Method and system for monitoring fan impeller unbalance based on millimeter wave radar

Abstract

The application discloses a kind of based on millimeter wave radar monitoring fan impeller unbalance phenomenon method and system, the method is using the strong penetration of millimeter wave detection, millimeter wave radar is installed in the cabin or tower wall of fan, for scanning monitoring blade operating state, and the clearance data collected is transmitted to the main control PLC of fan in real time and is sampled, screened and grouped, obtain the clearance data after grouping of all blades, that is, a group corresponds to the clearance data of a blade, then the clearance data of all blades is average difference value processing, that is, the average value of the clearance data of each blade is calculated, then the difference value of the clearance data of each blade and average value is calculated, compare the difference value of all blades, if the difference value of any blade exceeds the preset alarm threshold, then judge that impeller exists unbalance phenomenon.The application is simple and efficient, safe and reliable, high accuracy, cost reduction, with wider universality, significantly improve the power generation of fan under the premise of protecting the safety of fan.

Description

Technical Field

[0001] This invention relates to the technical field of wind power generation, and in particular to a method, system, storage medium, and computing device for monitoring wind turbine impeller imbalance based on millimeter-wave radar. Background Technology

[0002] Wind power is a clean and renewable energy source, and its core equipment is the wind turbine generator set (also known as a wind turbine, wind turbine unit, wind power generator, etc.). The main working component of a wind turbine is the impeller, which is driven by wind energy, converting wind energy into mechanical energy, and then further into electrical energy. However, impeller imbalance may occur during operation, which can affect the stable operation and service life of the wind turbine. Therefore, monitoring wind turbine impeller imbalance is very important.

[0003] Radar data processing technology is a technique that uses radar to transmit and receive electromagnetic waves, and then analyzes the reflected electromagnetic waves to obtain relevant information about target objects. In the field of wind power generation, clearance radar can be used to monitor the clearance data of wind turbine blades, that is, the distance between the blades and the tower.

[0004] Mechanical equipment monitoring technology is a technique that predicts and prevents equipment failures by monitoring and analyzing the operating status of equipment in real time. In wind turbine monitoring, the balance of the impeller can be determined by analyzing the headroom data of the blades.

[0005] Existing methods for monitoring impeller imbalance primarily involve measuring the impeller's vibration signals and then processing them using algorithms to determine if the impeller is in a balanced state. Additionally, some methods directly measure the impeller's weight distribution to determine imbalance. Recently, a new method has emerged that utilizes changes in the headroom of the three blades to assess impeller balance.

[0006] Existing methods for monitoring impeller imbalance in wind turbines have some problems, such as:

[0007] 1. Currently, a common approach is to install fiber optic load sensors or vibration sensors at the blade root. Based on changes in the load or vibration signals at the blade root, data evaluation and analysis of impeller surface imbalance are performed according to the characteristics of these changes. However, this approach is not only costly and complex to install, but also requires high sensor accuracy and is greatly affected by environmental humidity and temperature. It also requires a relatively complex algorithm evaluation system.

[0008] 2. The method of directly measuring the weight distribution of the impeller is difficult to measure, as it is affected by manpower and equipment. Secondly, it is impossible to predict and judge the imbalance in advance, and the measurement is generally carried out when the impeller imbalance is obvious. Finally, this method cannot be monitored in real time and is greatly affected by external environmental factors such as temperature, wind force, and humidity.

[0009] 3. Chinese invention patent CN117780573A discloses a real-time monitoring method for wind turbine rotor imbalance using multi-data fusion. It deploys video and millimeter-wave equipment and a data processor to effectively and accurately capture the clearance value when the blades pass over the tower through data fusion, thereby identifying the degree of rotor imbalance and implementing real-time monitoring and alarm functions. This solution has considerable feasibility, but it still suffers from high cost and limited applicability. Deploying two types of clearance monitoring equipment for redundant mutual verification to monitor rotor imbalance is costly; in the wave of cost reduction and efficiency improvement, most wind turbines have eliminated rotor encoders and related equipment; this invention requires rotor azimuth information to determine blade position during data processing, limiting its applicability; and the data processing and verification algorithms for the two clearance devices are highly complex. Summary of the Invention

[0010] The primary objective of this invention is to overcome the problems of high cost, low accuracy, low applicability, and non-real-time nature of existing impeller imbalance monitoring methods, and to provide a simple, efficient, safe, reliable, accurate, and cost-effective method for monitoring wind turbine impeller imbalance based on millimeter-wave radar. This method has broader applicability and significantly improves wind turbine power generation while protecting wind turbine safety.

