A wind turbine unit health state evaluation and early warning system

Abstract

The application discloses a wind turbine health state evaluation and early warning system, and relates to the field of wind turbine operation monitoring and health state evaluation, comprising: a data acquisition module, which is used for acquiring wind turbine energy analysis sequences; a rotor energy determination module, which is used for determining wind energy input values and rotor captured energy values; a transmission energy determination module, which is used for determining main shaft transmission energy values, gearbox transmission energy values, generator conversion energy values and grid-connected output energy values; an energy flow conversion construction module, which is used for constructing energy flow conversion links of target wind turbines; an energy residual determination module, which is used for determining energy residual values; a degradation link determination module, which is used for determining energy loss contribution values of each energy flow conversion link and determining corresponding degradation links of target wind turbines; and an early warning output module, which is used for outputting health state early warning results. The application realizes wind turbine health early warning by utilizing energy flow conversion link analysis, and has the advantages of high positioning accuracy and high reliability.

Description

Technical Field

[0001] This invention relates to the field of wind turbine operation monitoring and health status assessment, and in particular to a wind turbine health status assessment and early warning system. Background Technology

[0002] During long-term operation, wind turbine components such as the rotor, main shaft, gearbox, generator, and grid-connected output may experience health degradation due to load fluctuations, component wear, and changes in operating conditions. Existing wind turbine health monitoring typically relies on wind speed, power, vibration, temperature, or alarm records to determine the condition and outputs early warning results through threshold comparisons or single trend analysis.

[0003] However, existing technologies often focus on external operational phenomena, making it difficult to identify the sources of energy loss in the continuous energy flow process from wind energy input, turbine capture, mechanical transmission, power generation conversion, and grid connection output. When energy fluctuations occur simultaneously in multiple stages, existing methods struggle to quantify the energy loss contribution of each energy flow link, leading to inaccurate location of degradation links, insufficient reliability of health degradation assessment values, and easily delayed or misjudged health status warnings. Summary of the Invention

[0004] One objective of this invention is to propose a wind turbine health status assessment and early warning system. This invention utilizes energy flow link analysis to achieve wind power health early warning, and has the advantages of accurate positioning and high reliability.

[0005] A wind turbine health status assessment and early warning system according to an embodiment of the present invention includes:

[0006] The data acquisition module is used to acquire wind condition monitoring data, rotor operation data, mechanical transmission data, power generation conversion data and grid connection output data of the target wind turbine during operation, perform preprocessing, and obtain the wind turbine energy analysis sequence.

[0007] The rotor energy determination module is used to determine the wind energy input value and rotor captured energy value of the target wind turbine based on the wind turbine energy analysis sequence.

[0008] The energy transfer determination module is used to determine the main shaft energy transfer value, gearbox energy transfer value, generator conversion energy value and grid-connected output energy value of the target wind turbine based on the wind turbine energy analysis sequence.

[0009] The energy flow construction module is used to construct the energy flow link of the target wind turbine based on the wind energy input value, the rotor captured energy value, the main shaft transmitted energy value, the gearbox transmitted energy value, the generator converted energy value, and the grid-connected output energy value.

[0010] The energy residual determination module is used to determine the energy residual value for each energy flow link;

[0011] The degradation link determination module is used to perform discrete wavelet transform and Hilbert transform on the energy residual values ​​corresponding to each energy flow link, extract residual growth components, residual mutation components and residual envelope growth amount, and combine duration and residual ratio to determine the energy loss contribution value of each energy flow link, and determine the degradation link corresponding to the target wind turbine.

[0012] The early warning output module is used to generate a health degradation assessment value for the target wind turbine based on the energy residual value, energy loss contribution value and growth trend corresponding to the degradation link, and output the health status early warning result.

[0013] Optionally, the wind condition monitoring data is data characterizing the external wind energy input conditions of the target wind turbine, the rotor operation data is data characterizing the process of the target wind turbine rotor capturing wind energy, the mechanical transmission data is data characterizing the transmission of wind energy in the mechanical transmission link after being converted by the rotor, the power generation conversion data is data characterizing the process of mechanical energy being converted into electrical energy by the generator, and the grid connection output data is data characterizing the output of electrical energy from the target wind turbine to the grid.

[0014] Optionally, the preprocessing includes time alignment, anomaly removal, and missing information completion.

[0015] Optionally, the impeller energy determination module includes:

[0016] Read the wind condition monitoring data and rotor operation data corresponding to each time position from the wind turbine energy analysis sequence;

[0017] Based on wind condition monitoring data and the swept area of ​​the target wind turbine, the wind energy input value of the target wind turbine at each time location is determined;

[0018] Determine the rotor capture coefficient of the target wind turbine at each time position based on rotor operating data;

[0019] Based on the wind energy input value and the rotor capture coefficient, the rotor capture energy value of the target wind turbine at each time position is determined.

