Wind turbine generator and variable pitch system backup power supply energy demand calculation method and system thereof

Abstract

The invention discloses a wind turbine generator and a variable pitch system backup power supply energy demand calculation method and system, and the method comprises the steps: dividing a power grid power-down blade emergency feathering angle range of a wind turbine generator into a plurality of segments, enabling each segment to correspond to a variable pitch angle interval, and collecting the variable pitch speed in each segment; the variable-pitch motor torque and the variable-pitch motor rotating speed in each section are calculated; according to the variable-pitch motor torque value and the variable-pitch motor rotating speed of each section, back-up power source energy in each section is obtained through calculation; calculating energy consumed by low voltage ride through during emergency feathering of blades during power failure of a power grid of the wind turbine generator; summing the obtained energy of the back-up power supply of each segment and the calculated energy consumed by low voltage ride through during emergency feathering of the blades during power failure of the power grid of the wind generating set to obtain the total energy of the back-up power supply required by emergency feathering under the power failure condition of the power grid of the wind generating set. The system comprises each module corresponding to each step of the method.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine generator sets, and in particular to a method and system for calculating energy demand of a backup power supply of a wind turbine generator set and a pitch control system thereof. Background Art

[0002] The pitch control system is installed in the hub of the wind turbine and is one of the core components of the wind turbine. It is used to control the blade angle of the wind turbine. The pitch backup power supply is an important part of the pitch control system. It provides backup energy for the pitch control system to drive the blades to retract when the wind turbine loses power, ensuring that the blades are aligned to a safe position to achieve the effect of wind rotor braking. If there is no pitch backup power supply or the energy of the backup power supply is insufficient, the wind turbine blades cannot be aligned, which may cause a wind turbine accident. Therefore, how to reasonably calculate the energy required for the wind turbine pitch backup power supply is crucial to the safety and cost of the wind turbine.

[0003] At present, the energy demand for the backup power supply of the variable pitch system is calculated directly using the rated torque and rated speed of the variable pitch motor. No segmented pitch is performed in the entire emergency retraction angle range. The same variable pitch motor torque and speed are used throughout the entire process. The emergency retraction condition due to power outage is not close to the grid. The torque and speed of the variable pitch motor selected in this way are greater than those of the emergency retraction condition. The calculated energy is too large, resulting in waste and increased cost, which is not economical. Summary of the invention

[0004] In order to solve some or all of the technical problems existing in the above-mentioned prior art, the present invention provides a method and system for calculating the backup power supply energy demand of a wind turbine set and its variable pitch system, which can more reasonably calculate the backup power supply energy required for safe propeller adjustment of the blades in the event of an emergency situation where the wind turbine set loses power from the power grid. This can not only ensure the safety of the wind turbine set, but also avoid wasting the backup power supply energy, thus being more economical.

[0005] The technical solution of the present invention is as follows:

[0006] In a first aspect, the present invention provides a method for calculating the energy demand of a backup power supply of a wind turbine pitch control system, comprising:

[0007] The emergency feathering angle range of the wind turbine blades during power outage is divided into several segments, so that each segment corresponds to a pitch angle interval, and the pitch speed in each segment is collected;

[0008] Calculate the pitch motor torque and pitch motor speed in each segment respectively;

[0009] The backup power supply energy in each segment is calculated based on the pitch motor torque value and pitch motor speed of each segment;

[0010] Calculate the energy consumed by low voltage ride-through when the wind turbine blades are urgently feathered when the grid loses power;

[0011] The obtained backup power supply energy of each segment and the calculated energy consumed by low voltage ride-through when the wind turbine blades are urgently feathered when the power grid is lost are summed to obtain the total backup power supply energy required for emergency feathering of the wind turbine blades when the power grid is lost.

[0012] Furthermore, in the above-mentioned method for calculating the energy demand of the backup power supply of the variable pitch system of a wind turbine, the angle range includes: 0° to 90°.

