Wind generating set and control method and control device thereof

Abstract

The invention provides a wind generating set and a control method and device thereof. The wind generating set comprises a first switch connected between a stator loop of the wind generating set and a power grid. The control method comprises the steps that the cut-in wind speed of the wind generating set is obtained; the current-moment wind speed and the previous-moment wind speed of the position where the wind generating set is located are obtained; in response to the wind speed at the current moment, the wind speed at the previous moment and the cut-in wind speed meeting the first condition or the second condition, the on-off state of the first switch is kept unchanged within the preset time period; wherein the first condition is that the wind speed at the previous moment is greater than the cut-in wind speed, and the wind speed at the current moment is not less than the difference between the cut-in wind speed and a predetermined first lag control value and is not greater than the cut-in wind speed; the second condition is that the wind speed at the previous moment is smaller than the cut-in wind speed, and the wind speed at the current moment is not smaller than the cut-in wind speed and not larger than the sum of the cut-in wind speed and the first lag control value.

Description

Technical Field

[0001] The present disclosure generally relates to the field of wind power, and more specifically, to a wind turbine generator set and a control method and a control device thereof. Background Art

[0002] When a wind turbine (referred to as a wind turbine, unit, etc.) is in operation, when the wind speed is lower than the grid-connected wind speed (cut-in wind speed), the stator circuit switch device is disconnected and the wind turbine is shut down; when the wind speed is higher than the grid-connected wind speed, the stator circuit switch device is closed, the wind turbine starts and runs, and power transmission is realized.

[0003] However, when the wind turbine generator set is at the grid-connected wind speed for a long time, the stator circuit switch device of the wind turbine generator set will frequently be in the switching state of closing (connecting) and opening (disconnecting), which will affect the life of the stator switch device and have an adverse effect on the reliability of the wind turbine generator set during its entire life cycle. However, the existing control scheme of the wind turbine generator set has the following shortcomings:

[0004] 1) When a wind turbine is at a speed close to the grid for a long period of time, the number of times the stator circuit switch devices operate will increase, affecting the reliability of the wind turbine throughout its life cycle.

[0005] 2) In order to ensure the reliability of the wind turbine throughout its life cycle, the stator circuit often uses switching devices that can withstand a higher number of operations, which increases the cost of the wind turbine. Summary of the invention

[0006] One of the objects of exemplary embodiments of the present disclosure is to overcome at least one of the above-mentioned technical problems.

[0007] One of the objectives of the exemplary embodiments of the present disclosure is to provide a control method to avoid frequent switching of switches of a wind turbine generator set.

[0008] According to a first aspect of the present disclosure, a control method for a wind turbine generator set is provided, the wind turbine generator set comprising a first switch connected between a stator circuit of the wind turbine generator set and a power grid, the control method comprising: obtaining a cut-in wind speed of the wind turbine generator set; obtaining a wind speed at a current moment and a wind speed at a previous moment at a location where the wind turbine generator set is located; in response to the wind speed at a current moment, the wind speed at a previous moment and the cut-in wind speed satisfying a first condition or satisfying a second condition, maintaining the on-off state of the first switch unchanged within a preset time period; wherein the first condition refers to: the wind speed at a previous moment is greater than the cut-in wind speed, and the wind speed at a current moment is not less than the difference between the cut-in wind speed and a predetermined first hysteresis control value and is not greater than the cut-in wind speed; the second condition refers to: the wind speed at a previous moment is less than the cut-in wind speed, and the wind speed at a current moment is not less than the cut-in wind speed and is not greater than the sum of the cut-in wind speed and the first hysteresis control value.

[0009] According to an embodiment of the present disclosure, the control method may further include: in response to the wind speed at a previous moment and the wind speed at a current moment both satisfying a first condition, or the wind speed at a previous moment and the wind speed at a current moment both satisfying a second condition, judging whether the rotational speed of the wind turbine generator set is less than a preset rotational speed; in response to the rotational speed of the wind turbine generator set being less than a preset rotational speed, controlling the wind turbine generator set to operate at a preset rotational speed and controlling the first switch to close.

[0010] According to an embodiment of the present disclosure, the preset rotation speed may be determined based on a limit value of a machine-side voltage of the wind turbine generator set and an open-circuit voltage of a generator of the wind turbine generator set.

[0011] According to an embodiment of the present disclosure, the step of controlling the wind turbine generator set to operate at a preset speed may include: controlling the torque and / or pitch angle of the wind turbine generator set to enable the wind turbine generator set to operate at the preset speed.

[0012] According to an embodiment of the present disclosure, in response to the wind speed at the previous moment and the wind speed at the current moment both satisfying the first condition or the second condition, and the rotational speed of the wind turbine generator set is greater than or equal to the preset rotational speed, the first switch can be controlled to close and the wind turbine generator set can be controlled to operate in a preset power generation mode.

[0013] According to an embodiment of the present disclosure, the control method may further include: in response to the wind speed at the previous moment and the wind speed at the current moment being greater than the sum of the cut-in wind speed and the first hysteresis control value, controlling the first switch to close and controlling the wind turbine generator set to operate according to a preset power generation mode.