[0020] Optionally, the energy transfer determination module includes:

[0021] Mechanical transmission data, power generation conversion data, and grid-connected output data at each time point are read from the wind turbine energy analysis sequence.

[0022] Based on the mechanical transmission data and the time interval between adjacent time positions, determine the main shaft transmission energy value and gearbox transmission energy value of the target wind turbine at each time position;

[0023] Based on the generator output power data in the power generation conversion data and the time interval between adjacent time positions, determine the generator conversion energy value of the target wind turbine at each time position;

[0024] Based on the grid-connected power data in the grid-connected output data and the time interval between adjacent time locations, the grid-connected output energy value of the target wind turbine at each time location is determined.

[0025] Optionally, the energy transfer construction module includes:

[0026] According to each time position, the wind energy input value is determined as the input energy value of the rotor capture link, and the rotor capture energy value is determined as the output energy value of the rotor capture link;

[0027] The impeller capture energy value is determined as the input energy value of the main shaft transmission link, and the main shaft transmission energy value is determined as the output energy value of the main shaft transmission link.

[0028] The spindle transmits energy as the input energy value of the gearbox drive link, and the gearbox transmits energy as the output energy value of the gearbox drive link.

[0029] The energy value transmitted by the gearbox is determined as the input energy value of the generator conversion link, and the energy value converted by the generator is determined as the output energy value of the generator conversion link.

[0030] The generator conversion energy value is determined as the input energy value of the grid-connected output link, and the grid-connected output energy value is determined as the output energy value of the grid-connected output link;

[0031] Based on the sequential connection relationship of the impeller capture link, main shaft transmission link, gearbox transmission link, generator conversion link and grid-connected output link, construct the energy flow link corresponding to the target wind turbine.

[0032] Optionally, the energy residual determination module includes:

[0033] In the energy flow chain, the input energy value and output energy value corresponding to the impeller capture chain, main shaft transmission chain, gearbox transmission chain, generator conversion chain and grid-connected output chain are read according to each time position;

[0034] For the wind energy input value and the rotor captured energy value of the rotor capture link, determine the corresponding energy residual value of the rotor capture link;

[0035] For the impeller capture energy value and the main shaft transmission energy value of the main shaft transmission link, determine the corresponding energy residual value of the main shaft transmission link;

[0036] For the spindle energy value and gearbox energy value of the gearbox transmission link, determine the corresponding energy residual value of the gearbox transmission link;

[0037] For the gearbox-transmitted energy value and the generator-converted energy value in the generator conversion link, determine the corresponding energy residual value of the generator conversion link;

[0038] For the generator conversion energy value and grid-connected output energy value of the grid-connected output link, determine the corresponding energy residual value of the grid-connected output link.

[0039] Optionally, the degradation link determination module includes:

[0040] The energy residual values ​​corresponding to the impeller capture link, main shaft transmission link, gearbox transmission link, generator conversion link and grid-connected output link are read according to the continuous time position.

[0041] Perform discrete wavelet transform on the energy residual values ​​corresponding to each energy flow link to decompose them into low-frequency and high-frequency residual components;

[0042] The discrete wavelet transform uses the db4 wavelet from the Daubechies wavelet family as the preset wavelet basis, and the preset decomposition level is set to four levels.

[0043] The residual growth component is determined based on the numerical changes of the low-frequency component of the residual at continuous time positions, and the residual mutation component is determined based on the amplitude changes of the high-frequency component of the residual at continuous time positions.

[0044] Perform Hilbert transform on the energy residual values ​​corresponding to each energy flow link to obtain the residual envelope value, and determine the residual envelope growth based on the changes in the residual envelope value at continuous time positions;

[0045] The duration of each energy flow link is determined based on the length of time during which the energy residual value continues to increase at continuous time positions.

[0046] The energy residual values ​​corresponding to each energy transfer link are summed to obtain the cumulative energy residual value of the whole machine in the section, and the residual ratio corresponding to each energy transfer link is calculated.

[0047] Based on the residual growth component, residual mutation component, residual envelope growth amount, duration, and residual ratio, the energy loss contribution value corresponding to each energy flow link is determined;

[0048] The energy flow path that contributes the most to energy loss is identified as the degradation path corresponding to the target wind turbine.

