Control and operation of power converters

Abstract

A method of operating a wind turbine (1) having a generator (10) and a power converter (60). The method can include determining a reduced first power setpoint (94) in response to an operating condition; reducing active power from a line side converter (66) to a grid (80) in accordance with the reduced first power setpoint (94); determining a reduced power setpoint (92) for a machine side converter (62); reducing torque applied by the machine side converter (62) to the generator (10) such that active power is generated by the generator (10) in accordance with the reduced second power setpoint (92); and dissipating excess power in one or more resistive elements (68) as long as the second power setpoint is higher than the first power setpoint. A wind turbine configured for such a method is also provided.

Description

Technical Field

[0001] This disclosure relates to methods for operating power converters (and particularly power converters connected to wind turbines). This disclosure also relates to methods for operating wind turbines. Furthermore, this disclosure relates to wind turbines including generators connected to the power converters. Background Technology

[0002] Modern wind turbines are commonly used to supply electricity to the power grid. These turbines generally consist of a tower and a rotor mounted on the tower. The rotor (typically including a hub and multiple blades) rotates under the influence of wind on the blades. This rotation generates torque, which is typically transmitted to a generator either directly through the rotor shaft (“direct drive”) or via a gearbox. The generator then produces electricity that can be supplied to the power grid.

[0003] Generators can be connected to the power grid via power converters. Such power converters may include a line-side converter connected to the power grid, a machine-side converter connected to the generator's rotor, and a DC link between the line-side converter and the machine-side converter.

[0004] The power converter regulates the power output from the generator to the grid and controls the torque applied to the generator stator. During normal operation of a wind turbine, the active power generated by the generator is injected into the grid. The power that can be generated by the generator depends on the prevailing wind speed and the torque applied to the generator stator. The control of the wind turbine will largely depend on the prevailing wind speed and will largely select the blade pitch angle and the torque applied to the stator to maximize the electrical power generated and injected into the grid.

[0005] However, anomalies can occur on the power grid in certain situations, such as high frequencies. According to some power grid specifications, wind turbines should be able to reduce the active power output from generators to the grid. For example, power grid specifications may specify the ability to reduce active power output by 25% per second. Other power grid conditions may also occur where there are no anomalies (not yet present) but a reduction in active power from wind turbines or wind farms is required.

[0006] This disclosure relates to methods and systems designed to cope with such grid conditions. This disclosure also relates to methods for operation when wind turbines are shut down. Summary of the Invention

[0007] In one aspect, a method for operating a wind turbine is provided, the wind turbine having a generator and a power converter. The method includes: determining a reduced first power setpoint in response to operating conditions; and reducing active power from the line-side converter to the grid according to the reduced first power setpoint. The method further includes: determining a reduced second power setpoint for the machine-side converter; and reducing the torque applied to the generator by the machine-side converter such that the generator generates active power according to the reduced second power setpoint. The method also includes: dissipating excess power in one or more resistive elements whenever the second power setpoint is higher than the first power setpoint.

[0008] Based on this aspect, a different power setpoint is provided for the line-side converter than for the machine-side converter. The power setpoint for the line-side converter can be selected to, for example, conform to grid requirements at a given time. A different power setpoint can be selected for the machine-side converter. The difference between the two setpoints can be allowed to avoid operational problems with the generator or the (wind) turbine connected to it.

[0009] Technical Solution 1. A method for operating a wind turbine (1), the wind turbine (1) having a generator (10) and a power converter (60), the method comprising:

[0010] The first power setpoint (94) is determined in response to the operating conditions;

[0011] The active power from the line-side converter (66) to the grid (80) is reduced according to the reduced first power setpoint (94);

[0012] Determine the reduced power setpoint (92) for the machine-side converter (62);

[0013] Reduce the torque applied to the generator (10) by the machine-side converter (62) so that the generator (10) generates active power according to the reduced second power setpoint (92); and

[0014] As long as the second power setpoint is higher than the first power setpoint, excess power is dissipated in one or more resistive elements (68).

[0015] Technical Solution 2. The method according to Technical Solution 1, wherein the operating condition is the condition of the power grid.