[0013] Furthermore, in the above-mentioned method for calculating the energy demand of the backup power supply of the wind turbine pitch control system, the emergency feathering angle range of the wind turbine blades when the power grid is off is divided into several sections including:

[0014] The angle range is divided according to equal angle division, special angle division or equal difference angle division or one or more angle division methods.

[0015] Furthermore, in the above-mentioned method for calculating the energy demand of the backup power supply of the variable pitch system of a wind turbine, the special angles include: 0°, 30°, 45°, 60° and 90°.

[0016] Furthermore, in the above-mentioned method for calculating the energy demand of the backup power supply of the wind turbine pitch control system, calculating the torque of the pitch control motor in each segmented pitch control angle interval includes:

[0017] According to the IEC61400-1 standard and the Germanischer Lloyd's GL wind turbine certification guide, the grid power-off working condition of the wind turbine is set, and the emergency pitch retraction simulation calculation is performed for each segmented pitch angle interval. The blade root load data timing file from the rated wind speed to the cut-out wind speed is output, and the emergency pitch retraction and pitch motor side torque root mean square value at each wind speed in each segmented pitch interval is obtained. The obtained pitch motor side torque root mean square value is averaged to obtain the emergency pitch retraction and pitch motor torque value in each segmented pitch angle interval under the grid power-off condition.

[0018] Furthermore, in the above-mentioned method for calculating the energy demand of the backup power supply of the wind turbine pitch system, the torque and speed of the pitch motor in each segment are calculated using the following formula:

[0019] N t =D t ×(60 / 360)×i;

[0020] Among them, N tIt represents the speed of the variable pitch motor in any segment of the wind turbine blade emergency feathering angle range when the power grid is off, D t It represents the pitch speed corresponding to any segment in the emergency feathering angle range of the wind turbine blades when the power grid is off, and i represents the total speed ratio of the pitch system.

[0021] Furthermore, in the above-mentioned method for calculating the backup power supply energy demand of the wind turbine pitch system, according to the pitch motor torque value and pitch motor speed of each segment, the backup power supply energy in each segment is calculated and determined by the following formula:

[0022]

[0023] Among them, B t represents any segment selected from the several segments divided into the emergency feathering angle range of the wind turbine blades when the power grid is off; B t+1 It represents the adjacent segment of any segment selected in the emergency feathering angle range of the wind turbine blades when the power grid is off, and segment B t+1 The angle value of the corresponding propeller angle interval is greater than that of segment B. t The angle value of the corresponding propeller angle range, B t+1 The maximum value of the pitch angle interval corresponding to the segment is less than or equal to 90°, B t The minimum angle value of the pitch angle interval corresponding to the segment is greater than or equal to 0°; D t It represents the pitch speed corresponding to any segment selected in the emergency pitch angle range of the wind turbine blades when the power grid is off; E t It represents the energy required for changing the pitch once within the corresponding angle range of any segment selected from the emergency feathering angle range of the wind turbine blades when the power grid is off; T t It represents the motor torque value corresponding to any segment selected in the emergency pitch angle range of the wind turbine blades when the power grid is off; η1 represents the efficiency of the wind turbine pitch reducer; η2 represents the efficiency of the wind turbine pitch motor; η3 represents the efficiency of the wind turbine pitch drive.

[0024] Furthermore, in the above-mentioned method for calculating the energy demand of the backup power supply of the wind turbine pitch control system, the energy consumed by the low voltage ride-through when the wind turbine grid loses power and the blades are urgently feathered is calculated by the following formula:

[0025]

[0026] Among them, E z It represents the energy consumed by the wind turbine when the blades are urgently feathered due to a low voltage ride-through for a duration of m. 额 Indicates the rated torque of the wind turbine pitch motor, N zIt represents the rated torque of the wind turbine pitch motor and the motor speed at normal pitch speed. m represents the pitch time of the wind turbine during low voltage ride-through.