[0049] Optionally, the generation of the energy loss contribution value includes:

[0050] Read the residual growth component, residual mutation component, residual envelope growth amount, duration and residual ratio corresponding to each energy flow link;

[0051] The residual growth component, residual mutation component, residual envelope growth amount, duration and residual ratio of each energy flow link are normalized respectively;

[0052] The energy loss contribution value corresponding to each energy flow link is determined by weighted summation of the normalized residual growth component, residual mutation component, residual envelope growth amount, duration and residual ratio.

[0053] Optionally, the early warning output module includes:

[0054] Read the energy residual value and energy loss contribution value of the degraded link;

[0055] Calculate the overall fitting slope of the energy residual value of the degradation link as a function of time position, and determine it as the growth trend of the degradation link at continuous time positions;

[0056] The energy residual values ​​of the degradation links are accumulated, and the accumulated energy residual values, energy loss contribution values ​​and growth trends are normalized respectively, and the health degradation assessment values ​​of the target wind turbine are generated.

[0057] The health degradation assessment value is compared with the preset health warning threshold. When the health degradation assessment value is less than the preset health warning threshold, the normal operation result is output.

[0058] When the health degradation assessment value is greater than or equal to the preset health warning threshold, the health status warning result is output.

[0059] The beneficial effects of this invention are:

[0060] This invention acquires wind condition monitoring data, rotor operation data, mechanical transmission data, power generation conversion data, and grid-connected output data of a target wind turbine during operation through a data acquisition module. After preprocessing, an energy analysis sequence for the wind turbine is obtained, enabling correlated analysis of the external wind energy input, rotor capture process, mechanical transmission process, power generation conversion process, and grid-connected output process of the target wind turbine at a unified time point. Compared to methods that rely solely on single power, temperature, vibration, or alarm records, this invention establishes a more complete health status assessment foundation based on the energy flow process of the wind turbine, improving the ability of operational data to characterize the health degradation process.

[0061] This invention constructs energy flow links based on wind energy input, impeller capture energy, main shaft transmission energy, gearbox transmission energy, generator conversion energy, and grid-connected output energy. For each energy flow link, an energy residual value is determined, ensuring that the impeller capture link, main shaft transmission link, gearbox transmission link, generator conversion link, and grid-connected output link all have clearly defined input energy values, output energy values, and energy loss characteristics. This allows for the assessment of overall machine health degradation issues by breaking them down into specific energy flow links, avoiding the problem of failing to pinpoint the source of degradation when only judging abnormalities based on a decrease in overall machine output power.

[0062] This invention further applies discrete wavelet transform and Hilbert transform to the energy residual values ​​corresponding to each energy transfer link, extracting residual growth components, residual abrupt change components, and residual envelope growth. Combined with duration and residual proportion, the energy loss contribution value corresponding to each energy transfer link is determined. Through the above processing, the energy loss contribution value can simultaneously reflect the low-frequency continuous growth of the energy residual, high-frequency local abrupt changes, continuous envelope rise, continuous increase duration, and overall system proportion, thereby reducing the impact of short-term wind fluctuations, measurement disturbances, and local anomalies on the judgment results, and improving the accuracy and stability of degraded link determination.

[0063] This invention generates a health degradation assessment value based on the energy residual value, energy loss contribution value, and growth trend corresponding to the degradation link, and outputs a health status early warning result. This result not only reflects whether the target wind turbine has a health degradation risk, but also provides the degradation link name, health degradation assessment value, and corresponding inspection prompts. This provides a basis for maintenance personnel to focus on inspecting the impeller, main shaft, gearbox, generator, or grid-connected output links, thereby improving the reliability, location, and engineering feasibility of wind turbine health status assessment and early warning. Attached Figure Description

[0064] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0065] Figure 1 This is a schematic diagram of the structure of a wind turbine health status assessment and early warning system proposed in this invention;

[0066] Figure 2 This is a trend diagram of the energy residual of the gearbox transmission link in a wind turbine health status assessment and early warning system proposed in this invention. Detailed Implementation

[0067] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0068] refer to Figure 1 A wind turbine health status assessment and early warning system, comprising:

[0069] The data acquisition module is used to acquire wind condition monitoring data, rotor operation data, mechanical transmission data, power generation conversion data and grid connection output data of the target wind turbine during operation, perform preprocessing, and obtain the wind turbine energy analysis sequence.

[0070] The rotor energy determination module is used to determine the wind energy input value and rotor captured energy value of the target wind turbine based on the wind turbine energy analysis sequence.

[0071] The energy transfer determination module is used to determine the main shaft energy transfer value, gearbox energy transfer value, generator conversion energy value and grid-connected output energy value of the target wind turbine based on the wind turbine energy analysis sequence.