[0016] Technical Solution 3. The method according to Technical Solution 2, wherein the operating state of the power grid is an increase in the frequency of the power grid.

[0017] Technical Solution 4. The method according to Technical Solution 2, wherein the operating condition of the power grid is a voltage drop.

[0018] Technical Solution 5. The method according to any one of Technical Solutions 1-4, wherein the reduced second power setpoint (92) is reduced according to the maximum reduction rate.

[0019] Technical Solution 6. The method according to Technical Solution 5, wherein the maximum reduction rate is determined to avoid overspeed of the rotor (5) of the wind turbine (1).

[0020] Technical Solution 7. The method according to any one of Technical Solutions 1-6, wherein the reduced first power setpoint (94) is received by the wind turbine (1) from the grid operator.

[0021] Technical Solution 8. The method according to any one of Technical Solutions 1-6, wherein the reduced first power setpoint (94) is determined by the wind turbine (1) in response to measured grid variables.

[0022] Technical Solution 9. The method according to any one of Technical Solutions 1-8, wherein the method further includes: pitching the blades (7) of the wind turbine rotor (5) to reduce the rotational speed of the wind turbine rotor (5).

[0023] Technical Solution 10. The method according to any one of technical solutions 1-9, wherein the method further comprises: monitoring the operation of the resistive element (68) to prevent the resistive element (68) from reaching its operating limit, and

[0024] If one or more of the resistive elements (68) reach their operating limits, less energy is dissipated in the resistive elements (68).

[0025] Technical Solution 11. The method according to any one of technical solutions 1-10, wherein the method further includes: increasing power output once the condition of the power grid (80) is resolved.

[0026] Technical Solution 12. A wind turbine (1), the wind turbine (1) comprising:

[0027] A wind turbine rotor (5) having multiple blades (7),

[0028] A generator (10) is operatively connected to the wind turbine rotor (5).

[0029] A power converter (60) electrically connects the generator (10) to the power grid (80), wherein the power converter (60) includes a line-side converter (66), a machine-side converter (62), and a DC link (64), and

[0030] Controller (90), in which

[0031] The controller (90) is configured to determine a first power setpoint (94) in response to grid conditions and send the first power setpoint (94) to the line-side converter (66), and to determine a second power setpoint (92) in response to the grid conditions and send the second power setpoint (92) to the machine-side converter (62), wherein

[0032] The second power setpoint (92) is higher than the first power setpoint (94).

[0033] Technical Solution 13. The wind turbine according to Technical Solution 12, wherein the wind turbine further includes one or more resistive elements (68) in the DC link (64), and wherein the power converter (60) is configured to dissipate excess power from the generator (10) in the resistive elements (68).

[0034] Technical Solution 14. The wind turbine according to Technical Solution 12 or 13, wherein the controller is configured to reduce the second power setpoint (92) as quickly as possible.

[0035] Technical Solution 15. The wind turbine according to any one of technical solutions 12-14, wherein the generator (10) is a permanent magnet generator and the power converter is a full power converter. Attached Figure Description

[0036] The following description will use the accompanying drawings to illustrate non-limiting examples of the present disclosure, in which:

[0037] Figure 1 A perspective view of a wind turbine as an example according to this disclosure is shown;

[0038] Figure 2 A simplified interior view of the nacelle of a wind turbine, as shown in one example according to this disclosure;

[0039] Figure 3 The diagram schematically illustrates a method for operating a wind turbine and a power converter according to an example of the prior art;

[0040] Figure 4 The method of operating a wind turbine and a power converter according to an example of this disclosure is schematically illustrated;

[0041] Figure 5 The following schematically illustrates a method for operating a wind turbine and power converter under grid disturbance conditions, according to an example of this disclosure; and

[0042] Figure 6 The method of operating a power converter according to another example is illustrated schematically. Detailed Implementation

[0043] In these figures, the same reference symbols are used to denote matching elements.