[0027] In a second aspect, the present invention provides a system for calculating energy demand of a backup power supply of a wind turbine pitch control system, comprising:

[0028] A segmented acquisition module, which is used to divide the wind turbine blade emergency feathering angle range when the power grid is powered off into several segments, so that each segment corresponds to a pitch angle interval, and collect the pitch speed in each segment;

[0029] A torque and speed calculation module, which is used to calculate the torque and speed of the pitch motor in each segment respectively;

[0030] A segmented backup power supply energy calculation module, wherein the segmented backup power supply energy calculation module is used to calculate the backup power supply energy in each segment according to the pitch motor torque value and pitch motor speed of each segment;

[0031] A low voltage ride-through energy calculation module, which is used to calculate the energy consumed by low voltage ride-through when the wind turbine generator set loses power and its blades are urgently feathered;

[0032] A total energy calculation module is used to sum the backup power supply energy of each segment obtained and the energy consumed by the low voltage ride-through when the wind turbine blades are urgently aligned when the power grid is lost, so as to obtain the total backup power supply energy required for emergency alignment when the wind turbine blades are urgently aligned when the power grid is lost.

[0033] In a third aspect, the present invention provides a wind turbine generator set, on which is provided a wind turbine generator set pitch control system backup power supply energy demand calculation system as described above.

[0034] The main advantages of the technical solution of the present invention are as follows:

[0035] The method for calculating the energy demand of the backup power supply of the variable pitch system of the wind turbine set of the present invention can further reduce the load by adopting a segmented variable pitch method for the blade retraction of the wind turbine set under the emergency condition of power outage of the power grid, and adopting different variable pitch speeds in different segmented variable pitch angle intervals. When calculating the energy of the variable pitch backup power supply, the torque and speed of the variable pitch motor are respectively obtained in the segmented variable pitch angle interval, so as to obtain the backup power supply energy in each segmented variable pitch angle interval, which is closer to the actual emergency condition and the energy calculation is more reasonable. At the same time, combined with the variable pitch energy demand of the wind turbine set under the low voltage crossing condition, the total backup power supply energy required for emergency propeller alignment of the wind turbine set under the condition of power outage of the power grid is finally calculated, providing a design input basis for the reasonable selection of the backup power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings described herein are used to provide a further understanding of the embodiments of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0037] Figure 1 A schematic flow chart of a method for calculating energy demand of a backup power supply of a wind turbine pitch control system according to an embodiment of the present invention;

[0038] Figure 2 A schematic diagram of the structure of a system for calculating the energy demand of a backup power supply of a wind turbine pitch control system provided in one embodiment of the present invention.

[0039] Description of reference numerals:

[0040] 10. Segmented acquisition module; 20. Torque and speed calculation module; 30. Segmented backup power supply energy calculation module; 40. Low voltage ride-through energy calculation module; 50. Total energy calculation module. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0042] The following is combined with Figure 1-2 , describes in detail the technical solution provided by the embodiments of the present invention.

[0043] As attached Figure 1 As shown, an embodiment of the present invention provides a method for calculating the energy demand of a backup power supply of a wind turbine pitch control system, the method comprising steps S1 to S5:

[0044] Step S1: dividing the wind turbine blade emergency feathering angle range when the power grid is off into several segments, so that each segment corresponds to a pitch angle interval, and collecting the pitch speed in each segment;

[0045] Specifically, the above angle range includes: 0° to 90°.

[0046] In some optional implementations of this embodiment, dividing the wind turbine generator grid power failure blade emergency feathering angle range into several segments includes: dividing the angle range according to equal angles, according to special angles, or using one or more angle division methods of equal angle division. For example, the above-mentioned 0° to 90° angle range is divided according to 5°, 10°, 15°, 20° or any angle difference; for example, it is divided according to special angles such as 0°, 30°, 45°, 60° and 90°.

[0047] It should be noted that the above specific division method is determined according to the actual application, actual needs and actual situation. It is understandable that the more segments are divided, the more data collected and calculated, and the more accurate the final calculated result. However, in order to improve the calculation efficiency and ensure the accuracy of the calculation, at least five segments are divided during the calculation process, and at least not less than three segments.