[0072] The energy flow construction module is used to construct the energy flow link of the target wind turbine based on the wind energy input value, the rotor captured energy value, the main shaft transmitted energy value, the gearbox transmitted energy value, the generator converted energy value, and the grid-connected output energy value.

[0073] The energy residual determination module is used to determine the energy residual value for each energy flow link;

[0074] The degradation link determination module is used to perform discrete wavelet transform and Hilbert transform on the energy residual values ​​corresponding to each energy flow link, extract residual growth components, residual mutation components and residual envelope growth amount, and combine duration and residual ratio to determine the energy loss contribution value of each energy flow link, and determine the degradation link corresponding to the target wind turbine.

[0075] The early warning output module is used to generate a health degradation assessment value for the target wind turbine based on the energy residual value, energy loss contribution value and growth trend corresponding to the degradation link, and output the health status early warning result.

[0076] In this embodiment, wind condition monitoring data is used to characterize the external wind energy input conditions of the target wind turbine, including wind speed data, wind direction data, and air density data. Rotor operation data is used to characterize the wind energy capture process of the target wind turbine rotor, including rotor speed data and blade pitch angle data. Mechanical transmission data is used to characterize the transmission of wind energy in the mechanical transmission link after being converted by the rotor, including main shaft torque data, main shaft speed data, gearbox input torque data, and gearbox output torque data. Power generation conversion data is used to characterize the process of mechanical energy being converted into electrical energy by the generator, including generator output power data. Grid-connected output data is used to characterize the output of electrical energy from the target wind turbine to the grid, including grid-connected power data. Gearbox input torque data is the torque data entering the low-speed end of the gearbox from the main shaft side of the wind turbine, and gearbox output torque data is the torque data output from the high-speed end of the gearbox to the generator side.

[0077] In this embodiment, preprocessing includes time alignment, anomaly removal, and missing data completion.

[0078] In this embodiment, the impeller energy determination module includes:

[0079] Read the wind condition monitoring data and rotor operation data corresponding to each time position from the wind turbine energy analysis sequence;

[0080] Based on wind condition monitoring data and the swept area of ​​the target wind turbine, the wind energy input value of the target wind turbine at each time location is determined;

[0081] Determine the rotor capture coefficient of the target wind turbine at each time position based on rotor operating data;

[0082] The wind energy input value is the amount of wind energy entering the target wind turbine rotor sweeping area, determined based on wind condition monitoring data at the corresponding time position. The rotor capture coefficient is the proportion of energy actually captured by the rotor from the wind energy input value, determined based on rotor operation data at the corresponding time position.

[0083] Based on the wind energy input value and the rotor capture coefficient, the rotor capture energy value of the target wind turbine at each time position is determined.

[0084] In this embodiment, the energy transfer determination module includes:

[0085] Mechanical transmission data, power generation conversion data, and grid-connected output data at each time point are read from the wind turbine energy analysis sequence.

[0086] Based on the mechanical transmission data and the time interval between adjacent time positions, determine the main shaft transmission energy value and gearbox transmission energy value of the target wind turbine at each time position;

[0087] Based on the generator output power data in the power generation conversion data and the time interval between adjacent time positions, determine the generator conversion energy value of the target wind turbine at each time position;

[0088] Based on the grid-connected power data in the grid-connected output data and the time interval between adjacent time positions, determine the grid-connected output energy value of the target wind turbine at each time position;

[0089] The main shaft transmitted energy value is the mechanical energy transmitted by the target wind turbine through the main shaft to the downstream mechanical transmission link at the corresponding time position. It is used to characterize the mechanical transmission level after the rotor captures energy into the main shaft. The gearbox transmitted energy value is the mechanical energy transmitted by the target wind turbine to the generator side through the gearbox transmission link at the corresponding time position. It is used to characterize the mechanical energy transmission level in the gearbox transmission link. The generator conversion energy value is the electrical energy generated by the generator output power of the target wind turbine at the corresponding time position. It is used to characterize the level of mechanical energy converted into electrical energy by the generator. The grid-connected output energy value refers to the electrical energy generated by the grid-connected power of the target wind turbine and output to the grid at the corresponding time position. It is used to characterize the level of electrical energy actually output by the target wind turbine to the grid.

[0090] In this embodiment, the energy flow construction module includes:

[0091] According to each time position, the wind energy input value is determined as the input energy value of the rotor capture link, and the rotor capture energy value is determined as the output energy value of the rotor capture link;

[0092] The impeller capture energy value is determined as the input energy value of the main shaft transmission link, and the main shaft transmission energy value is determined as the output energy value of the main shaft transmission link.