[0014] According to an embodiment of the present disclosure, the control method may further include: in response to the wind speed at a previous moment and the wind speed at a current moment being less than the difference between the cut-in wind speed and the first hysteresis control value, controlling the wind turbine generator set to shut down and controlling the first switch to open.

[0015] According to an embodiment of the present disclosure, the control method may further include: obtaining the cut-out wind speed of the wind turbine generator set; in response to the wind speed at a previous moment, the wind speed at a current moment and the cut-out wind speed satisfying a third condition or satisfying a fourth condition, maintaining the on-off state of the first switch unchanged within a preset time period; wherein the third condition includes: the wind speed at a previous moment is greater than the cut-out wind speed, and the wind speed at a current moment is not less than the difference between the cut-out wind speed and a predetermined second hysteresis control value and is not greater than the cut-out wind speed; the fourth condition includes: the wind speed at a previous moment is less than the cut-out wind speed, and the wind speed at a current moment is not less than the cut-out wind speed and is not greater than the sum of the cut-out wind speed and the second hysteresis control value.

[0016] According to an embodiment of the present disclosure, the cut-in wind speed may be an initial minimum grid-connected wind speed determined according to the airfoil and tip speed ratio of the blades of the wind turbine generator set.

[0017] According to a second aspect of the present disclosure, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a program or code, and when the program or code is executed by a processor, the processor is prompted to execute the control method of the wind turbine generator set.

[0018] According to a third aspect of the present disclosure, a control device for a wind turbine generator set is provided, the wind turbine generator set comprising a first switch connected between a stator circuit of the wind turbine generator set and a power grid, the control device comprising: a cut-in wind speed acquisition unit, for acquiring a cut-in wind speed of the wind turbine generator set; a wind speed acquisition unit, for acquiring a current wind speed and a previous wind speed at a location where the wind turbine generator set is located; a control unit, for maintaining an on-off state of the first switch unchanged within a preset time period in response to the current wind speed, the previous wind speed and the cut-in wind speed satisfying a first condition or satisfying a second condition; wherein the first condition refers to: the wind speed at the previous moment is greater than the cut-in wind speed, and the wind speed at the current moment is not less than the difference between the cut-in wind speed and a predetermined first hysteresis control value and is not greater than the cut-in wind speed; the second condition refers to: the wind speed at the previous moment is less than the cut-in wind speed, and the wind speed at the current moment is not less than the cut-in wind speed and is not greater than the sum of the cut-in wind speed and the first hysteresis control value.

[0019] According to a fourth aspect of the present disclosure, a controller of a wind turbine generator set is provided, the controller comprising a memory and a processor, the memory storing a program or code, and when the program or code is executed by the processor, the processor is prompted to execute the above control method of the wind turbine generator set.

[0020] According to a fifth aspect of the present disclosure, a wind turbine generator set is provided, the wind turbine generator set comprising a first switch connected between a stator circuit of the wind turbine generator set and a power grid, and the above-mentioned control device or the above-mentioned controller.

[0021] The control method and control device according to the embodiments of the present disclosure can perform hysteresis control according to the grid-connected wind speed, thereby improving the service life of the switch.

[0022] The control method and control device according to the embodiments of the present disclosure can operate the wind turbine at a constant speed near the grid-connected wind speed.

[0023] The control method and control device according to the embodiments of the present disclosure can improve the operational safety of a wind turbine generator set. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other objects and features of the exemplary embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings which exemplarily illustrate the embodiments, in which:

[0025] Figure 1 is a block diagram showing the position of a first switch;

[0026] Figure 2 is a flowchart showing a control method according to a first embodiment of the present disclosure;

[0027] Figure 3 is a flowchart showing a control method according to a second embodiment of the present disclosure;

[0028] Figure 4 is a flowchart showing a control method according to a third embodiment of the present disclosure;

[0029] Figure 5 is a flowchart showing a control method according to a fourth embodiment of the present disclosure;

[0030] Figure 6 is a block diagram illustrating a control device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0031] The following detailed description is provided to help gain a comprehensive understanding of the methods, devices and / or systems described herein. However, the order of operations described herein is only an example and is not limited to those orders set forth herein, but may be equivalently replaced or changed except for operations that must occur or be performed in a specific order. In addition, for greater clarity and simplicity, the description of content known in the art will be omitted or simplified.

[0032] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by a person of ordinary skill in the art to which the present disclosure belongs after understanding the present disclosure. Unless explicitly defined as such herein, terms (such as those defined in a general dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the present disclosure, and should not be interpreted in an idealized or overly formal manner.

[0033] Unless otherwise specified, the same reference numerals generally refer to the same elements (e.g., components, steps, and methods). Reference numerals described in the previous embodiments may be omitted if they appear again in the subsequent embodiments. In addition, the technical features described in different or the same embodiments may be combined in any manner, as long as the combined embodiments or technical solutions are complete and can solve the technical problems of the present application or achieve the technical effects described or not described in the present application but can be determined based on the above complete technical solutions.

[0034] Figure 1 is a structural block diagram showing the position of the first switch.