[0048] Specifically, in the method for calculating the energy demand of the backup power supply of the wind turbine pitch system of the present invention, calculating the torque of the pitch motor in each segmented pitch angle interval includes:

[0049] According to the IEC61400-1 standard and the Germanischer Lloyd's GL wind turbine certification guide, the grid power-off working condition of the wind turbine is set, and the emergency pitch retraction simulation calculation is performed for each segmented pitch angle interval. The blade root load data timing file from the rated wind speed to the cut-out wind speed is output, and the emergency pitch retraction and pitch motor side torque root mean square value at each wind speed in each segmented pitch interval is obtained. The obtained pitch motor side torque root mean square value is averaged to obtain the emergency pitch retraction and pitch motor torque value in each segmented pitch angle interval under the grid power-off condition.

[0050] Step S2: Calculate the pitch motor torque and pitch motor speed in each segment respectively;

[0051] Specifically, the pitch motor torque and pitch motor speed in each segment are calculated using the following formula:

[0052] N t =D t ×(60 / 360)×i;

[0053] Among them, N t It represents the speed of the variable pitch motor in any segment of the wind turbine blade emergency feathering angle range when the power grid is off, D t It represents the pitch speed corresponding to any segment in the emergency feathering angle range of the wind turbine blades when the power grid is off, and i represents the total speed ratio of the pitch system.

[0054] Specifically, the total speed ratio i of the above-mentioned variable pitch system can be obtained by the following calculation method:

[0055] After the number of teeth on the inner gear ring of the wind turbine pitch bearing, the number of teeth on the pitch drive pinion, and the speed ratio of the pitch drive reducer are selected, the total speed ratio i of the pitch system can be calculated using the above-determined parameters.

[0056] Step S3: Calculate the backup power supply energy in each segment according to the pitch motor torque value and pitch motor speed of each segment;

[0057] Specifically, according to the pitch motor torque value and pitch motor speed of each segment, the backup power supply energy in each segment is calculated and determined by the following formula:

[0058]

[0059] Among them, B t represents any segment selected from the several segments divided into the emergency feathering angle range of the wind turbine blades when the power grid is off; B t+1 It represents the adjacent segment of any segment selected in the emergency feathering angle range of the wind turbine blades when the power grid is off, and segment B t+1 The angle value of the corresponding propeller angle interval is greater than that of segment B. t The angle value of the corresponding propeller angle range, B t+1 The maximum value of the pitch angle interval corresponding to the segment is less than or equal to 90°, B t The minimum angle value of the pitch angle interval corresponding to the segment is greater than or equal to 0°; D t It represents the pitch speed corresponding to any segment selected in the emergency pitch angle range of the wind turbine blades when the power grid is off; E t It represents the energy required for changing the pitch once within the corresponding angle range of any segment selected from the emergency feathering angle range of the wind turbine blades when the power grid is off; T t It represents the motor torque value corresponding to any segment selected in the emergency pitch angle range of the wind turbine blades when the power grid is off; η1 represents the efficiency of the wind turbine pitch reducer; η2 represents the efficiency of the wind turbine pitch motor; η3 represents the efficiency of the wind turbine pitch drive.

[0060] Step S4: calculating the energy consumed by low voltage ride-through when the wind turbine generator set loses power and its blades are urgently feathered;

[0061] Specifically, the energy consumed by low voltage ride-through when the blades of a wind turbine are urgently feathered due to power failure of the power grid is calculated by the following formula:

[0062]

[0063] Among them, E zIt represents the energy consumed by the wind turbine when the blades are urgently feathered due to a low voltage ride-through for a duration of m. 额 Indicates the rated torque of the wind turbine pitch motor, N z It represents the rated torque of the wind turbine pitch motor and the motor speed at normal pitch speed. m represents the pitch time of the wind turbine during low voltage ride-through.