[0093] The spindle transmits energy as the input energy value of the gearbox drive link, and the gearbox transmits energy as the output energy value of the gearbox drive link.

[0094] The energy value transmitted by the gearbox is determined as the input energy value of the generator conversion link, and the energy value converted by the generator is determined as the output energy value of the generator conversion link.

[0095] The generator conversion energy value is determined as the input energy value of the grid-connected output link, and the grid-connected output energy value is determined as the output energy value of the grid-connected output link;

[0096] The impeller capture link is the energy conversion relationship between the wind energy input value and the impeller capture energy value, used to characterize the process of the target wind turbine impeller capturing energy from external wind energy. The main shaft transmission link is the energy transfer relationship between the impeller capture energy value and the main shaft transmission energy value, used to characterize the process of the impeller capture energy being transferred through the main shaft to the subsequent mechanical transmission links. The gearbox transmission link is the energy transfer relationship between the main shaft transmission energy value and the gearbox transmission energy value, used to characterize the process of mechanical energy being transferred to the generator side through the gearbox transmission links. The generator conversion link is the energy conversion relationship between the gearbox transmission energy value and the generator conversion energy value, used to characterize the process of mechanical energy being converted into electrical energy by the generator. The grid-connected output link is the energy output relationship between the generator conversion energy value and the grid-connected output energy value, used to characterize the process of the target wind turbine outputting the electrical energy converted by the generator to the power grid.

[0097] By dividing the energy transfer process of the target wind turbine into the rotor capture link, main shaft transmission link, gearbox drive link, generator conversion link, and grid-connected output link, the originally continuous energy conversion process of the entire turbine can be broken down into multiple analytical links with clearly defined input and output energy values. The rotor capture link corresponds to the relationship between the wind energy input value and the rotor capture energy value; the main shaft transmission link corresponds to the relationship between the rotor capture energy value and the main shaft transmission energy value; the gearbox drive link corresponds to the relationship between the main shaft transmission energy value and the gearbox transmission energy value; the generator conversion link corresponds to the relationship between the gearbox transmission energy value and the generator conversion energy value; and the grid-connected output link corresponds to the relationship between the generator conversion energy value and the grid-connected output energy value. This division allows for clear link boundaries to define the energy changes of the target wind turbine at each time point, facilitating the subsequent calculation of the energy residual values ​​corresponding to each link.

[0098] Construct the energy transfer links corresponding to the target wind turbine according to the sequential connection relationship of the impeller capture link, main shaft transmission link, gearbox transmission link, generator conversion link and grid-connected output link;

[0099] The sequential connection relationship between the rotor capture link, main shaft transmission link, gearbox transmission link, generator conversion link, and grid-connected output link represents the energy transmission in the target wind turbine unit in the following order: wind energy input value, rotor capture energy value, main shaft transmission energy value, gearbox transmission energy value, generator conversion energy value, and grid-connected output energy value. Specifically, the rotor capture link takes wind energy input as input and rotor capture energy value as output; the main shaft transmission link takes rotor capture energy as input and main shaft transmission energy value as output; the gearbox transmission link takes main shaft transmission energy as input and gearbox transmission energy value as output; the generator conversion link takes gearbox transmission energy as input and generator conversion energy value as output; and the grid-connected output link takes generator conversion energy value as input and grid-connected output energy value as output.

[0100] In this embodiment, the energy residual determination module includes:

[0101] In the energy flow chain, the input energy value and output energy value corresponding to the impeller capture chain, main shaft transmission chain, gearbox transmission chain, generator conversion chain and grid-connected output chain are read according to each time position;

[0102] For the wind energy input value and the rotor captured energy value of the rotor capture link, determine the corresponding energy residual value of the rotor capture link;

[0103] For the impeller capture energy value and the main shaft transmission energy value of the main shaft transmission link, determine the corresponding energy residual value of the main shaft transmission link;

[0104] For the spindle energy value and gearbox energy value of the gearbox transmission link, determine the corresponding energy residual value of the gearbox transmission link;

[0105] For the gearbox-transmitted energy value and the generator-converted energy value in the generator conversion link, determine the corresponding energy residual value of the generator conversion link;

[0106] For the generator conversion energy value and grid-connected output energy value of the grid-connected output link, determine the corresponding energy residual value of the grid-connected output link;