[0011] The second objective of this invention is to provide a system for monitoring wind turbine impeller imbalance based on millimeter-wave radar.

[0012] A third objective of this invention is to provide a storage medium.

[0013] A fourth objective of this invention is to provide a computing device.

[0014] The first objective of this invention is achieved through the following technical solution: a method for monitoring wind turbine impeller imbalance based on millimeter-wave radar. This method utilizes the strong penetrating power of millimeter-wave detection, installing millimeter-wave radar in the nacelle or tower wall of the wind turbine to scan and monitor the blade operating status. The collected clearance data is transmitted in real time to the main control PLC of the wind turbine for sampling, filtering, and grouping, obtaining clearance data after grouping all blades, i.e., one group corresponds to the clearance data of one blade. Then, the clearance data of all blades is averaged and differentially processed, i.e., the average value of the clearance data of each blade is calculated, and then the difference between the clearance data of each blade and the average value is calculated. The differences of all blades are compared. If the difference of any blade exceeds a preset alarm threshold, it is determined that there is an imbalance in the impeller.

[0015] Furthermore, in the main control PLC, the net clearance data is sampled according to the preset sampling rules to obtain initial sample data. During the sampling process, preconditions need to be added, and the wind turbine needs to be in a relatively stable power generation state during the sampling period to ensure the continuity and rationality of the data. Then, the initial sample data is filtered according to the preset filtering rules to avoid the phenomenon of missing points of blades, and the final sample data is obtained.

[0016] Furthermore, the method for monitoring wind turbine impeller imbalance based on millimeter-wave radar includes:

[0017] a. Sampling and filtering of the airspace data;

[0018] The sampling rule adopts the following two conditions:

[0019] ①The current power generation is a specified multiple of the rated power;

[0020] ② The power setting value remains unchanged for a preset time;

[0021] When both conditions of the above sampling rules are met simultaneously, data is sampled at the moment of net clearance change to obtain initial sample data, and then the following filtering rules are executed:

[0022] Based on the characteristics of millimeter-wave radar's clearance data, which is that the data is only updated when a blade is scanned, the clearance data is a stepped data curve that is maintained for a period of time. When the clearance data remains unchanged for a preset time, there may be a gap where no blade is scanned. If a gap exists, the data needs to be resampled until a preset number of consecutive sample data is obtained, which is the final sample data, and stored in array S to ensure that the data in array S is continuous.

[0023] b. Classify and group the final sample data;

[0024] The data is stored in order according to the blade sequence. Without the aid of impeller azimuth angle, the net clearance data corresponding to the specific blade is unknown. The first data stored in array S by default is the net clearance data of the first blade, i.e., the net clearance data of blade 1. At the same time, a preset number of sample data are divided into n groups corresponding to the number of blades to correspond to the net clearance data of all blades.

[0025] c. Perform average difference processing on the grouped net data;

[0026] First, calculate the average clearance data of each blade. Then, calculate the difference between the clearance data of each blade and the average value. Finally, compare the differences of all blades. If the difference of any blade exceeds the preset alarm threshold, it is determined that the impeller is unbalanced and an alarm is output.

[0027] Furthermore, an alarm result will only be output if the impeller is determined to be unbalanced two or three times in a row.

[0028] Furthermore, the airspace data collected by the millimeter-wave radar is converted into a communication method acceptable to the main control PLC through a gateway.

[0029] Furthermore, the millimeter-wave radar transmits the collected airspace data to the main control PLC in real time via the Modbus protocol.

[0030] The second objective of this invention is achieved through the following technical solution: a system for monitoring wind turbine impeller imbalance based on millimeter-wave radar, used to implement the aforementioned method for monitoring wind turbine impeller imbalance based on millimeter-wave radar, comprising:

[0031] Millimeter-wave radar is installed in the nacelle or tower wall of the wind turbine to scan and monitor the operating status of the blades and transmit the collected air clearance data to the main control PLC of the wind turbine in real time.

[0032] The data processing module, based on the main control PLC, samples, filters, and groups the collected clearance data to obtain clearance data for all blades after grouping. That is, each group corresponds to the clearance data of one blade. Then, the clearance data of all blades is averaged and differentiated, that is, the average value of the clearance data of each blade is calculated, and the difference between the clearance data of each blade and the average value is calculated. The differences of all blades are compared. If the difference of any blade exceeds the preset alarm threshold, it is determined that there is an imbalance in the impeller.