[0064] Specifically, the rated torque of the wind turbine pitch motor is N z Calculated by the following formula:

[0065] N z =D z ×(60 / 360)×i;

[0066] Among them, D z Indicates the normal pitch speed of the wind turbine;

[0067] In some optional implementations of the present embodiment, the pitch change duration m of the above-mentioned wind turbine during low voltage crossing is usually taken as 3 based on prior knowledge and practical applications. Of course, it can be understood that the above-mentioned value is not fixed, nor is it the only limitation thereto. Data obtained according to actual needs and the latest application data and the latest research results can be used, and any value can be taken for calculation during the calculation process.

[0068] Step S5: summing the obtained backup power supply energy of each segment and the calculated energy consumed by low voltage ride-through when the wind turbine blades are urgently feathered when the power grid is lost, to obtain the total backup power supply energy required for emergency feathering when the wind turbine blades are urgently feathered when the power grid is lost.

[0069] Therefore, the method for calculating the energy demand of the backup power supply of the wind turbine pitch system of the present invention can further reduce the load by adopting a segmented pitching method to retract the blades of the wind turbine under the emergency condition of power outage of the power grid, and adopting different pitching speeds in different segmented pitching angle intervals. When calculating the energy of the backup power supply of the pitching, the torque and speed of the pitching motor are respectively obtained in the segmented pitching angle interval, so as to obtain the backup power supply energy in each segmented pitching angle interval. This energy is closer to the actual emergency condition, and the energy calculation is more reasonable. At the same time, combined with the energy demand of the wind turbine under the low voltage crossing condition, the total energy of the backup power supply required for emergency propeller alignment of the wind turbine under the condition of power outage of the power grid is finally calculated, providing a design input basis for the reasonable selection of the backup power supply.

[0070] The following is a specific description of how the present invention calculates the energy demand of the backup power supply of the wind turbine pitch control system in combination with practical applications:

[0071] The emergency feathering angle range of the wind turbine blades is 0° to 90°, and the wind turbine blades are retracted using segmented variable pitch speed in the event of an emergency power outage. For example, the above 0° to 90° angle range is divided into segments as shown in Table 1 below.

[0072] Table 1: The range of emergency feathering angles of wind turbine blades during power outage is divided into several sections

[0073] Pitch angle range (°) Pitch speed (° / s) 0°～B0 D0 B0~B1 D1 B1~B2 D2 … … Bt~90°(Bt<90°) Dt

[0074] Calculate the pitch motor side torque

[0075] In the present invention, according to the parameters of the wind turbine components, a simulation model of the wind turbine is established on the simulation platform, and the power-off condition of the wind turbine is set according to the IEC61400-1 standard and the Germanischer Lloyd's GL wind turbine certification guide. Emergency retraction simulation calculation is performed for each segmented pitch angle interval, and the blade root load data timing file from the rated wind speed to the cut-out wind speed (every 0.5m / s) is output, from which the emergency retraction pitch motor side torque root mean square value at each wind speed in each segmented pitch interval is obtained, and then the torque root mean square value of the pitch motor side is averaged, so that the emergency retraction pitch motor torque value in each segmented pitch angle interval under the power-off condition of the grid can be obtained. For example, for the segments divided in Table 1 above:

[0076] The torque value of the emergency retracting pitch motor in the pitch angle range of 0° to B0 is T0, and the unit of the pitch motor torque value is Nm;

[0077] The torque value of the emergency retracting pitch motor in the pitch angle range B0 to B1 is T1, and the unit of the pitch motor torque value is Nm;

[0078] The torque value of the emergency retracting pitch motor in the pitch angle interval B1 to B2 is T2, and the unit of the pitch motor torque value is Nm;

[0079] By analogy, in the pitch angle range B t The torque value of the emergency retracting and pitch changing motor within 90° is T t , the pitch motor torque value is in Nm.