[0107] The energy residual value corresponding to the impeller capture link is used to characterize the energy difference between the wind energy input value and the impeller capture energy value, reflecting the degree of energy loss in the process of the target wind turbine impeller capturing wind energy. The energy residual value corresponding to the main shaft transmission link is used to characterize the energy difference between the impeller capture energy value and the main shaft transmission energy value, reflecting the degree of energy loss in the process of the impeller capture energy being transmitted through the main shaft. The energy residual value corresponding to the gearbox transmission link is used to characterize the energy difference between the main shaft transmission energy value and the gearbox transmission energy value, reflecting the degree of energy loss in the gearbox transmission link. The energy residual value corresponding to the generator conversion link is used to characterize the energy difference between the gearbox transmission energy value and the generator conversion energy value, reflecting the degree of energy loss in the process of mechanical energy being converted into electrical energy by the generator. The energy residual value corresponding to the grid-connected output link is used to characterize the energy difference between the generator conversion energy value and the grid-connected output energy value, reflecting the degree of energy loss in the process of the target wind turbine outputting electrical energy to the grid.

[0108] In this embodiment, the degradation link determination module includes:

[0109] The energy residual values ​​corresponding to the impeller capture link, main shaft transmission link, gearbox transmission link, generator conversion link and grid-connected output link are read according to the continuous time position.

[0110] Perform discrete wavelet transform on the energy residual values ​​corresponding to each energy flow link to decompose them into low-frequency and high-frequency residual components;

[0111] The discrete wavelet transform uses the db4 wavelet from the Daubechies wavelet family as the preset wavelet basis, and the preset decomposition level is set to four levels.

[0112] In this embodiment, the energy residual values ​​corresponding to the impeller capture link, the main shaft transmission link, the gearbox drive link, the generator conversion link, and the grid-connected output link are used as processing objects. The energy residual values ​​of the same energy flow link at continuous time positions are arranged in chronological order to form a residual time series for the corresponding link. The db4 wavelet from the Daubechies wavelet family is selected as the preset wavelet basis, and the preset decomposition level is set to four levels. The low-pass and high-pass filters corresponding to the db4 wavelet are used to perform the first-level decomposition of the residual time series, obtaining the first-level approximation coefficients and the first-level detail coefficients. The first-level approximation coefficients are then further decomposed into second-level approximation coefficients and second-level detail coefficients. The third-level approximation coefficients, third-level detail coefficients, fourth-level approximation coefficients, and fourth-level detail coefficients are obtained in the same manner. In the process, the sequence obtained by wavelet reconstruction of the fourth-level approximation coefficients is used as the low-frequency residual component corresponding to the energy flow link, which is used to retain the continuous change part of the energy residual value at continuous time positions. The detail sequences obtained by wavelet reconstruction of the first-level detail coefficients, second-level detail coefficients, third-level detail coefficients and fourth-level detail coefficients are synthesized by amplitude to form the high-frequency residual component corresponding to the energy flow link, which is used to retain the rapid fluctuation part of the energy residual value at local time positions. The impeller capture link, main shaft transmission link, gearbox transmission link, generator conversion link and grid-connected output link are all processed according to the above db4 wavelet basis and four-level decomposition method to obtain the low-frequency residual component and high-frequency residual component corresponding to each energy flow link, and the low-frequency residual component and high-frequency residual component are kept in the same time position correspondence with the original energy residual value, so that the residual growth component can be determined based on the low-frequency residual component and the residual mutation component can be determined based on the high-frequency residual component.

[0113] When performing four-level discrete wavelet decomposition on the residual time series corresponding to each energy flow link, each level is processed by low-pass filtering, high-pass filtering, and double downsampling. The first level decomposition takes the original residual time series as input to obtain the first-level approximation coefficients and the first-level detail coefficients; the second level decomposition takes the first-level approximation coefficients as input to obtain the second-level approximation coefficients and the second-level detail coefficients; the third level decomposition takes the second-level approximation coefficients as input to obtain the third-level approximation coefficients and the third-level detail coefficients; the fourth level decomposition takes the third-level approximation coefficients as input to obtain the fourth-level approximation coefficients and the fourth-level detail coefficients. The approximation coefficients at each level are used to retain the relatively smooth low-frequency variation part of the energy residual value, and the detail coefficients at each level are used to retain the high-frequency variation part of the energy residual value with obvious local fluctuations. The detail coefficients at each level are not further decomposed to the next level.

[0114] Amplitude synthesis involves taking the absolute values ​​of the detailed reconstruction sequences obtained by wavelet reconstruction of the first, second, third, and fourth level detailed coefficients at the same time position, and then performing a weighted summation according to preset weights to obtain the residual high-frequency component corresponding to that time position. The preset weights are set to 0.4, 0.3, 0.2, and 0.1, respectively. Taking the absolute value is to preserve the fluctuation intensity of each level detailed reconstruction sequence at the same time position and to avoid positive and negative fluctuations canceling each other out during weighted summation, so that the obtained residual high-frequency component can characterize the local abrupt change amplitude of the energy residual value.