[0044] Figure 1 A perspective view of an example wind turbine 1 is shown. As shown, the wind turbine 1 includes a tower 2 extending from a support surface 3, a nacelle 4 mounted on the tower 2, and a rotor 5 coupled to the nacelle 4 in a front region. The rotor 5 includes a rotatable hub 6 and at least one rotor blade 7 coupled to and extending outward from the hub 6. For example, in the example shown, the rotor 5 includes three rotor blades 7. However, in alternative embodiments, the rotor 5 may include more or fewer than three rotor blades 7. Each rotor blade 7 may be spaced from the hub 6 to allow rotation of the rotor 5 to convert kinetic energy from wind into usable mechanical energy, and subsequently into electrical energy. For example, the hub 6 may be rotatably coupled to a generator 10 located within or forming part of the nacelle 4. Figure 2 This allows for the generation of electrical energy. The rotation of the rotor can be transmitted directly (e.g., in a direct-drive wind turbine) to the generator or transmitted to the generator via a gearbox.

[0045] Figure 2 Show Figure 1 A simplified internal view of an example of the nacelle 4 of a wind turbine 1. As shown, a generator 10 may be disposed within the nacelle 4. Generally, the generator 10 may be coupled to the rotor 5 of the wind turbine 1 to generate electrical power from the rotational energy generated by the rotor 5. For example, the rotor 5 may include a main rotor shaft 8 coupled to a hub 6 for rotation therewith. The generator 10 may then be coupled to the rotor shaft 8 such that rotation of the rotor shaft 8 drives the generator 10. For example, in the illustrated embodiment, the generator 10 includes a generator shaft 11 rotatably coupled to the rotor shaft 8 via a gearbox 9. In an alternative example, the hub may be directly coupled to the rotor of the generator, and rotation of the hub may therefore drive the rotor of the generator.

[0046] Generator 10 can be electrically connected to the converter. The wind turbine converter allows the generator's output power to be adapted to the grid's requirements.

[0047] It should be understood that the rotor shaft 8, gearbox 9 and generator 10 are generally supported in the nacelle 4 by the base plate or support frame 12 positioned on top of the wind turbine tower 2.

[0048] The nacelle 4 is rotatably connected to the tower 2 via a yaw system 20. The yaw system includes a yaw bearing ( Figure 2(Not visible in the image), the yaw bearing has two bearing members configured to rotate relative to the other. The tower 2 is connected to one of the bearing members, and the floor plate or support frame 12 of the nacelle 4 is connected to the other bearing member. The yaw system 20 includes a ring gear 21 and multiple yaw actuators 22, each with a motor 23, a gearbox 24, and a pinion 25 for meshing with the ring gear to rotate one of the bearing members relative to the other.

[0049] The nacelle 4 also includes a shroud structure 50 that houses the wind turbine components. In this example, the wind turbine components housed in or surrounded by the shroud structure 50 include a generator 10, a converter, a gearbox 9, and a shaft 8. In other examples, the wind turbine components arranged within the nacelle may refer to the converter and the generator.

[0050] Figure 3 This schematically illustrates a method for operating a wind turbine and power converter according to an example of prior art. Figure 3 In this example, the wind turbine includes a generator 10, which is connected to the power grid 80 via a power converter 60. In this particular example, the generator 10 is a permanent magnet generator, including a generator rotor carrying multiple permanent magnets. The permanent magnet generator can be directly driven by the wind turbine rotor 5 (i.e., without a gearbox). In this example, the wind turbine can be an offshore wind turbine. In this particular example, the stator of the generator 10 is connected to a machine-side converter 62. The machine-side converter is connected to a line-side converter 66 via a DC link 64.

[0051] Generator 10 is configured to convert mechanical energy into electrical energy with AC voltage and current, and to supply the generated AC to machine-side converter 62. Due to varying wind conditions, the AC from the generator has a variable frequency. Machine-side converter 62 is configured to convert or rectify the AC into DC voltage and current, which is delivered to DC link 64. Line-side converter 66 converts the DC on DC link 64 into fixed-frequency AC for use with power grid 80. Line-side converter 66 can be connected to power grid 80 via main transformer 70.