[0080] Calculate the pitch motor speed

[0081] After the number of teeth on the inner gear ring of the wind turbine pitch bearing, the number of teeth on the pitch drive pinion, and the speed ratio of the pitch drive reducer are determined, the total speed ratio i of the pitch system can be calculated.

[0082] For the pitch angle range of 0° to B0, the pitch speed is D0, and the corresponding pitch motor speed can be calculated: N0 = D0 × (60 / 360) × i, where the unit of pitch motor speed is rpm;

[0083] For the pitch angle range B0~B1, the pitch speed is D1, and the corresponding pitch motor speed can be calculated:

[0084] N1=D1×(60 / 360)×i, the unit of pitch motor speed is rpm;

[0085] For the pitch angle range B1 to B2, the pitch speed is D2, and the corresponding pitch motor speed can be calculated:

[0086] N2=D2×(60 / 360)×i, the unit of the pitch motor speed is rpm;

[0087] By analogy, for the pitch angle range B t ~90°, its pitch speed is D t , the corresponding variable pitch motor speed N can be calculated t =D t ×(60 / 360)×i, the unit of pitch motor speed is rpm.

[0088] Calculate the energy required for the pitch backup power supply

[0089] For the pitch angle range of 0° to B0 and the pitch speed D0, the energy E0 (in kJ) required for one pitch change within this angle range can be calculated:

[0090] Among them, η1 is the efficiency of the variable pitch reducer, η2 is the efficiency of the variable pitch motor, and η3 is the efficiency of the variable pitch drive;

[0091] For the pitch angle range B0~B1 and pitch speed D1, the energy E1 (in kJ) required for one pitch change within the angle range can be calculated:

[0092]

[0093] For the pitch angle range B1-B2 and pitch speed D2, the energy E2 (in kJ) required for one pitch change within the angle range can be calculated:

[0094]

[0095] By analogy, for the pitch angle range B t ~90°, pitch speed D t , the energy Et (in kJ) required for pitch change within this angle range can be calculated:

[0096]

[0097] In addition, the energy calculation of the backup power supply of the wind turbine pitch system also needs to consider the energy consumed by the wind turbine when low voltage ride-through occurs. The low voltage ride-through of the wind turbine generally considers the normal pitch time to be 3 seconds and the rated torque of the pitch motor to be T 额 , the normal pitch speed is D z (unit: ° / s), from which the corresponding variable pitch motor speed can be calculated: N z =D z ×(60 / 360)×i, the unit of pitch motor speed is rpm. The following formula can be used to calculate the pitch backup power energy Ez (in kJ) required for the wind turbine to run low for 3 seconds in the event of a power outage:

[0098]

[0099] Combining the energy obtained from the above calculations, the total energy E of the backup power supply required for the wind turbine to complete a safe pitching operation normally when the wind turbine is out of power is further calculated. 总 , (unit is kJ):

[0100] E 总 =E0+E1+E2+…+Et+Ez.

[0101] In summary, the calculation method adopted by the present invention is that the wind turbine generator set adopts segmented variable pitch speed for emergency retraction under the condition of power outage in the power grid. In each segmented angle interval, the variable pitch speed suitable for the working condition is determined, and the segmented variable pitch motor speed is further obtained; the segmented variable pitch motor torque is calculated according to the time series file of the blade retraction load in each segmented angle interval, and the energy required for the segmented emergency retraction is further calculated from the torque and speed of each segmented variable pitch motor; and then combined with the energy required for the low penetration of the wind turbine, the total energy required for the backup power supply of the variable pitch system is obtained. The energy calculated in this way is closer to the actual working condition, and the calculated energy can meet the emergency retraction energy demand in the case of power outage in the power grid without being wasted, which ensures the safety of the wind turbine generator set and achieves economy. At the same time, the calculation method is convenient and fast, suitable for various segmented emergency retraction situations, and can greatly improve the calculation efficiency of the energy demand of the variable pitch backup power supply.