[0035] Reference Figure 1According to an embodiment of the present disclosure, a wind turbine generator set may include a blade 1, a gearbox 50, a generator 30, a converter 40 and a first switch 10. The rotating shaft of the blade 1 may be connected to the main shaft of the gearbox 2. The gearbox 2 may be connected to the generator 30 and drive the generator 30 to rotate. The generator 30 may be connected to the power grid through the converter 40. For example, the converter 40 may be connected to the power grid via a transformer 20.

[0036] When the wind turbine generates electricity, the blades 1 rotate with the wind, thereby driving the gearbox 50 to rotate. After the gearbox 50 changes speed, it drives the rotor of the generator 30 to rotate, thereby obtaining an alternating magnetic field from the rotor, and the stator winding generates an alternating current with varying amplitude and frequency. The alternating current is converted into alternating current that meets the grid connection requirements via the converter 40 and is fed into the grid.

[0037] Figure 1 The structure of the wind turbine generator set shown is only an example, and the wind turbine generator set to which the control method of the present disclosure is applicable is not limited thereto. As an example, the control method of the present disclosure may be applicable to a doubly-fed wind turbine generator set.

[0038] The first switch 10 according to the embodiment of the present disclosure may be a stator circuit switch device connected to the generator of the wind turbine generator set. Figure 1 The first switch 10 is connected between the stator circuit of the wind turbine generator set and the power grid. As an example, the first switch 10 can be directly connected to the stator of the generator 30 of the wind turbine generator set. The first switch 10 can be a contactor or a circuit breaker.

[0039] As described above, when the machine needs to be shut down, the controller needs to be used to control the first switch 10 to be disconnected, and when the machine needs to be started, the controller needs to be used to control the first switch 10 to be closed.

[0040] Generally speaking, near the grid-connected wind speed (cut-in wind speed), as the wind speed fluctuates, it is necessary to frequently control the first switch 10 to be closed and disconnected, especially for a doubly-fed wind generator set, which is subject to the influence of slip voltage. When the speed of the wind generator set is lower than a certain speed, the lower the speed, the higher the slip voltage borne by the converter on the machine side. In order to avoid the converter from bearing too high a slip voltage, it is necessary to disconnect the first switch 10 when the speed of the wind generator set is lower than a certain value. In other words, since the actual wind speed changes all the time, when the wind speed is near the grid-connected wind speed, it is inevitable that the wind turbine is frequently in operation and shutdown, causing the first switch to operate frequently, resulting in a reduction in the life of the first switch. In addition, it will also affect the operating safety of the wind generator set and will also affect the power generation of the wind generator set to a certain extent.

[0041] According to the control method of the embodiment of the present disclosure, the wind turbine can maintain continuous operation at a certain speed when the wind turbine is near the grid-connected wind speed, so that the wind turbine can continue to maintain the state of the first switch (for example, the energized state) when the wind turbine is near the grid-connected wind speed, thereby minimizing the number of operations of the first switch and increasing the life of the first switch. For newly developed models, the selection difficulty of the first switch can be reduced, thereby reducing the design cost.

[0042] The control method according to the embodiment of the present disclosure adopts a hysteresis control strategy, and can control the on and off of the first switch by changing the wind speed at two moments before and after. Figure 2 This is described in detail.

[0043] Figure 2 is a flowchart illustrating a control method according to the first embodiment of the present disclosure.

[0044] Reference Figure 2 According to the first embodiment of the present disclosure, the control method may include step S110, step S120, and step S130.

[0045] In step S110, the cut-in wind speed V of the wind turbine generator set is obtained. 0 .

[0046] The cut-in wind speed here refers to the initial minimum grid-connected wind speed determined based on the airfoil and tip speed ratio of the wind turbine blades. In other words, the cut-in wind speed is the wind speed that meets the grid-connected conditions (i.e., the minimum wind speed for power generation). When the wind speed is lower than this wind speed, the wind turbine needs to be shut down. When the airfoil and tip speed ratio of the wind turbine are determined, the cut-in wind speed of the wind turbine is determined accordingly. Different models may have different cut-in wind speeds.

[0047] In step S120, the current wind speed and the previous wind speed at the location of the wind turbine generator set are obtained.

[0048] For example, the wind speed V at the location of the wind turbine can be measured by an anemometer. 1 and the wind speed V at the previous moment 2 The time interval between two adjacent moments can be determined as needed.

[0049] In step S130, in response to the current wind speed, the previous wind speed and the cut-in wind speed satisfying the first condition or satisfying the second condition, the on-off state of the first switch is kept unchanged within a preset time period.

[0050] The first condition here means: the wind speed V at the previous moment 2 Greater than the cut-in wind speed V 0 , and the current wind speed V 1 Not less than the cut-in wind speed V 0The difference between the first hysteresis control value δ and the predetermined value is not greater than the cut-in wind speed V 0 , that is, the first condition is: V 2 >V 0 、V 0 -δ≤V 1 ≤V 0 ). The second condition here refers to: the wind speed V at the previous moment 2 Less than the cut-in wind speed V 1 , and the current wind speed V 1 Not less than the cut-in wind speed V 0 And not greater than the cut-in wind speed V 0 and the sum of the first hysteresis control value δ, that is, the second condition is: V 2 <V 0 、V 0 ≤V 1 ≤V 0 +δ).