[0115] The low-frequency component of the residual is a sequence of low-frequency residual values ​​at continuous time positions of a certain energy flow link, with one low-frequency component value at each time position; the high-frequency component of the residual is a sequence of high-frequency residual values ​​at continuous time positions of a certain energy flow link, with one high-frequency component value at each time position.

[0116] The residual growth component is determined based on the numerical changes of the low-frequency component of the residual at continuous time positions, and the residual mutation component is determined based on the amplitude changes of the high-frequency component of the residual at continuous time positions.

[0117] In specific implementation, when determining the residual growth component, the low-frequency residual components corresponding to the same energy flow link are read in chronological order. The difference between the low-frequency residual component at the current time position and the low-frequency residual component at the previous time position is calculated to obtain the low-frequency growth amount. The low-frequency growth amounts greater than 0 within the preset continuous time position segment are accumulated to obtain the residual growth component corresponding to the energy flow link. When determining the residual mutation component, the high-frequency residual components corresponding to the same energy flow link are read in chronological order. The high-frequency residual components are used as the high-frequency fluctuation amplitude. The high-frequency fluctuation amplitudes within the same preset continuous time position segment are accumulated to obtain the residual mutation component corresponding to the energy flow link. The preset continuous time position segment is set to 12 consecutive time positions.

[0118] The residual growth component is used to characterize the extent of the continuous increase of energy residual in low-frequency trends, while the residual mutation component is used to characterize the intensity of local mutations in energy residual in high-frequency fluctuations.

[0119] Perform Hilbert transform on the energy residual values ​​corresponding to each energy flow link to obtain the residual envelope value, and determine the residual envelope growth based on the changes in the residual envelope value at continuous time positions;

[0120] In specific implementation, the energy residual values ​​corresponding to the same energy flow link are arranged in chronological order to form a residual time series. A Hilbert transform is performed on the residual time series to obtain an analytical sequence corresponding to the residual time series. The residual envelope value is determined based on the amplitude of the analytical sequence at each time position. The residual envelope value maintains the same time position correspondence with the original energy residual value, with each time position corresponding to one residual envelope value. Subsequently, the residual envelope values ​​corresponding to the same energy flow link are read in chronological order. The difference between the residual envelope value at the current time position and the residual envelope value at the previous time position is calculated. Differences greater than 0 are accumulated within a preset continuous time position segment to obtain the residual envelope growth amount corresponding to that energy flow link. In this embodiment, the preset continuous time position segment is set to 12 consecutive time positions.

[0121] The residual envelope growth is used to characterize the degree of continuous rise of the energy residual envelope within a preset continuous time segment, reflecting the degree of energy loss enhancement in the corresponding energy flow link;

[0122] Performing discrete wavelet transform and Hilbert transform on the energy residual values ​​corresponding to each energy flow link is significant in that it separates the continuously increasing, locally abrupt, and overall envelope uplift components that coexist in the original energy residual values. This avoids the influence of short-term wind fluctuations and measurement disturbances when judging solely based on the original energy residual values. Specifically, the discrete wavelet transform can decompose the energy residual values ​​into low-frequency and high-frequency residual components, and further determine the residual growth and abrupt component, thereby reflecting the degree of continuous increase in the energy residual in the low-frequency trend and the intensity of local abrupt changes in the high-frequency fluctuations, respectively. The Hilbert transform can generate residual envelope values ​​based on the energy residual values ​​and further determine the amount of residual envelope growth, thereby reflecting the degree of continuous uplift of the energy residual envelope within a preset continuous time interval. Through the above processing, the energy loss contribution value corresponding to each energy flow link can not only reflect the magnitude of energy loss, but also the growth characteristics, abrupt changes and overall enhancement characteristics of energy loss. This is conducive to more accurately distinguishing the main energy loss links in the impeller capture link, main shaft transmission link, gearbox transmission link, generator conversion link and grid-connected output link, and improving the reliability of health degradation assessment value and health status early warning results.

[0123] The duration of each energy flow link is determined based on the length of time during which the energy residual value continues to increase at continuous time positions.

[0124] In practice, the energy residual values ​​corresponding to the same energy flow link are read in chronological order, and the energy residual value at the current time position is compared with the energy residual value at the previous time position. When the energy residual value at the current time position is greater than the energy residual value at the previous time position, it is determined that the energy residual value between the adjacent time positions continues to increase. When the energy residual value at the current time position is less than or equal to the energy residual value at the previous time position, it is determined that the continuous increase process ends. The longest time period during which the energy residual value continues to increase is counted within the preset continuous time position segment, and this longest time period is determined as the duration corresponding to the energy flow link.