[0102] Second, as Figure 2 As shown, the present invention also provides a wind turbine variable pitch system backup power supply energy demand calculation system, including: a segmented acquisition module 10, a torque and speed calculation module 20, a segmented backup power supply energy calculation module 30, a low voltage ride-through energy calculation module 40 and a total energy calculation module 50, wherein:

[0103] The segmented acquisition module 10 is used to divide the emergency pitching angle range of the wind turbine blades when the power grid is cut off into several segments, so that each segment corresponds to a pitch angle interval, and collects the pitch speed in each segment; the torque and speed calculation module 20 is used to respectively calculate the torque and speed of the pitch motor in each segment; the segmented backup power supply energy calculation module 30 is used to calculate the backup power supply energy in each segment according to the torque value and speed of the pitch motor in each segment; the low voltage ride-through energy calculation module 40 is used to calculate the energy consumed by low voltage ride-through when the wind turbine blades are urgently feathered when the power grid is cut off; the total energy calculation module 50 is used to sum the backup power supply energy of each segment obtained and the calculated energy consumed by low voltage ride-through when the wind turbine blades are urgently feathered when the power grid is cut off, so as to obtain the total backup power supply energy required for emergency pitching of the wind turbine when the power grid is cut off.

[0104] Therefore, through the wind turbine variable pitch system backup power supply energy demand calculation system of the present invention, the backup power supply energy required for safe blade alignment in the event of an emergency situation where the wind turbine generator set loses power from the power grid can be calculated more reasonably, which can not only ensure the safety of the wind turbine generator set, but also avoid wasting backup power supply energy, and is more economical.

[0105] In a third aspect, the present invention provides a wind turbine generator set, on which is provided the wind turbine generator set pitch control system backup power supply energy demand calculation system as described above.

[0106] Such an arrangement enables the wind turbine to more reasonably calculate the backup power energy required for safe blade alignment in the event of an emergency power outage in the wind turbine, which can ensure the safety of the wind turbine without wasting backup power energy and is more economical.

[0107] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In addition, "front", "back", "left", "right", "upper" and "lower" in this article are all referenced to the placement state shown in the accompanying drawings.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the energy demand of a backup power supply of a wind turbine pitch control system, characterized in that: include: The emergency feathering angle range of the wind turbine blades during power outage is divided into several segments, so that each segment corresponds to a pitch angle interval, and the pitch speed in each segment is collected; Calculate the pitch motor torque and pitch motor speed in each segment respectively; The backup power supply energy in each segment is calculated based on the pitch motor torque value and pitch motor speed of each segment; Calculate the energy consumed by low voltage ride-through when the wind turbine blades are urgently feathered when the grid loses power; The obtained backup power supply energy of each segment and the calculated energy consumed by low voltage ride-through when the wind turbine blades are urgently feathered when the power grid is lost are summed to obtain the total backup power supply energy required for emergency feathering of the wind turbine blades when the power grid is lost.

2. The method for calculating the energy demand of the backup power supply of the wind turbine pitch control system according to claim 1 is characterized in that: The angle range includes: 0° to 90°.

3. The method for calculating the energy demand of the backup power supply of the wind turbine pitch control system according to claim 1 is characterized in that: The emergency feathering angle range of the wind turbine blades during power outage is divided into several sections, including: The angle range is divided according to equal angle division, special angle division or equal difference angle division or one or more angle division methods.

4. The method for calculating the energy demand of the backup power supply of the wind turbine pitch control system according to claim 3 is characterized in that: The special angles include: 0°, 30°, 45°, 60° and 90°.

5. The method for calculating the energy demand of the backup power supply of the wind turbine pitch control system according to claim 1 is characterized in that: Calculation of the pitch motor torque in each segmented pitch angle interval includes: According to the IEC61400-1 standard and the Germanischer Lloyd's GL wind turbine certification guide, the grid power-off working condition of the wind turbine is set, and the emergency pitch retraction simulation calculation is performed for each segmented pitch angle interval. The blade root load data timing file from the rated wind speed to the cut-out wind speed is output, and the emergency pitch retraction and pitch motor side torque root mean square value at each wind speed in each segmented pitch interval is obtained. The obtained pitch motor side torque root mean square value is averaged to obtain the emergency pitch retraction and pitch motor torque value in each segmented pitch angle interval under the grid power-off condition.

