Method and system for improving the availability of a wind turbine by means of redundant protection clearance

Abstract

The present invention discloses a method and system for improving the availability of a wind turbine by means of redundant protection of the clearance. It mainly performs redundant control based on dual lidar sensors and simultaneously conducts intelligent control of data verification. By making full use of the correlation of laser in the time axis and space axis for real-time verification, it ensures that under extreme weather or harsh working conditions, the clearance monitoring is reliable and controllable, the clearance of the unit is safe and controllable, and the unit operates safely and stably. The present invention conducts in-depth screening from the data perspective, identifies accurate data at the source, eliminates interference data, and lays a foundation for subsequent clearance control; the present invention effectively verifies the risk of clearance control caused by the loosening of the clearance monitoring system, identifies and anticipates in advance, and seizes the window period for fault handling; the present invention makes full use of the complementarity of the two laser data to ensure the effectiveness of clearance monitoring in real time, effectively identifies the interference of bad weather on the clearance, makes advance judgments and early warnings, improves the availability of the unit, and reduces the misjudgment of faults.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation control, and in particular to a method and system for improving the availability of wind turbines by means of redundant protection of the clearance. Background Art

[0002] With the consideration of the large-scale development of wind turbines and comprehensive aspects such as cost and load, the blades are also developing in the direction of being longer and lighter. Inevitably, the deformation of the blades in large wind turbines is getting larger and larger. In some extreme working conditions, it is easy to have a dangerous distance where the blade is close to the tower wall.

[0003] Currently, mainstream manufacturers also consider adding blade monitoring devices to protect the clearance of the unit and prevent the risk of the blade sweeping the tower. Technologically, there are laser direction, image direction or millimeter wave direction, but mostly lidar is used for distance detection. For whatever technology is used, including lidar technology for distance detection, there may be situations where the visibility decreases in extreme weather, the measured distance is inaccurate, or the monitoring itself becomes loose or fails. This will cause the unit to be in danger, or the unit can only be forced to stop, wasting the good wind energy in vain.

[0004] In existing patent documents, to solve this situation, mainly consider optimizing from the perspective or method of the instrument for measuring distance and the supporting installation structure or measurement method. There is no means of using signal data for in-depth screening, redundant protection control strategy, and effectively verifying and judging the reliability of the clearance monitoring system from the control strategy, so as to reduce the failure rate caused by the clearance of the unit and improve the availability of the unit and the power generation efficiency of the unit on the premise of ensuring the safety of the unit. Summary of the Invention

[0005] The first object of the present invention is to overcome the deficiencies of the prior art and provide a method for improving the availability of wind turbines by means of redundant protection of the clearance. Based on two-beam laser ranging, through data screening, redundant protection, verification and other means, ensure the reliability and safety of the clearance control strategy, thereby improving the availability of the unit.

[0006] The second object of the present invention is to provide a system for improving the availability of wind turbines by means of redundant protection of the clearance.

[0007] The first object of the present invention is achieved by the following technical solution: A method for improving the availability of wind turbines by means of redundant protection of the clearance, which is based on dual lidar sensors for redundant control and simultaneously performs data verification intelligent control, making full use of the correlation of laser in the time axis and space axis for real-time verification, ensuring that in extreme weather or harsh working conditions, the clearance monitoring is reliable and controllable, the clearance of the unit is safe and controllable, and the unit operates safely and stably; it includes the following steps:

[0008] 1) Clearance data screening, the purpose of which is to eliminate mis-triggered data and provide more effective, reliable and accurate data for clearance control;

[0009] 2) Lidar sensor calibration and judgment, through the clearance data calibration of dual lidar sensors:

[0010] a. Spatial calibration:

[0011] Spatial calibration is carried out through the different installation angles of two laser beams, that is, two laser beams with different angles. The different distances S 1 and S 2 are detected, and the corresponding clearance values N 1 and N 2 are calculated according to the blade deformation curve. And N 1 and N 2 are compared in real time. If the difference between the two clearance values is less than b MAX , the spatial calibration passes; otherwise, the spatial calibration fails.

[0012] b. Temporal calibration:

[0013] Temporal calibration is carried out on the time axis through the different time intervals when the blade rotates through the two laser beams. There will be a time misalignment on the time axis when the two laser beams irradiate the blade, which are the time values t 1 and t 2 respectively. And t 1 and t 2 are compared in real time. If the difference between the two time values is less than T MAX , the temporal calibration passes; otherwise, the temporal calibration fails.