[0051] In the prior control method, when the wind speed changes from higher than or equal to the cut-in wind speed to lower than the cut-in wind speed, the first switch is controlled to be opened from the closed state. However, in the present disclosure, the first switch is controlled to remain in the closed state (at least the closed state remains unchanged during this control cycle) within a certain wind speed segment from higher than or equal to the cut-in wind speed to lower than the cut-in wind speed. Similarly, in the prior control method, when the wind speed changes from lower than the cut-in wind speed to higher than or equal to the cut-in wind speed, the first switch is controlled to change from open to closed. However, in the present disclosure, the first switch is controlled to remain in the open state (at least the open state remains unchanged during this control cycle) within a certain wind speed segment from lower than the cut-in wind speed to higher than or equal to the cut-in wind speed, thereby avoiding frequent operation of the first switch near the cut-in wind speed.

[0052] The first hysteresis control value δ may be determined differently according to the model of the wind turbine generator set, and the specific size of the first hysteresis control value δ may be determined by simulation. For non-new models, the first hysteresis control value δ may be an empirical value.

[0053] In addition, the larger the first hysteresis control value, the wider the bandwidth, and the higher the reliability of state switching, but the response and control hysteresis increase, which will cause losses such as power generation. The smaller the first hysteresis control value, the narrower the bandwidth, the faster the response speed, and the larger the power generation, but it will lead to reduced reliability and increased failure rate.

[0054] Under the premise of ensuring safety and reliability, the bandwidth can be reduced as much as possible (reducing the first hysteresis control value) to achieve a balance between reliability and control performance. As an example, the first hysteresis control value δ can be obtained through simulation and actual measurement.

[0055] As an example, when the wind speed V continues to maintain [V 0 -δ,V0 +δ], the first switch can be kept in the on state.

[0056] As an example, when the wind speed at the two moments before and after the measurement meets: V 0 -δ>V 1 And V 2 >V 0 +δ, the on-off state of the first switch can be changed, that is, the first switch is changed from an open state to a closed state.

[0057] As an example, when the wind speed at the two moments before and after the measurement meets: V 1 >V 0 +δ and V 0 -δ>V 2 When the on-off state of the first switch can be changed, that is, the first switch can be changed from a closed state to an open state.

[0058] As an example, when the wind speed at the two moments before and after the measurement meets: V 0 -δ≤V 1 ≤V 0 +δ and V 0 -δ≤V 2 ≤V 0 +δ, the on-off state of the first switch can be kept unchanged within a preset time period.

[0059] The above control method is only an example of a control method that does not meet the first condition and the second condition, and other control methods may also be used.

[0060] As an example, the control method according to an embodiment of the present disclosure may further include: in response to the wind speed at the previous moment and the wind speed at the current moment being greater than the sum of the cut-in wind speed and the first hysteresis control value, controlling the first switch to close and controlling the wind turbine generator set to operate in a preset power generation mode, where the control refers to the control method at the current moment or the current control cycle, and the control method at the previous moment or the previous control cycle may be the same as the control method at the current moment or the current control cycle; in response to the wind speed at the previous moment and the wind speed at the current moment being less than the difference between the cut-in wind speed and the first hysteresis control value, controlling the wind turbine generator set to shut down and controlling the first switch to disconnect, and similarly, the control here also refers to the control method at the current moment or the current control cycle, and the control method at the previous moment or the previous control cycle may be the same as the control method at the current moment or the current control cycle.

[0061] The control method according to the embodiment of the present disclosure may further include: in response to the wind speed V at the previous moment 2 and the current wind speed V 1 The first condition is met, or the wind speed V at the previous moment 2 and the current wind speed V1 If the second condition is met, it is determined whether the rotation speed of the wind generator set is less than a preset rotation speed; in response to the rotation speed of the wind generator set being less than the preset rotation speed, the wind generator set is controlled to operate at the preset rotation speed and the first switch is controlled to be closed.

[0062] That is to say, the wind speed V at the current moment 2 and the current wind speed V 1 The first condition or the second condition is met, and the speed of the wind turbine generator set is less than the preset speed n 0 When the wind turbine generator set is controlled to rotate at a preset speed n 0 Constant speed operation.

[0063] As an example, in response to the wind speed at the previous moment and the wind speed at the current moment both satisfying the first condition or the second condition, and the speed of the wind turbine generator set is greater than or equal to the preset speed n 0 , control the first switch to close and control the wind turbine generator set to operate according to a preset power generation mode.

[0064] The difference between the generator speed and the synchronous speed is divided by the rated speed to get the slip, and the slip is multiplied by the open circuit voltage to get the voltage value, which is required to be no greater than the upper limit of the generator side voltage. When reverse calculation, the voltage value is set to the upper limit of the generator side voltage to get the preset speed n. 0 That is to say, the preset speed n 0 It can be determined based on the limit value of the machine-side voltage of the wind turbine generator set and the open-circuit voltage of the generator of the wind turbine generator set. The limit value of the machine-side voltage and the open-circuit voltage of the generator are both known parameter values. It can be judged and controlled based on the wind speed at the current moment. When the wind speed at the current moment is [V 0 -δ,V 0 +δ], the first switch can be controlled to close, and the wind turbine generator set can be controlled to generate electricity according to the preset power generation mode to increase the power generation of the wind turbine generator set.