[0052] According to this example, the power converter 60 receives a single setpoint 92 from the wind turbine controller 90. The setpoint 92 is based on the optimal operation of the wind turbine according to primary weather conditions. The generator's rotational speed can be controlled by controlling the generator torque. The generator's rotational speed, in turn, determines the rotational speed of the wind turbine rotor 5. The rotational speed can be selected according to a predefined operating schedule. Specifically, it is known to control the wind turbine differently within different wind speed ranges. In the wind speed range below the rated wind speed, the rotational speed can be selected such that the wind impacts the rotor blades at an optimal angle of attack. This operating method can be maintained until the maximum rotational speed is reached.

[0053] At higher wind speeds (especially above rated wind speed), the rotational speed can be controlled to maintain a constant speed. Maximum torque can be applied to the stator, and the blades can be pitched to ensure a constant rotational speed. Variations of this optimized operation are possible.

[0054] According to predefined operations, setpoint 92 can be sent from the wind turbine controller to the machine-side converter. The resulting active power output 100 is fed into the power grid. The wind turbine controller 90 can be a local wind turbine controller, or it can be a controller for, for example, a wind farm.

[0055] Figure 4 The method of operating a wind turbine and power converter according to an example of this disclosure is schematically illustrated. (As in...) Figure 3 In the example, the wind turbine may include a permanent magnet generator 10, which has a rotor carrying multiple magnets. (As in...) Figure 3 In the example, the generator can be connected to the power grid 80 via power converter 60.

[0056] The power converter may include a line-side converter 66, a machine-side converter 62, and a DC link 64. The wind turbine may also include a controller 90, configured to determine a first power setpoint 94 in response to, for example, grid conditions and transmit the first power setpoint 94 to the line-side converter 66, and to determine a second power setpoint 92 in response to grid conditions and transmit the second power setpoint 92 to the machine-side converter 62. The second power setpoint 92 may be higher than the first power setpoint 94.

[0057] According to the second setpoint, the generator 10 may have a power output 100. However, according to the first setpoint, a certain amount of active power 104 may be fed into the power grid.

[0058] The wind turbine may also include one or more resistive elements in the DC link, and the power converter may be configured to dissipate excess power from the generator in the resistive elements. The DC link may include a DC chopper to dissipate excess power from the generator that cannot be absorbed by the grid. When needed, a switch in the DC chopper may be turned off to divert current through the chopper.

[0059] The operation of the DC chopper is indirectly controlled by the power supplied by the machine-side converter on one hand and the power supplied to the grid by the line-side converter on the other. Unlike the prior art, the setpoint is a power setpoint, which typically has a setpoint for the voltage at the DC link and operates the chopper according to the voltage at the DC link.

[0060] Operation based on individual power setpoints allows converters and wind turbines to reliably cope with different conditions, including various grid anomalies.

[0061] According to this example, a method for operating a wind turbine can be provided. The method includes: determining a reduced first power setpoint 94 in response to operating conditions; reducing active power 104 from a line-side converter 66 to a power grid 80 based on the reduced first power setpoint 94; determining a reduced power setpoint for a machine-side converter; and reducing the torque applied to a generator 10 by the machine-side converter 62 such that active power is generated by the generator based on a reduced second power setpoint 92. The method further includes: dissipating excess power (100-104) in one or more resistive elements 68 whenever the second power setpoint is higher than the first power setpoint.

[0062] The operating condition can be a grid condition, which can be an abnormal grid condition. The grid condition can be a grid frequency higher than a predetermined threshold. The frequency on the grid can be controlled by the amount of active power supplied to the grid. In response to high frequencies, the wind turbine may need to reduce the active power output to the grid. Such a response can be limited by grid specifications. According to existing technology, the generator torque can be reduced. If the generator torque is reduced, the speed of rotor 5 will tend to increase. This can be offset by a braking system and / or by pitching the blades to reduce the converted aerodynamic energy. Depending on the wind turbine, and according to grid disturbances and grid specifications, such actions may not be sufficient to reduce the active power output.

[0063] According to the examples disclosed herein, a first rated power setpoint 94 is sent to a line-side converter 66. The line-side converter 66 receives the first setpoint and injects active power 104 into the grid based on this (reduced) setpoint 94. Simultaneously, a second setpoint 92 is sent to a machine-side converter 62. In some examples, the reduced second power setpoint 92 is reduced according to a maximum reduction rate. And in some examples, the maximum reduction rate may be determined to avoid overspeeding of the wind turbine rotor 5. In other examples, the maximum reduction rate may be determined to avoid loads exceeding acceptable levels.

