotor about the yaw axis is within a predetermined increase speed range, which has an upper increase speed limit.

17. The method according to claim 16, characterised in that, in the tracking mode of operation, - at least one, in particular at least two, and / or at most four reduction speed ranges, in particular exactly one or two reduction speed ranges, are provided, for which the amplitude of the blade angle adjustment is reduced, in each case in a speed range-specific manner; and / or - at least one, in particular at least two, and / or at most four increase speed ranges, in particular exactly one or two increase speed ranges, are provided, for which the amplitude of the blade angle adjustment is increased, in each case in a speed range-specific manner.

18. The method according to any one of the preceding claims 16 or 17, characterised in that, in the tracking mode of operation, in order to support a movement of tracking according to the wind by the tracking drive, the amplitude of the blade angle adjustment - is reduced by a predetermined value or is reduced to a predetermined value in case the yaw speed is within a predetermined second reduction speed range, which has a second, lower reduction speed limit; and / or - is increased by a predetermined value or is increased to a predetermined value in case the yaw speed is within a predetermined second increase speed range, which has a second, upper increase speed limit.

19. The method according to any one of the preceding claims 16 to 18, characterised in that a speed range extends over at least 0.05° per second.

20. The method according to any one of the preceding claims 16 to 19, characterised by the steps of: - determining (S10) a requirement to carry out tracking according to the wind; - determining (S30) the amplitude of the blade angle adjustment in order to support the tracking movement according to the wind by the tracking drive; - adjusting (S40) the individual blade angles of the rotor blades on the basis of this amplitude; - determining (S40) an actual value of the yaw speed of the rotor about the yaw axis; - reducing (S55) the determined amplitude in a stepwise manner in case the actual value exceeds one or more specified speed limits; and / or increasing the determined amplitude in a stepwise manner in case the actual value falls below one or more specified speed limits; as well as - adjusting (S60) the individual blade angles of the rotor blades on the basis of this amplitude.

21. The system according to claim 8, wherein the system is set up for carrying out the method according to any one of the preceding claims 16 to 20, and / or wherein the system comprises: - means for adjusting blade angles of the rotor blades about their blade axis in order to support a movement of tracking according to the wind by the tracking drive in a tracking mode of operation, as well as - means for reducing an amplitude of this blade angle adjustment by a predetermined value or to a predetermined value in case a yaw speed of the rotor about the yaw axis is within a predetermined reduction speed range, which has a lower reduction speed limit; and / or - means for increasing an amplitude of this blade angle adjustment by a predetermined value or to a predetermined value in case a yaw speed of the rotor about the yaw axis is within a predetermined increase speed range, which has an upper increase speed limit.

22. A computer program product comprising a program code which is stored on a computer-readable medium, wherein execution of this program code causes a system or a control facility, in particular a computer, to carry out the method according to any one of claims 1 to 7, 9 to 14, or 16 to 20.