[0065] Figure 3 is a flowchart illustrating a control method according to a second embodiment of the present disclosure.

[0066] The control method according to the second embodiment of the present disclosure may include step S310 , step S320 , step S330 , step S340 , step S350 , step S360 , and step S370 .

[0067] In step S310, it is determined whether the current wind speed is within [V 0 -δ,V 0 +δ] range.

[0068] In step S320, in response to the current wind speed not being within [V 0 -δ,V0 +δ], and further judge whether the current wind speed is less than V 0 -δ.

[0069] In step S330, in response to the current wind speed being not less than V 0 -δ, the wind turbine generator set is controlled to generate electricity normally, that is, the wind turbine generator set can be controlled to generate electricity according to the preset power generation mode and the first switch is controlled to be closed.

[0070] In step S350, in response to the current wind speed being less than V 0 -δ, the wind turbine generator set is controlled to shut down, that is, the first switch of the wind turbine generator set can be controlled to be disconnected.

[0071] In step S340, in response to the current wind speed being [V 0 -δ,V 0 +δ], it is further determined whether the fan speed is lower than the preset speed n 0 .

[0072] In step S360, in response to the fan speed not being lower than the preset speed n 0 , the wind turbine generator set is controlled to generate electricity normally, that is, to generate electricity according to the preset power generation mode.

[0073] In step S370, in response to the fan speed being lower than the preset speed n 0 , then the wind turbine generator set is controlled to run at a steady speed n 0 mode, that is, controlling the wind turbine to rotate at a preset speed n 0 run.

[0074] The step of controlling the wind turbine to run at a preset speed may include: controlling the torque and / or pitch angle of the wind turbine to enable the wind turbine to run at the preset speed. That is, the wind turbine can achieve stable control of the wind turbine speed by coordinated pitch control and torque control. Figure 4 This is described in detail.

[0075] Figure 4 is a flowchart illustrating a control method according to a third embodiment of the present disclosure.

[0076] The control method according to the third embodiment of the present disclosure may include step S410 , step S420 , step S430 , step S440 , step S450 , and step S460 .

[0077] In step S410, it is determined whether the fan speed is stable at a preset speed n. 0 The stability here is at the preset speed n 0 Covers around the preset speed n 0Fluctuations within a certain range.

[0078] In step S420, in response to the fan speed not being stable at the preset speed n 0 , it is further determined whether the pitch angle needs to be adjusted. As an example, when the absolute value of the difference between the preset speed and the fan speed is greater than a preset threshold, it can be determined that the pitch angle needs to be adjusted. If the absolute value of the difference between the preset speed and the fan speed is less than or equal to the preset threshold, it can be determined that the pitch angle does not need to be adjusted. The preset thresholds and the like involved in the present disclosure can all be empirical values.

[0079] In step S430, in response to determining that the pitch angle needs to be adjusted, the pitch angle control function is turned on.

[0080] In step S440, in response to the fan speed not being stable at the preset speed n 0 , it is further determined whether the torque needs to be adjusted. As an example, when the absolute value of the difference between the preset speed and the fan speed is greater than a preset threshold, it can be determined that the torque needs to be adjusted; if the absolute value of the difference between the preset speed and the fan speed is less than or equal to the preset threshold, it can be determined that the torque does not need to be adjusted.

[0081] In step S450 , in response to determining that the torque needs to be adjusted, the torque control function is turned on.

[0082] In step S460, in response to the need to adjust the pitch angle or the need to adjust the torque, the current pitch angle setting and / or the current torque setting are maintained. Here, maintaining the current pitch angle setting means maintaining the reference value of the closed-loop control based on the pitch angle unchanged, and maintaining the current torque setting means maintaining the torque reference value of the closed-loop control based on the torque of the converter controller unchanged.

[0083] By sampling the above control method, the converter controller can maintain the same control topology as the power generation mode, thereby minimizing the changes to the converter controller.

[0084] As an example, the specific steps of starting the torque control function may include: when the fan speed is less than the preset speed n 0 When the absolute value of the difference between the two is greater than the preset threshold, the torque reference of the torque-based closed-loop control of the converter controller can be set to a positive reference; when the fan speed is greater than the preset speed n 0 When the absolute value of the difference between the two is greater than a preset threshold, the torque reference of the torque-based closed-loop control of the converter controller can be set to a negative reference and the torque reference value can be reduced.

[0085] As an example, the specific steps of starting the pitch angle control function may include: when the wind turbine speed is less than the preset speed n 0When the absolute value of the difference between the two is greater than the preset threshold, the pitch angle setting of the closed-loop control based on the pitch angle of the variable pitch system can be reduced; when the wind turbine speed is greater than the preset speed n 0 When the absolute value of the difference between the two is greater than a preset threshold, the pitch angle setting of the pitch angle-based closed-loop control of the variable pitch system can be increased.

[0086] In order to reduce the operating frequency of the first switch, a similar control method can also be used near the cut-out wind speed. The cut-out wind speed refers to the maximum wind speed of the wind turbine generator set connected to the grid for power generation. If the wind turbine exceeds the cut-out wind speed, the wind turbine will be cut out of the grid, the wind turbine will shut down, and stop generating electricity. The cut-out wind speed of the wind turbine is related to the blades of the wind turbine and the load of the unit, and the cut-out wind speed can also be predetermined.