[0064] The controller 90 can measure electrical variables at the power grid (e.g., voltage, frequency, phase angle, etc.) and automatically determine the power grid condition or anomaly. The wind turbine controller can calculate or otherwise determine a suitable setpoint reduction signal. In other cases, the controller 90 can receive a setpoint reduction signal 98 from the power grid. The power grid condition may be a particularly high frequency. Another condition may be a voltage anomaly.

[0065] By implementing this control, wind turbines can be made compliant with grid regulations. In other cases, the control can be used to reduce the load on the wind turbine.

[0066] In some examples, the reduced first power setpoint may be received by the wind turbine from the grid operator. In other examples, the reduced first power setpoint may be determined by the wind turbine or its controller. Specifically, the wind turbine may measure the grid frequency and determine an appropriate response. In still other examples, the wind turbine may receive the measured grid frequency from another entity, such as the grid operator or wind farm controller.

[0067] In another example, a power grid condition or anomaly can be a voltage dip. A voltage dip, or "voltage sag," is a sudden increase in the mains voltage. The voltage during such a dip can drop to, for example, 90% or less of the rated voltage. Specifically, during a voltage dip, the voltage on the grid can decrease to 30%, 20%, or 10% of the rated voltage, and may even reach 0V. The duration of a voltage dip can be very short, but can last for several seconds.

[0068] Grid specifications may stipulate that wind turbines must remain connected to the grid under these conditions. Similarly, first and second power setpoints can be generated for the machine-side and line-side converters. Excess power can be dissipated in resistive elements (such as choppers in a DC link).

[0069] In yet another example, the operating condition could be that the wind turbines need to be shut down or are planned to be shut down. When operation is to be interrupted, first and second power setpoints can be generated in a similar manner to before. In this case, the setpoints for the line-side converters are not necessarily specified by grid regulations.

[0070] In some examples, while reducing the generator torque, the method may also include pitching the blades of the wind turbine rotor to reduce the rotational speed of the wind turbine rotor. As the rotational speed of the wind turbine rotor decreases, the second reduced power setpoint 92 may be further reduced. Excess electrical energy may still be dissipated in the resistive elements. The second reduced power setpoint 92 may be reduced as needed until the active power generated by the generator 100 can be fed into the grid 80. Until this condition is reached, excess electrical energy can be consumed in the resistors.

[0071] In some examples, the method may also include monitoring the operation of the resistive elements to prevent them from reaching their operating limits. For example, the method may include measuring the temperature of one or more resistive elements (e.g., in a DC chopper). The temperature in the resistive elements can be measured to ensure they have not reached a critical temperature at which they may fail. Alternatively, the cumulative amount of energy dissipated in the resistive elements can be monitored or calculated. Based on the amount of energy dissipated, the extent to which the resistive elements are approaching their operating limits can be calculated or estimated.

[0072] In some examples, the method may also include dissipating less energy if one or more of the resistive elements reach one of their operating limits. For example, less energy may be dissipated in the resistive elements if the temperature of the resistive element exceeds a threshold, if the actuation time of the resistive element exceeds a time threshold, or if the amount of energy dissipated reaches a predetermined level. In some cases, this may mean that more active power needs to be delivered to the grid than is expected or specified by grid regulations. This can be achieved to avoid converter or wind turbine trips.

[0073] In some examples, the method may also include increasing power output once the grid condition is resolved. Once the grid condition is resolved, the wind turbine can be operated again to optimize power output. In these conditions, the control of the power converter can switch back to normal operation, in which a single setpoint is sent to the power converter to determine the generator torque.

[0074] In some examples, the method may also include ensuring that the rotor speed of the wind turbine does not drop below a threshold at which the wind turbine becomes difficult to control. If necessary, the power output can be increased to ensure a minimum rotor speed.

[0075] In this particular example, the generator is a permanent magnet generator, and the power converter is a full-power converter. In this particular example, the wind turbine may be an offshore, directly driven wind turbine. In another example ( Figure 6 In this system, the generator can be a doubly fed induction generator (DFIG), and the transmission system can include a gearbox.