[0014] Through the above spatial calibration and temporal calibration, it is possible to judge whether there is a loosening situation in the clearance monitoring system and predict and discover it in advance.

[0015] 3) Control radar selection: Real-time judgment is carried out through the data of two laser beams, and one laser beam is preferentially selected for control. When the dual lidar sensors fail, the unit enters the safety mode; among them, the safety mode means that: the blade angle of the unit becomes relatively larger, and the control method has no clearance risk. Although the power curve has losses, it can reduce the failure rate and ensure the grid connection and power generation of the unit.

[0016] Based on the above steps, the authenticity of the data can be effectively confirmed, and the control based on this data can effectively improve the reliability and accuracy of the clearance control, thereby improving the availability of the unit.

[0017] Furthermore, in step 1), the following screening conditions are added to the data input by the lidar sensor:

[0018] a. The real-time blade angle of the unit is less than DAngleMAX ;

[0019] b. The real-time active power of the unit is greater than P MAX ;

[0020] c. The real-time impeller azimuth angle of the unit is greater than A MIN and less than A MAX ;

[0021] d. The clearance distance is greater than S MIN and less than S MAX ;

[0022] After the above screening, the data of mis-triggering can be eliminated, providing more effective, reliable and accurate data for clearance control.

[0023] Further, in step 3), through real-time judgment of two beams of laser data, one beam of laser is preferentially selected for control, specifically as follows:

[0024] a. Optimize the use of the 1# lidar sensor for control through real-time data;

[0025] b. When the 1# lidar sensor fails or an abnormal situation occurs, switch to the 2# lidar sensor for control, and the control between the two lidar sensors can be switched mutually.

[0026] The second object of the present invention is achieved by the following technical solution: A system for improving the availability of a wind turbine by redundant protection of clearance, which is based on dual lidar sensors for redundant control and simultaneously performs intelligent control of data verification, makes full use of the correlation of laser in the time axis and space axis for real-time verification, ensures that under extreme weather or harsh working conditions, the clearance monitoring is reliable and controllable, the clearance of the unit is safe and controllable, and the unit operates safely and stably; it includes:

[0027] A clearance data screening module, which is used to eliminate the data of mis-triggering and provide more effective, reliable and accurate data for clearance control;

[0028] A sensor verification and judgment module, which verifies the clearance data through dual lidar sensors, including spatial verification and time verification; wherein, the spatial verification means: performing spatial verification through two lasers with different installation angles, that is, two lasers with different angles, detecting different distances S 1 and S 2 , calculating the corresponding clearance values N 1 and N 2 according to the blade deformation curve, and comparing N 1 and N 2 in real time. If the difference between the two clearance values is less than b MAX, the space check passes; otherwise, the space check fails. The time check refers to: performing a check on the time axis by means of the time intervals when the blade rotates through for two laser beams. When the two detected laser beams irradiate the blade, there will be a time misalignment on the time axis, which are time values t 1 and t 2 , and t 1 and t 2 are compared in real time. If the difference between the two time values is less than T MAX , the time check passes; otherwise, the time check fails. Through the above space check and time check, it is possible to determine whether there is a loosening situation in the clearance monitoring system and predict and discover it in advance;

[0029] Control the radar selection module, and make a real-time judgment based on the two laser beam data to preferentially select one laser beam for control. If the dual-laser radar sensor fails, the unit enters the safety mode. Among them, the safety mode refers to: the blade angle of the unit becomes relatively larger, and the control method without clearance risk. There is a loss in the power curve, but it can reduce the failure rate and ensure the grid connection and power generation of the unit.

[0030] Furthermore, in the clearance data screening module, the following screening conditions are added based on the data input by the lidar sensor:

[0031] a. The real-time blade angle of the unit is less than D AngleMAX ;

[0032] b. The real-time active power of the unit is greater than P MAX ;

[0033] c. The real-time azimuth angle of the unit's impeller is greater than A MIN and less than A MAX ;

[0034] d. The clearance distance is greater than S MIN and less than S MAX ;

[0035] After the above screening, the data of mis-triggering can be eliminated, providing more effective, reliable and accurate data for clearance control.

[0036] Furthermore, in the control radar selection module, a real-time judgment is made based on the two laser beam data to preferentially select one laser beam for control, specifically as follows:

[0037] a. Optimize the use of the 1# lidar sensor for control through real-time data;

[0038] b. When the 1# lidar sensor fails or an abnormal situation occurs, switch to the 2# lidar sensor for control, and the control between the two lidar sensors can be switched mutually.