[0087] Figure 5 is a flowchart illustrating a control method according to a fourth embodiment of the present disclosure.

[0088] Reference Figure 5 , the control method according to the fourth embodiment of the present disclosure may include step S510, step S520, and step S530.

[0089] In step S510, the cut-out wind speed V of the wind turbine generator set is obtained. 3 .

[0090] In step S520, the current wind speed and the previous wind speed at the location of the wind turbine generator set are obtained. For example, the current wind speed V at the location of the wind turbine generator set can be measured by an anemometer. 4 and the wind speed V at the previous moment 5 The time interval between two adjacent moments can be determined as needed. The wind speed here can refer to the average wind speed within a certain period of time.

[0091] In step S530, in response to the current wind speed V 4 , wind speed V at the previous moment 5 When the cut-out wind speed satisfies the third condition or the fourth condition, the on-off state of the first switch is kept unchanged within a preset time period.

[0092] The third condition here includes: the wind speed V at the previous moment 5 Greater than cut-out wind speed V 3 , and the current wind speed V 4 Not less than cut-out wind speed V 3 The difference between the predetermined second hysteresis control value Δ and the cut-out wind speed V 3 , that is, the third condition means: V 5 >V 3 、V 3 -Δ≤V 4 ≤V3 The fourth condition here includes: the wind speed V at the previous moment 5 Less than cut-out wind speed V 4 , and the current wind speed V 4 Not less than cut-out wind speed V 3 And not greater than the cut-out wind speed V 0 and the second hysteresis control value Δ, that is, the third condition means: V 5 <V 3 、V 3 ≤V 4 ≤V 3 +Δ.

[0093] In the prior control method, when the wind speed changes from higher than or equal to the cut-out wind speed to lower than the cut-out wind speed, the first switch is controlled to change from open to closed. However, in the present disclosure, the first switch is controlled to remain open (at least remain open during this control cycle) within a certain wind speed section where the wind speed changes from higher than or equal to the cut-out wind speed to lower than the cut-out wind speed. Similarly, in the prior control method, when the wind speed changes from lower than the cut-out wind speed to higher than or equal to the cut-out wind speed, the first switch is controlled to change from closed to open. However, in the present disclosure, the first switch is controlled to remain closed (at least remain closed during this control cycle) within a certain wind speed section where the wind speed changes from lower than the cut-out wind speed to higher than or equal to the cut-out wind speed, thereby avoiding frequent operation of the first switch near the cut-out wind speed.

[0094] The second hysteresis control value Δ can be determined differently according to the model of the wind turbine generator set, and the specific size of the second hysteresis control value Δ can be determined by simulation. For non-new models, the second hysteresis control value Δ can be an empirical value. As mentioned above, the larger the second hysteresis control value Δ is, the wider the bandwidth is, and the higher the reliability of state switching is, but the response and control hysteresis increase, which will cause losses such as power generation. The smaller the second hysteresis control value Δ is, the narrower the bandwidth is, the faster the response speed is, and the power generation is increased, but it will lead to a decrease in reliability and an increase in failure rate.

[0095] Under the premise of ensuring safety and reliability, the bandwidth is reduced as much as possible. As an example, the second hysteresis control value Δ can usually be obtained through simulation and actual measurement.

[0096] As an example, when the wind speed V continues to maintain [V 3 -Δ,V 3 +Δ], the first switch can be kept in the on state.

[0097] As an example, when the wind speed at the two moments before and after the measurement meets V 4 <V 3 -Δ and V 5 >V 3+Δ, the on-off state of the first switch can be changed, that is, the first switch is changed from the off state to the off state.

[0098] As an example, when the wind speed at the two moments before and after the measurement meets V 4 >V 3 +Δ and V 5 <V 3 -Δ, the on-off state of the first switch can be changed, that is, the first switch is changed from a closed state to an open state.

[0099] As an example, when the wind speed at the two moments before and after the measurement meets V 3 -Δ≤V 4 ≤V 3 +Δ and V 3 -Δ≤V 5 ≤V 3 +Δ, the on-off state of the first switch can be kept unchanged within a preset time period.

[0100] Figure 6 is a block diagram illustrating a control device according to an embodiment of the present disclosure.

[0101] The control device 600 according to an embodiment of the present disclosure may include a cut-in wind speed acquisition unit 610 , a wind speed acquisition unit 620 , and a control unit 630 .

[0102] The cut-in wind speed acquisition unit 610 may acquire the cut-in wind speed of the wind turbine generator set. The cut-in wind speed acquisition unit 610 may determine the cut-in wind speed of the wind turbine generator set by calculation or simulation.

[0103] The wind speed acquisition unit 620 can acquire the current wind speed and the previous wind speed at the location of the wind turbine generator set. The wind speed acquisition unit 620 can be an anemometer or a software module that obtains output data of the anemometer.

[0104] The control unit 630 may maintain the on / off state of the first switch unchanged within a preset time period in response to the current wind speed, the previous wind speed, and the cut-in wind speed satisfying the first condition or satisfying the second condition.