[0033] The third objective of this invention is achieved through the following technical solution: a storage medium storing a program, which, when executed by a processor, implements the above-mentioned method for monitoring wind turbine impeller imbalance based on millimeter-wave radar.

[0034] The fourth objective of this invention is achieved through the following technical solution: a computing device, including a processor and a memory for storing processor-executable programs, wherein when the processor executes the program stored in the memory, it implements the above-mentioned method for monitoring wind turbine impeller imbalance based on millimeter-wave radar.

[0035] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0036] 1. Cost reduction and universality: No impeller azimuth information is required. This invention samples and filters the clearance data of millimeter-wave radar, and can analyze the clearance data of all blades of the wind turbine without impeller azimuth information, thereby determining whether the impeller is in a balanced state. Under the current trend of cost reduction, this method is also applicable to units that do not have impeller azimuth equipment installed, and has wider universality.

[0037] 2. Low computational load and strong real-time performance: This invention simplifies the data processing process, reduces the computational load, and improves real-time performance by averaging the difference in the net clearance data. Compared with existing technologies, this invention can detect impeller imbalance more quickly, ensuring the stable operation of the fan.

[0038] 3. High accuracy and reliability: By utilizing the characteristics of millimeter waves, the collected airspace data is not affected by external weather, resulting in high accuracy and reliability of the data source. At the same time, the main control program uses multiple preconditions to filter and eliminate data, ensuring data validity, reducing misjudgments, and further improving the safety and stability of the wind turbine.

[0039] 4. Intelligent and safe: With the trend of cost reduction, the blades, as the main component of wind turbines, are becoming longer and more flexible due to cost reduction. Blade clearance monitoring is also an important auxiliary device for wind turbines. Adding millimeter wave equipment can better monitor blade clearance, as well as monitor whether the impeller is unbalanced, and improve power generation. The diversified use of clearance data is a manifestation of wind turbine intelligence and a guarantee of wind turbine safety.

[0040] 5. Controllability: Monitoring impeller imbalance is a long-term and intermittent task, influenced by external factors such as wind speed, wind direction, and turbulence, as well as the turbine's own pitch mechanism. The blades exhibit different pitch angles and deformations under different wind conditions, leading to irregular changes in blade clearance. This includes the effects of impeller rotation and is the basis for judging impeller imbalance based on blade clearance. However, due to the aforementioned influencing factors, we need to set a sampling time-space during the data sampling phase. Within a stable power generation period, we need to sample a continuous segment of clearance data for data storage and analysis. This sampling action is a controllable function switch; we can periodically switch it on and off to ensure monitoring efficiency and controllability. Attached Figure Description

[0041] Figure 1 This is a flowchart of the method of the present invention.

[0042] Figure 2 This is a schematic diagram of the clearance data transmission between the millimeter-wave radar and the main control PLC.

[0043] Figure 3 This is an architecture diagram of the system of the present invention. Detailed Implementation

[0044] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0045] Example 1

[0046] This embodiment discloses a method for monitoring wind turbine impeller imbalance based on millimeter-wave radar. The method utilizes the strong penetrating power of millimeter-wave detection. Millimeter-wave radar is installed in the nacelle or tower wall of the wind turbine to scan and monitor the blade operating status. The collected clearance data is transmitted in real time to the wind turbine's main control PLC for sampling, filtering, and grouping, obtaining clearance data for all blades in groups (one group corresponds to the clearance data of one blade). Then, the clearance data of all blades is averaged and subtracted, i.e., the average clearance data of each blade is calculated, and the difference between the clearance data of each blade and the average is calculated. The differences of all blades are compared. If the difference of any blade exceeds a preset alarm threshold, it is determined that the impeller is unbalanced. Figure 1 As shown, the specific implementation of this method includes the following steps:

[0047] 1) Use millimeter-wave radar to obtain the clearance data of wind turbine blades.

[0048] In this step, we use millimeter-wave radar, a common wind turbine monitoring device. Depending on the installation location, it generally comes in two types: nacelle-type and tower-type. Regardless of the type, it can effectively acquire real-time air clearance data from the wind turbine. This data is then converted by a gateway into a communication method acceptable to the main control PLC (such as the Modbus protocol) and transmitted to the main control PLC located at the tower base. Figure 2 As shown.

[0049] 2) Sampling and filtering of the airspace data.