[0039] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0040] 1. Conduct in-depth screening from the data perspective, identify accurate data at the source, effectively filter the data, eliminate interfering data, and lay a foundation for subsequent clearance control;

[0041] 2. Make full use of the correlation of laser in the time axis and space axis for real-time inspection, so as to effectively inspect the risk of clearance control caused by loosening of the clearance monitoring system, identify and predict in advance, and seize the window period for fault handling;

[0042] 3. Make full use of the complementarity of two-beam laser data to ensure the effectiveness of clearance monitoring in real time, effectively identify the interference of bad weather on clearance, make advance judgments and early warnings, improve the availability of the unit, and reduce false fault judgments.

[0043] The following problems existing in the current mainstream clearance control can be solved by the above means:

[0044] 1. Solve the problem of false alarms of clearance faults of the unit under extreme weather conditions;

[0045] 2. Solve the problem that the clearance monitoring system is loose and cannot accurately detect;

[0046] 3. Solve the problem that the clearance control is not user-friendly, resulting in low availability of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic logical flow diagram of the method of the present invention.

[0048] Figure 2 It is a block diagram for screening clearance data.

[0049] Figure 3 It is a spatial calibration diagram (side view of the unit).

[0050] Figure 4 It is a time calibration diagram (front view of the unit).

[0051] Figure 5 It is a control flow chart for lidar selection.

[0052] Figure 6 It is an architecture diagram of the system of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] The present invention will be further described in detail below in conjunction with the embodiments and the drawings, but the embodiments of the present invention are not limited thereto.

[0054] Embodiment 1

[0055] This embodiment discloses a method for improving the availability of a wind turbine by redundant protection of the clearance. This method is based on redundant control using dual lidar sensors and simultaneously performs intelligent control of data verification. It makes full use of the correlation of laser in the time axis and space axis for real-time verification to ensure that under extreme weather or harsh working conditions, the clearance monitoring is reliable and controllable, the clearance of the unit is safe and controllable, and the unit operates safely and stably; as Figure 1 shown, it includes the following steps:

[0056] 1) Clearance data screening. For the data input by the lidar sensor, as Figure 2 shown, add the following screening conditions:

[0057] a. The real-time blade angle D of the unit Angle is less than D AngleMAX ;

[0058] b. The real-time active power P of the unit is greater than P MAX ;

[0059] c. The real-time azimuth angle A of the unit's impeller is greater than A MIN and less than A MAX ;

[0060] d. The clearance detection distance S is greater than S MIN and less than S MAX ;

[0061] After the above screening, the mis-triggered data can be basically eliminated, providing more effective, reliable and accurate data for clearance control.

[0062] 2) Lidar sensor calibration and judgment. Perform clearance data calibration through dual lidar sensors:

[0063] a. Spatial calibration (see Figure 3 shown):

[0064] Perform spatial calibration through two lasers with different installation angles, that is, two lasers with different angles, and detect different distances S 1 and S 2 , calculate the corresponding clearance values N 1 and N 2 according to the blade deformation curve, and compare N 1 and N 2 in real time. If the difference between the two clearance values is less than b MAX , the spatial calibration passes; otherwise, the spatial calibration fails;

[0065] b. Temporal calibration (see Figure 4 shown):

[0066] Calibration on the time axis is performed by two laser beams with different time intervals when the blade rotates through. When the two detected laser beams irradiate the blade, there will be a certain time misalignment on the time axis, which are time values t 1 and t 2 , and t 1 and t 2 are compared in real time. If the difference T’ between the two time values is less than T MAX , the time calibration passes; otherwise, the time calibration fails.

[0067] Through the above spatial calibration and time calibration, it is possible to determine whether there is a loosening situation in the clearance monitoring system, and predict and discover it in advance.

[0068] 3) Control radar selection

[0069] Judgment is made in real time through the data of two laser beams, and one laser beam is preferentially selected for control. As Figure 5 shown, the specific process is as follows:

[0070] a. Optimize the use of the 1# lidar sensor for control through real-time data;

[0071] b. When the 1# radar fails or an abnormal situation occurs, switch to the 2# lidar sensor for control, and the control between the two lidar sensors can be switched mutually;

[0072] When both lidar sensors fail, the unit enters the safety mode; among them, the safety mode means that the blade angle of the unit becomes relatively larger, and there is a control method without clearance risk. Although there is a certain loss in the power curve, it can reduce the failure rate and ensure the grid connection and power generation of the unit.