[0105] Although not shown, the control device 600 according to the embodiment of the present disclosure may further include a cut-out wind speed acquisition unit. The control unit 630 may keep the on / off state of the first switch unchanged within a preset time period in response to the current wind speed, the previous wind speed, and the cut-out wind speed satisfying the third condition or satisfying the fourth condition. The control unit 630 may execute Figures 2 to 5 The control steps shown in .

[0106] The first condition, the second condition, the third condition and the fourth condition can all be as described above and will not be repeated here.

[0107] The control method according to the embodiment of the present disclosure can be executed by a processor and can be written as a corresponding computer program or code. The control method, device, etc. according to the embodiment of the present disclosure have been described above with reference to the accompanying drawings. However, it should be understood that the units, devices, and modules shown in the accompanying drawings can be configured as software, hardware, firmware, or any combination of the above items to perform specific functions. For example, these systems and modules may correspond to dedicated integrated circuits, pure software codes, or modules that combine software and hardware. In addition, one or more functions implemented by these devices and modules may also be uniformly executed by components in physical entity devices (e.g., processors, clients, or servers, etc.).

[0108] The instructions stored in the above-mentioned computer-readable storage medium can be executed in an environment deployed in computer devices such as a client, a host, a proxy device, a server, etc. It should be noted that the instructions can also be used to execute additional steps in addition to the above-mentioned steps or to perform more specific processing when executing the above-mentioned steps. The contents of these additional steps and further processing have been mentioned in the description of relevant modules, methods and devices with reference to the accompanying drawings, so they will not be repeated here to avoid repetition.

[0109] It should be noted that the control method and control device according to the embodiments of the present disclosure can completely rely on the operation of computer programs or instructions to realize the corresponding functions, that is, each device corresponds to each step in the functional architecture of the computer program, so that the entire system is called through a special software package (for example, lib library) to realize the corresponding function.

[0110] On the other hand, when the device or system is implemented in software, firmware, middleware or microcode, the program code or code segment for performing the corresponding operation can be stored in a computer-readable medium such as a storage medium, so that at least one processor or at least one computing device can perform the corresponding operation by reading and running the corresponding program code or code segment. In addition, the computer-readable medium or storage medium can cause the processor to execute the above-mentioned control method when the computer program is executed by the processor.

[0111] For example, according to an exemplary embodiment of the present disclosure, a computer device including a readable medium storing computer program instructions may be provided, wherein when the instructions are executed by at least one computing device, the at least one computing device is prompted to perform at least one of the above steps.

[0112] According to an embodiment of the present disclosure, a computer-readable storage medium is provided, which stores instructions or programs. When the instructions or programs are executed by a processor, the processor is prompted to execute the above control method.

[0113] Computer-readable storage media include non-transitory computer-readable storage media, for example, magnetic media such as floppy disks and tapes, optical media (including compact disks (CD) ROMs and DVD ROMs), magneto-optical media such as floppy disks, hardware devices such as ROMs, RAMs, and flash memories designed to store and execute program commands. The program commands include language codes executable by a computer using an interpreter and machine language codes generated by a compiler. The above-mentioned hardware devices can be implemented by one or more software modules for performing the operations of the various embodiments of the present disclosure.

[0114] According to an embodiment of the present disclosure, a controller of a wind turbine generator set is provided, the controller comprising a memory and a processor, the memory storing a program or code, and when the program or code is executed by the processor, the processor is prompted to execute the above control method of the wind turbine generator set.

[0115] According to an embodiment of the present disclosure, a wind turbine generator set is provided, which includes a first switch connected between a stator circuit of the wind turbine generator set and a power grid, and the above-mentioned control device or the above-mentioned controller.

[0116] The control method and control device according to the embodiments of the present disclosure can avoid frequent operation of the first switch, reduce the number of operations of the first switch when the wind turbine runs near the grid-connected speed, increase the service life of the first switch, and improve the reliability of the wind turbine throughout its life cycle.

[0117] The control method and control device according to the embodiments of the present disclosure can reduce the difficulty of selecting the first switch. By reducing the number of actions of the first switch, the selection requirements for the first switch can be significantly reduced, providing support for cost-reduction development of wind turbines.

[0118] The control method and control device according to the embodiments of the present disclosure can improve the operational safety of the wind turbine generator set and increase the power generation of the wind turbine generator set.

[0119] Although some exemplary embodiments of the present disclosure have been shown and described, it will be understood by those skilled in the art that modifications may be made to these embodiments without departing from the principles and spirit of the present disclosure, the scope of which is defined by the claims and their equivalents; for example, the technical features of different embodiments may be combined.

Claims

1. A control method for a wind turbine generator set, It is characterized in that The wind turbine generator set comprises a first switch connected between a stator circuit of the wind turbine generator set and a power grid, and the control method comprises: Obtain the cut-in wind speed of the wind turbine generator set; Obtaining the current wind speed and the previous wind speed at the location of the wind turbine generator set; In response to the wind speed at the current moment, the wind speed at the previous moment, and the cut-in wind speed satisfying a first condition or satisfying a second condition, maintaining the on-off state of the first switch unchanged within a preset time period; The first condition refers to: the wind speed at the previous moment is greater than the cut-in wind speed, and the wind speed at the current moment is not less than the difference between the cut-in wind speed and a predetermined first hysteresis control value and not greater than the cut-in wind speed; The second condition is that the wind speed at the previous moment is less than the cut-in wind speed, and the wind speed at the current moment is not less than the cut-in wind speed and not greater than the sum of the cut-in wind speed and the first hysteresis control value.