6. The method for calculating the energy demand of the backup power supply of the wind turbine pitch control system according to claim 1 is characterized in that: The torque and speed of the pitch motor in each segment are calculated using the following formula: N t =D t ×(60 / 360)×i; Among them, N t It represents the speed of the variable pitch motor in any segment of the wind turbine blade emergency feathering angle range when the power grid is off, D t It represents the pitch speed corresponding to any segment in the emergency feathering angle range of the wind turbine blades when the power grid is off, and i represents the total speed ratio of the pitch system.

7. The method for calculating the energy demand of the backup power supply of the wind turbine pitch control system according to claim 1 is characterized in that: According to the pitch motor torque value and pitch motor speed of each segment, the backup power supply energy in each segment is calculated and determined by the following formula: Among them, B t represents any segment selected from the several segments divided into the emergency feathering angle range of the wind turbine blades when the power grid is off; B t+1 It represents the adjacent segment of any segment selected in the emergency feathering angle range of the wind turbine blades when the power grid is off, and segment B t+1 The angle value of the corresponding propeller angle interval is greater than that of segment B. t The angle value of the corresponding propeller angle range, B t+1 The maximum value of the pitch angle interval corresponding to the segment is less than or equal to 90°, B t The minimum angle value of the pitch angle interval corresponding to the segment is greater than or equal to 0°; t It represents the pitch speed corresponding to any segment selected in the emergency pitch angle range of the wind turbine blades when the power grid is off; E t It represents the energy required for changing the pitch once within the corresponding angle range of any segment selected from the emergency feathering angle range of the wind turbine blades when the power grid is off; T t It represents the motor torque value corresponding to any segment selected in the emergency pitch angle range of the wind turbine blades when the power grid is off; η1 represents the efficiency of the wind turbine pitch reducer; η2 represents the efficiency of the wind turbine pitch motor; η3 represents the efficiency of the wind turbine pitch drive.

8. The method for calculating the energy demand of the backup power supply of the wind turbine pitch control system according to claim 1 is characterized in that: The energy consumed by low voltage ride-through when the wind turbine blades are urgently feathered due to power failure in the power grid is calculated by the following formula: Among them, E z It represents the energy consumed by the wind turbine when the blades are urgently feathered due to a low voltage ride-through for a duration of m. 额 Indicates the rated torque of the wind turbine pitch motor, N z It represents the rated torque of the wind turbine pitch motor and the motor speed at normal pitch speed. m represents the pitch time of the wind turbine during low voltage ride-through.

9. A system for calculating the energy demand of backup power supply of a wind turbine variable pitch system, characterized in that: include: A segmented acquisition module, which is used to divide the wind turbine blade emergency feathering angle range when the power grid is powered off into several segments, so that each segment corresponds to a pitch angle interval, and collect the pitch speed in each segment; A torque and speed calculation module, which is used to calculate the torque and speed of the pitch motor in each segment respectively; A segmented backup power supply energy calculation module, wherein the segmented backup power supply energy calculation module is used to calculate the backup power supply energy in each segment according to the pitch motor torque value and pitch motor speed of each segment; A low voltage ride-through energy calculation module, which is used to calculate the energy consumed by low voltage ride-through when the wind turbine generator set loses power and its blades are urgently feathered; A total energy calculation module is used to sum the backup power supply energy of each segment obtained and the energy consumed by the low voltage ride-through when the wind turbine blades are urgently aligned when the power grid is lost, so as to obtain the total backup power supply energy required for emergency alignment when the wind turbine blades are urgently aligned when the power grid is lost.

10. A wind turbine generator set, characterized in that: The wind turbine generator set is provided with a wind turbine generator set pitch control system backup power supply energy demand calculation system as described in claim 9 above.

Images