[0073] Based on the above steps, the authenticity of the data can be effectively confirmed, and the control based on this data can effectively improve the reliability and accuracy of the clearance control, thereby improving the availability of the unit.

[0074] Embodiment 2

[0075] This embodiment discloses a system for improving the availability of a wind turbine through redundant protection of the clearance. The system is based on dual lidar sensors for redundant control and simultaneously performs intelligent control of data verification, making full use of the correlation of lasers on the time axis and space axis for real-time verification to ensure that the clearance monitoring is reliable and controllable, the clearance of the unit is safe and controllable, and the unit operates safely and stably under extreme weather or harsh working conditions; as Figure 6 shown, it includes the following functional modules:

[0076] Clearance data screening module, which is used to eliminate mis-triggered data and provide more effective, reliable and accurate data for clearance control;

[0077] Sensor calibration judgment module, which calibrates the clearance data through dual lidar sensors, including spatial calibration and time calibration; among them, the spatial calibration means: calibrating in space through the installation angles of two laser beams being different, that is, two laser beams with different angles, and detecting different distances S 1 and S 2 , calculating the corresponding clearance values N 1 and N 2 according to the blade deformation curve, and comparing N 1 and N 2 in real time. If the difference between the two clearance values is less than b MAX , the spatial calibration passes; otherwise, the spatial calibration fails. The time calibration means: calibrating on the time axis through the different time intervals when the blade rotates through for two laser beams. There will be a time misalignment on the time axis when the two laser beams irradiate the blade, which are the time values t 1 and t 2 , and comparing t 1 and t 2 in real time. If the difference between the two time values is less than T MAX , the time calibration passes; otherwise, the time calibration fails. Through the above spatial calibration and time calibration, it is possible to judge whether there is a loosening situation in the clearance monitoring system and predict and discover it in advance;

[0078] Control radar selection module, which makes a real-time judgment through the data of two laser beams, preferentially selects one laser beam for control, and if the dual lidar sensors fail, the unit enters the safety mode; among them, the safety mode means: the blade angle of the unit becomes relatively larger, and the control method without clearance risk. There is a loss in the power curve, but it can reduce the failure rate and ensure the grid connection and power generation of the unit.

[0079] Furthermore, in the clearance data screening module, the following screening conditions are added through the data input by the lidar sensor:

[0080] a. The real-time blade angle of the unit is less than D AngleMAX ;

[0081] b. The real-time active power of the unit is greater than P MAX ;

[0082] c. The real-time impeller azimuth angle of the unit is greater than A MIN and less than A MAX ;

[0083] d. The clearance distance is greater than S MIN and less than S MAX ;

[0084] After the above screening, the mis-triggered data can be eliminated, providing more effective, reliable and accurate data for clearance control.

[0085] Furthermore, in the control radar selection module, by real-time judgment of two beams of laser data, one beam of laser is preferentially selected for control, as follows:

[0086] a. Optimize the use of the 1# lidar sensor for control through real-time data;

[0087] b. When the 1# lidar sensor fails or an abnormal situation occurs, switch to the 2# lidar sensor for control, and the control between the two lidar sensors can be switched with each other.

[0088] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A method for improving the availability of a wind turbine by redundant protection of clearance, characterized in that, this method is based on dual lidar sensors for redundant control and simultaneously performs intelligent control of data verification, making full use of the correlation of laser in the time axis and space axis for real-time verification, ensuring that under extreme weather or harsh working conditions, the clearance monitoring is reliable and controllable, the clearance of the unit is safe and controllable, and the unit operates safely and stably; it includes the following steps: 1) Clearance data screening, the purpose of which is to eliminate mis-triggered data and provide more effective, reliable and accurate data for clearance control. By the data input by the lidar sensor, the following screening conditions are added: a. The real-time blade angle of the unit is less than D AngleMAX ; b. The real-time active power of the unit is greater than P MAX ; c. The real-time impeller azimuth angle of the unit is greater than A MIN and less than A MAX ; d. The clearance distance is greater than S MIN and less than S MAX ; After the above screening, mis-triggered data can be eliminated, providing more effective, reliable and accurate data for clearance control; 2) Lidar sensor calibration judgment, through the clearance data calibration of dual lidar sensors: a. Spatial calibration: Spatial calibration is performed by installing two laser beams at different angles, i.e., two laser beams at different angles, and detecting different distances S 1 and S 2 , and the corresponding clearance value N is calculated according to the blade deformation curve 1 and N 2 , and N 1 and N 2 are compared in real time. If the difference between the two clearance values is less than b MAX , the spatial calibration passes; otherwise, the spatial calibration fails b. Time calibration: Time-axis calibration is performed by two laser beams with different time intervals when the blade rotates through. When the two detected laser beams irradiate the blade, there will be a time misalignment on the time axis, which are time values t 1 and t 2 , and t 1 and t 2 are compared in real time. If the difference between the two time values is less than T MAX , the time calibration passes; otherwise, the time calibration fails. Through the above spatial calibration and time calibration, it can be judged whether there is any looseness in the clearance monitoring system, and early prediction and discovery can be made; 3) Control radar selection: Through real-time judgment of the two laser data, one laser is preferentially selected for control. When the dual lidar sensors fail, the unit enters the safety mode; among them, the safety mode means: the blade angle of the unit becomes relatively larger, and the control method without clearance risk, although the power curve has losses, can reduce the failure rate and ensure the grid connection and power generation of the unit; Based on the above steps, the authenticity of the data can be effectively confirmed, and the control based on this data can effectively improve the reliability and accuracy of clearance control, thereby improving the availability of the unit.