[0050] In this step, we start sampling according to preset sampling rules. When the conditions meet the preset sampling rules, we obtain initial sample data. The rules are designed to obtain stable headroom data and avoid situations where wind turbine power is limited or large wind condition changes cause excessive or frequent turbine pitch control, which could affect the analysis results. Specific rules can be found below:

[0051] ①The current power generation is a specified multiple of the rated power;

[0052] ② The power setting value remains unchanged for a preset time;

[0053] When both conditions of the above sampling rules are met simultaneously, data is sampled at the moment of net clearance change to obtain initial sample data, and then the following filtering rules are executed:

[0054] Based on the characteristics of millimeter-wave radar's clearance data, which is that data is only updated when a blade is scanned, the clearance data is a stepped data curve that is maintained for a period of time. When the clearance data remains unchanged for 3 seconds, there may be a gap where no blade is scanned. If a gap exists, the data needs to be resampled until 90 consecutive sample data (30 revolutions of the impeller) are obtained, which is the final sample data. This data is stored in array S to ensure that the data in array S is continuous.

[0055] 3) Classify and group the final sample data.

[0056] The data is stored in the order of blade 1, blade 2, blade 3, blade 1, blade 2, blade 3... Without the aid of impeller azimuth angle for judgment, and without knowing the specific clearance data corresponding to each blade, we default to storing the first data in array S as the clearance data for blade 1. In this case, the 90 sample data are divided into three groups, namely S1, S2, and S3, corresponding to the clearance data for blade 1, blade 2, and blade 3, respectively.

[0057] 4) Perform average difference processing on the net data after grouping.

[0058] First, calculate the average clearance data of each blade. Then, calculate the difference between the clearance data of each blade and the average value. Finally, compare the differences of all blades. If the difference of any blade exceeds the preset alarm threshold, it is determined that the impeller is unbalanced and an alarm is output.

[0059] In summary, the method described in this embodiment, through sampling using preset rules, essentially ensures the stability of the sample data. Furthermore, by considering the time condition of constant clearance data during the sampling process—the characteristic of millimeter-wave radar clearance data is that data is only updated when a blade is scanned, meaning the clearance data is a stepped data curve maintained for a certain period. If the data remains unchanged for more than a certain time, there may be missed points where blades were not scanned. This sampling and filtering method can ensure the continuity and reliability of the sample data even without considering the impeller azimuth angle.

[0060] In addition, the preset rules can also add control over the monitoring time and frequency. An alarm result will only be output if the impeller is found to be unbalanced after two or three consecutive determinations, thereby effectively reducing the possibility of false judgments and improving the reliability and stability of wind turbine safety monitoring.

[0061] Example 2

[0062] This embodiment discloses a system for monitoring wind turbine impeller imbalance based on millimeter-wave radar, used to implement the method for monitoring wind turbine impeller imbalance based on millimeter-wave radar described in Embodiment 1, such as... Figure 3As shown, it includes:

[0063] Millimeter-wave radar is installed in the nacelle or tower wall of the wind turbine to scan and monitor the operating status of the blades and transmit the collected air clearance data to the main control PLC of the wind turbine in real time.

[0064] The data processing module, based on the main control PLC, samples, filters, and groups the collected clearance data to obtain clearance data for all blades after grouping. That is, each group corresponds to the clearance data of one blade. Then, the clearance data of all blades is averaged and differentiated, that is, the average value of the clearance data of each blade is calculated, and the difference between the clearance data of each blade and the average value is calculated. The differences of all blades are compared. If the difference of any blade exceeds the preset alarm threshold, it is determined that there is an imbalance in the impeller.

[0065] Example 3

[0066] This embodiment discloses a storage medium storing a program. When the program is executed by a processor, it implements the method for monitoring wind turbine impeller imbalance based on millimeter-wave radar as described in Embodiment 1.

[0067] The storage medium in this embodiment can be a disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), USB flash drive, portable hard drive, etc.

[0068] Example 4

[0069] This embodiment discloses a computing device, including a processor and a memory for storing processor-executable programs. When the processor executes the program stored in the memory, it implements the method for monitoring wind turbine impeller imbalance based on millimeter-wave radar as described in Embodiment 1.

[0070] The computing device described in this embodiment may be a desktop computer, laptop computer, smartphone, PDA handheld terminal, tablet computer, programmable logic controller (PLC), or other terminal device with processor function.