[0076] Figure 5 The following diagram schematically illustrates a method for operating a power converter in the event of grid disturbance, according to an example of this disclosure. In particular, the power converter may be connected to a generator driving a turbine, especially a generator driven by a wind turbine.

[0077] A method for operating a power converter connected to a power grid is shown. The power converter includes a machine-side converter, a DC link, and a line-side converter. The method includes: determining a grid anomaly; determining a first setpoint for the active power output of the line-side converter based on the grid anomaly; and determining a second setpoint for the active power output of the rotor-side converter, wherein the second setpoint differs from the first setpoint.

[0078] During the first part (left side of the diagram), the converter operates normally. There are no specific grid anomalies or conditions requiring a reduction in active power. In these cases, the only commands received by the power converter are those related to the machine-side converter. In this particular example, the rated power P can be generated. nom In the case of offshore wind turbines, P nomIt can be, for example, 6MW, 10MW or 12MW.

[0079] When a frequency increase occurs on the grid at t0, two setpoints P1 and P2 can be sent. This activates a "frequency control mode." In this mode, a first setpoint P1 for the grid-side converter and a second setpoint P2 for the machine-side converter are determined (e.g., calculated) separately. As shown in the diagram, the setpoint P1 for the grid-side converter can be rapidly reduced to adapt to grid conditions. The second setpoint P2 cannot be rapidly reduced because it could lead to unsafe conditions for the wind turbine or high loads due to overspeed of the wind turbine rotor. The slope of the second setpoint can be as high as possible to avoid such problems. In one example, the slope could be, for example, 0.4 MW / s. In contrast, the slope for reducing P1 can be, for example, two to four times higher, and the reduced power output can be achieved at t1.

[0080] As can be seen from the diagram, energy needs to be dissipated whenever the second power setpoint P2 is higher than the first setpoint P1 (up to t2). This can be achieved by passing current through one or more resistors in the DC link.

[0081] At t2, the second setpoint equals the first setpoint. This means that the power output from the generator is injected into the grid without dissipating additional electrical energy. The power P generated by the generator... red It is smaller than the normal operating value before the power grid anomaly.

[0082] At t=t3, the grid condition still exists, but the frequency increase is smaller than it was at the beginning of the grid condition. Therefore, the first setpoint P1 of the machine-side converter can be increased, and the second setpoint P2 can also be increased simultaneously. Thus, the power output can be increased without dissipating energy in the resistor.

[0083] At t=t4, the power grid returns to normal. Frequency control mode can be disabled and normal operation can be resumed. The first setpoint for the grid-side converter is no longer sent to the converter. The machine-side converter is controlled to gradually increase power output to return to normal at t5.

[0084] Figure 6 A method for operating a power converter 60 according to another example is illustrated schematically.

[0085] In this particular example (similar to) Figure 4In this arrangement, the wind turbine includes a wind turbine rotor 5 with multiple blades, a generator 10 operatively connected to the wind turbine rotor 5, and a power converter 60 electrically connecting the generator 10 to a power grid 80. The power converter 60 includes a line-side converter 66, a machine-side converter 62, and a DC link 64. In this example, the wind turbine also includes a controller 90. The controller is configured to determine a first power setpoint 94 in response to grid conditions and send the first power setpoint 94 to the line-side converter 66, and to determine a second power setpoint 92 in response to grid conditions and send the second power setpoint 92 to the machine-side converter 62, wherein the second power setpoint 92 is higher than the first power setpoint 94.

[0086] exist Figure 6 In this particular example, generator 10 may be a doubly-fed induction generator (DFIG). Generator 10 may be driven by gearbox 9. In this particular arrangement of the generator, machine-side converter 62 is electrically connected to the generator rotor. The generator stator is directly connected to the power grid. As used herein, "directly" means that there is no converter between the stator and the power grid. Depending on the circumstances, a transformer may be arranged between the power grid 80 and the stator.