2. The control method of the wind turbine generator set according to claim 1, It is characterized in that The control method further comprises: In response to the wind speed at a previous moment and the wind speed at the current moment both satisfying the first condition, or the wind speed at a previous moment and the wind speed at the current moment both satisfying the second condition, determining whether the rotation speed of the wind turbine generator set is less than a preset rotation speed; In response to the rotation speed of the wind turbine generator set being less than the preset rotation speed, the wind turbine generator set is controlled to operate at the preset rotation speed and the first switch is controlled to be closed.

3. The control method of the wind turbine generator set according to claim 2, It is characterized in that The preset rotation speed is determined based on a limit value of a machine-side voltage of the wind turbine generator set and an open-circuit voltage of a generator of the wind turbine generator set.

4. The control method of the wind turbine generator set according to claim 2, It is characterized in that The step of controlling the wind turbine generator set to operate at the preset rotational speed includes: controlling the torque and / or pitch angle of the wind turbine generator set to enable the wind turbine generator set to operate at the preset rotational speed.

5. The control method of the wind turbine generator set according to claim 2, It is characterized in that In response to the wind speed at the previous moment and the wind speed at the current moment both satisfying the first condition or the second condition, and the rotation speed of the wind turbine generator set is greater than or equal to the preset rotation speed, the first switch is controlled to close and the wind turbine generator set is controlled to operate according to a preset power generation mode.

6. The control method of a wind turbine generator set according to any one of claims 1 to 5, It is characterized in that The control method further comprises: In response to the wind speed at the previous moment and the wind speed at the current moment being greater than the sum of the cut-in wind speed and the first hysteresis control value, the first switch is controlled to close and the wind turbine generator set is controlled to operate according to a preset power generation mode.

7. The control method of the wind turbine generator set according to claim 6, It is characterized in that The control method further includes: in response to the wind speed at the previous moment and the wind speed at the current moment being less than the difference between the cut-in wind speed and the first hysteresis control value, controlling the wind turbine generator set to shut down and controlling the first switch to open.

8. The control method of a wind turbine generator set according to claim 1, It is characterized in that The control method further comprises: Obtain the cut-out wind speed of the wind turbine generator set; In response to the wind speed at the previous moment, the wind speed at the current moment, and the cut-out wind speed satisfying a third condition or satisfying a fourth condition, maintaining the on-off state of the first switch unchanged within a preset time period; The third condition includes: the wind speed at the previous moment is greater than the cut-out wind speed, and the wind speed at the current moment is not less than the difference between the cut-out wind speed and a predetermined second hysteresis control value and not greater than the cut-out wind speed; The fourth condition includes: the wind speed at the previous moment is less than the cut-out wind speed, and the wind speed at the current moment is not less than the cut-out wind speed and not greater than the sum of the cut-out wind speed and the second hysteresis control value.

9. The control method of a wind turbine generator set according to claim 1, It is characterized in that The cut-in wind speed is an initial minimum grid-connected wind speed determined according to the airfoil and tip speed ratio of the blades of the wind turbine generator set.

10. A computer-readable storage medium, It is characterized in that The computer-readable storage medium stores a program or code, which, when executed by a processor, causes the processor to execute the control method for a wind turbine generator set according to any one of claims 1 to 9.

11. A control device for a wind turbine generator set, It is characterized in that The wind turbine generator set comprises a first switch connected between a stator circuit of the wind turbine generator set and a power grid, and the control device comprises: A cut-in wind speed acquisition unit is used to acquire the cut-in wind speed of the wind turbine generator set; A wind speed acquisition unit, for acquiring the current wind speed and the previous wind speed at the location of the wind turbine generator set; A control unit, in response to the wind speed at the current moment, the wind speed at the previous moment, and the cut-in wind speed satisfying a first condition or satisfying a second condition, maintaining the on-off state of the first switch unchanged within a preset time period; The first condition refers to: the wind speed at the previous moment is greater than the cut-in wind speed, and the wind speed at the current moment is not less than the difference between the cut-in wind speed and a predetermined first hysteresis control value and not greater than the cut-in wind speed; The second condition is that the wind speed at the previous moment is less than the cut-in wind speed, and the wind speed at the current moment is not less than the cut-in wind speed and not greater than the sum of the cut-in wind speed and the first hysteresis control value.

12. A controller for a wind turbine generator set, It is characterized in that The invention comprises a memory and a processor, wherein the memory stores a program or code, and when the program or code is executed by the processor, the processor is prompted to execute the control method of the wind turbine generator set according to any one of claims 1 to 9.

13. A wind turbine generator set, It is characterized in that The wind turbine generator set comprises a first switch connected between a stator circuit of the wind turbine generator set and a power grid, and a control device according to claim 11 or a controller according to claim 12.

Images