[0071] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for monitoring wind turbine impeller imbalance based on millimeter-wave radar, characterized in that, This method utilizes the strong penetrating power of millimeter-wave radar. Millimeter-wave radar is installed in the nacelle or tower wall of the wind turbine to scan and monitor the blade operating status. The collected clearance data is transmitted in real time to the wind turbine's main control PLC for sampling, filtering, and grouping. This yields clearance data for all blades grouped, with each group corresponding to the clearance data of one blade. Then, the clearance data of all blades is averaged and subtracted, meaning the average clearance data for each blade is calculated, and the difference between each blade's clearance data and the average is calculated. The differences across all blades are compared. If the difference for any blade exceeds a preset alarm threshold, an impeller imbalance is determined. This includes: a. Sampling and filtering of the airspace data; The sampling rule adopts the following two conditions: The current power generation capacity is a specified multiple of the rated power; The power setting remains unchanged for a preset time. When both conditions of the above sampling rules are met simultaneously, data is sampled at the moment of net clearance change to obtain initial sample data, and then the following filtering rules are executed: Based on the characteristics of millimeter-wave radar's clearance data, which is that the data is only updated when a blade is scanned, the clearance data is a stepped data curve that is maintained for a period of time. When the clearance data remains unchanged for a preset time, there may be a gap where no blade is scanned. If a gap exists, the data needs to be resampled until a preset number of consecutive sample data is obtained, which is the final sample data, and stored in array S to ensure that the data in array S is continuous. b. Classify and group the final sample data; The data is stored in order according to the blade sequence. Without the aid of impeller azimuth angle, the net clearance data corresponding to the specific blade is unknown. The first data stored in array S by default is the net clearance data of the first blade, i.e., the net clearance data of blade 1. At the same time, a preset number of sample data are divided into n groups corresponding to the number of blades to correspond to the net clearance data of all blades. c. Perform average difference processing on the grouped net data; First, calculate the average clearance data of each blade. Then, calculate the difference between the clearance data of each blade and the average value. Finally, compare the differences of all blades. If the difference of any blade exceeds the preset alarm threshold, it is determined that the impeller is unbalanced and an alarm is output.

2. The method for monitoring wind turbine impeller imbalance based on millimeter-wave radar according to claim 1, characterized in that, In the main control PLC, the net clearance data is sampled according to the preset sampling rules to obtain the initial sample data. During the sampling process, a precondition needs to be added: the wind turbine needs to be in a relatively stable power generation state during the sampling period to ensure the continuity and rationality of the data. Then, the initial sample data is filtered according to the preset filtering rules to avoid the phenomenon of missing points of blades, and the final sample data is obtained.

3. The method for monitoring wind turbine impeller imbalance based on millimeter-wave radar according to claim 1, characterized in that, An alarm will only be output if the impeller is determined to be unbalanced two or three times in a row.

4. The method for monitoring wind turbine impeller imbalance based on millimeter-wave radar according to claim 1, characterized in that, The airspace data collected by the millimeter-wave radar is converted into a communication method that the main control PLC can accept through the gateway.

5. The method for monitoring wind turbine impeller imbalance based on millimeter-wave radar according to claim 4, characterized in that, The millimeter-wave radar transmits the collected airspace data to the main control PLC in real time via the Modbus protocol.

6. A system for monitoring wind turbine impeller imbalance based on millimeter-wave radar, characterized in that, The method for monitoring wind turbine impeller imbalance based on millimeter-wave radar according to any one of claims 1 to 5 includes: Millimeter-wave radar is installed in the nacelle or tower wall of the wind turbine to scan and monitor the operating status of the blades and transmit the collected air clearance data to the main control PLC of the wind turbine in real time. The data processing module, based on the main control PLC, samples, filters, and groups the collected clearance data to obtain clearance data for all blades after grouping. That is, each group corresponds to the clearance data of one blade. Then, the clearance data of all blades is averaged and differentiated, that is, the average value of the clearance data of each blade is calculated, and the difference between the clearance data of each blade and the average value is calculated. The differences of all blades are compared. If the difference of any blade exceeds the preset alarm threshold, it is determined that there is an imbalance in the impeller.

7. A storage medium storing a program, characterized in that, When the program is executed by the processor, it implements the method for monitoring wind turbine impeller imbalance based on millimeter-wave radar as described in any one of claims 1 to 5.

8. A computing device, comprising a processor and a memory for storing a processor-executable program, characterized in that, When the processor executes the program stored in the memory, it implements the method for monitoring wind turbine impeller imbalance based on millimeter-wave radar as described in any one of claims 1 to 5.

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