2. A method for improving the availability of a wind turbine by redundant protection of clearance according to claim 1, characterized in that, in step 3), through real-time judgment of the two laser data, one laser is preferentially selected for control, specifically as follows: a. Optimize the use of the 1# lidar sensor for control through real-time data; b. When the 1# lidar sensor fails or abnormal conditions occur, switch to the 2# lidar sensor for control, and the control between the two lidar sensors can be switched mutually.

3. A system for improving the availability of a wind turbine by redundant protection of clearance, characterized in that, this system is based on dual lidar sensors for redundant control and simultaneously performs intelligent control of data verification, making full use of the correlation of laser in the time axis and space axis for real-time verification, ensuring that under extreme weather or harsh working conditions, the clearance monitoring is reliable and controllable, the clearance of the unit is safe and controllable, and the unit operates safely and stably; it includes: A clearance data screening module, used to eliminate mis-triggered data and provide more effective, reliable and accurate data for clearance control; The sensor calibration judgment module conducts calibration on the clearance data of the dual lidar sensors, including spatial calibration and temporal calibration. Among them, the spatial calibration means that: spatial calibration is carried out through two lasers with different installation angles, that is, two lasers with different angles, and the detected different distances S 1 and S 2 , and the corresponding clearance values N 1 and N 2 are calculated according to the blade deformation curve, and N 1 and N 2 are compared in real time. If the difference between the two clearance values is less than b MAX , the spatial calibration passes; otherwise, the spatial calibration fails. The temporal calibration means that: temporal calibration is carried out on the time axis by the different time intervals when the two lasers pass through as the blade rotates. There will be a time dislocation on the time axis when the two lasers irradiate the blade, which are the time values t 1 and t 2 , and t 1 and t 2 are compared in real time. If the difference between the two time values is less than T MAX , the temporal calibration passes; otherwise, the temporal calibration fails. Through the above spatial calibration and temporal calibration, it is possible to judge whether there is a loosening situation in the clearance monitoring system and predict and discover it in advance; A control radar selection module, through real-time judgment of the two laser data, preferentially selects one laser for control. When the dual lidar sensors fail, the unit enters the safety mode; among them, the safety mode means: the blade angle of the unit becomes relatively larger, and the control method without clearance risk, although the power curve has losses, can reduce the failure rate and ensure the grid connection and power generation of the unit; In the clearance data screening module, for the data input by the lidar sensor, the following screening conditions are added: a. The real-time blade angle of the unit is less than D AngleMAX ; b. The real-time active power of the unit is greater than P MAX ; c. The real-time impeller azimuth angle of the unit is greater than A MIN and less than A MAX ; d. The clearance distance is greater than S MIN and less than S MAX ; After the above screening, the data with false triggers can be eliminated, providing more effective, reliable and accurate data for clearance control.

4. A system for improving the availability of a wind turbine by redundant protection of clearance according to claim 3, characterized in that in the control radar selection module, through real-time judgment of two beams of laser data, one beam of laser is preferentially selected for control, specifically as follows: a. Use the 1# lidar sensor for control through real-time data optimization; b. When the 1# lidar sensor fails or an abnormal situation occurs, switch to the 2# lidar sensor for control, and the control between the two lidar sensors can be switched mutually.

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