[0087] The operation of wind turbines and converters can be largely the same as before. Figure 4 and Figure 5 The description is the same. (Similar to) Figure 6 In contrast to the DFIG configuration, this operating method is more efficient in configurations with permanent magnet generators and full-power converters, since all electrical power passes through the converter.

[0088] This written description uses examples to disclose the invention (including preferred embodiments) and also enables any person skilled in the art to implement the invention, including making and using any apparatus or system and performing any combined methods. The patentable scope of the invention is defined by the claims and may include other examples that would occur to a person skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements with non-substantial differences from the literal language of the claims. Aspects from the various embodiments described, and other known equivalents for each such aspect, may be mixed and matched by a person skilled in the art to construct additional embodiments and techniques in accordance with the principles of this application. If reference symbols associated with figures are placed in brackets in the claims, they are only used to attempt to increase the comprehensibility of the claims and should not be construed as limiting the scope of the claims.

Claims

1. A method of operating a wind turbine (1), the wind turbine (1) having a generator (10) and a power converter (60), wherein the power converter (60) includes a line-side converter (66), a machine-side converter (62), and a DC link (64), the method comprising: The first power setpoint (94) is determined in response to the operating conditions; The active power from the line-side converter (66) to the grid (80) is reduced according to the reduced first power setpoint (94); At the same time, a reduced second power setpoint (92) for the machine-side converter (62) is determined; Reduce the torque applied to the generator (10) by the machine-side converter (62) so that the generator (10) generates active power according to the reduced second power setpoint (92); and As long as the second power setpoint is higher than the first power setpoint, excess power is dissipated in one or more resistive elements (68).

2. The method according to claim 1, characterized in that, The operating condition refers to the condition of the power grid.

3. The method according to claim 2, characterized in that, The operating condition of the power grid is an increase in the frequency of the power grid.

4. The method according to claim 2, characterized in that, The power grid is operating under conditions of voltage dips.

5. The method according to any one of claims 1-4, characterized in that, The reduced second power setpoint (92) is reduced according to the maximum reduction rate.

6. The method according to claim 5, characterized in that, The maximum reduction rate is determined to avoid overspeed of the rotor (5) of the wind turbine (1).

7. The method according to any one of claims 1-4, characterized in that, The reduced first power setpoint (94) is received by the wind turbine (1) from the grid operator.

8. The method according to any one of claims 1-4, characterized in that, The reduced first power setpoint (94) is determined by the wind turbine (1) in response to the measured grid variables.

9. The method according to any one of claims 1-4, characterized in that, The method further includes: pitching the blades (7) of the wind turbine rotor (5) to reduce the rotational speed of the wind turbine rotor (5).

10. The method according to any one of claims 1-4, characterized in that, The method further includes: monitoring the operation of the resistive element (68) to prevent the resistive element (68) from reaching its operating limit, and If one or more of the resistive elements (68) reach their operating limits, less energy is dissipated in the resistive elements (68).

11. The method according to any one of claims 1-4, characterized in that, The method further includes increasing power output once the condition of the power grid (80) is resolved.

12. A wind turbine (1), the wind turbine (1) comprising: A wind turbine rotor (5) having multiple blades (7), A generator (10) is operatively connected to the wind turbine rotor (5). A power converter (60) electrically connects the generator (10) to the power grid (80), wherein the power converter (60) includes a line-side converter (66), a machine-side converter (62), and a DC link (64), and Controller (90), wherein The controller (90) is configured to determine a first power setpoint (94) in response to grid conditions and send the first power setpoint (94) to the line-side converter (66), and simultaneously determine a second power setpoint (92) in response to the grid conditions and send the second power setpoint (92) to the machine-side converter (62), wherein The second power setpoint (92) is higher than the first power setpoint (94).

13. The wind turbine according to claim 12, characterized in that, The wind turbine also includes one or more resistive elements (68) in the DC link (64), wherein the power converter (60) is configured to dissipate excess power from the generator (10) in the resistive elements (68).

14. The wind turbine according to claim 12 or 13, characterized in that, The controller is configured to lower the second power setpoint (92) as quickly as possible.

15. The wind turbine according to claim 12 or 13, characterized in that, The generator (10) is a permanent magnet generator, and the power converter is a full power converter.

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