[0125] In this embodiment, the time interval between adjacent time positions is set to 5 minutes. This time interval is the analysis time interval of the wind turbine energy analysis sequence. The original sampling interval of the sensor is not limited. The preset continuous time position segment is set to 12 continuous time positions, corresponding to a continuous analysis duration of 60 minutes, which is used to determine the growth persistence of the energy residual value during continuous operation.

[0126] Within a preset continuous time segment, the energy residual values ​​corresponding to each energy transfer link are accumulated and summed to obtain the cumulative energy residual value of the whole machine in the segment, and the residual ratio corresponding to each energy transfer link is calculated.

[0127] In specific implementation, within a preset continuous time segment, the energy residual values ​​corresponding to the same energy flow link are accumulated to obtain the segment residual cumulative value corresponding to that energy flow link; the energy residual values ​​corresponding to the impeller capture link, main shaft transmission link, gearbox transmission link, generator conversion link, and grid-connected output link within the same segment are accumulated and summed to obtain the segment whole machine energy residual cumulative value; the segment residual cumulative value corresponding to that energy flow link is divided by the segment whole machine energy residual cumulative value to obtain the residual ratio corresponding to that energy flow link;

[0128] Based on the residual growth component, residual mutation component, residual envelope growth amount, duration, and residual ratio, the energy loss contribution value corresponding to each energy flow link is determined;

[0129] The energy flow path with the largest energy loss contribution is identified as the degradation path corresponding to the target wind turbine.

[0130] The degradation link is the energy flow link with the largest energy loss contribution and the most obvious energy loss among the impeller capture link, main shaft transmission link, gearbox transmission link, generator conversion link and grid-connected output link.

[0131] In this embodiment, the generation of the energy loss contribution value includes:

[0132] Read the residual growth component, residual mutation component, residual envelope growth amount, duration and residual ratio of each energy flow link within the same preset continuous time position segment;

[0133] The residual growth component, residual mutation component, residual envelope growth amount, duration and residual ratio of each energy flow link are normalized according to the maximum value of the same index in each energy flow link.

[0134] Based on the preset contribution weights, the normalized residual growth component, residual mutation component, residual envelope growth amount, duration and residual ratio are weighted and summed to determine the energy loss contribution value corresponding to each energy flow link.

[0135] In practical implementation, the preset contribution weights are set as follows: residual growth component 0.3, residual mutation component 0.2, residual envelope growth amount 0.2, duration 0.15, and residual proportion 0.15. The physical meanings of residual growth component, residual mutation component, residual envelope growth amount, duration, and residual proportion are consistent, all belonging to positive evaluation indicators. That is, the larger the value, the stronger the energy loss contribution of the corresponding energy flow link. Among them, residual growth component is used to characterize the degree of continuous increase of energy residual in low-frequency trend; residual mutation component is used to characterize the intensity of local mutation of energy residual in high-frequency fluctuation; residual envelope growth amount is used to characterize the degree of continuous rise of energy residual envelope in preset continuous time position segment; duration is used to characterize the stable continuity of continuous increase of energy residual value; and residual proportion is used to characterize the relative proportion of the energy flow link in the overall energy residual. Therefore, the above five indicators can all be positively normalized and weighted according to the preset contribution weights to determine the energy loss contribution value corresponding to each energy flow link.

[0136] By determining the energy loss contribution value corresponding to each energy transfer link based on the residual growth component, residual mutation component, residual envelope growth amount, duration, and residual ratio, the degradation characteristics of the target wind turbine in the energy transfer process can be reflected from multiple perspectives. Among them, the residual growth component can reflect the degree of continuous increase of energy residual in low-frequency trends, the residual mutation component can reflect the intensity of local mutation of energy residual in high-frequency fluctuations, the residual envelope growth amount can reflect the degree of continuous rise of energy residual envelope in a preset continuous time position segment, the duration can reflect the stable continuity of continuous increase of energy residual value, and the residual ratio can reflect the relative proportion of the corresponding energy transfer link in the total energy residual of the turbine. By normalizing and weighting the above five evaluation indicators, we can avoid misjudgments caused by judging degradation links based on a single energy residual value. This allows the energy loss contribution value to simultaneously reflect the growth rate, abrupt change intensity, envelope rise, persistence characteristics, and overall machine proportion. This enables us to more accurately distinguish the main energy loss links in the impeller capture link, main shaft transmission link, gearbox transmission link, generator conversion link, and grid-connected output link, thereby improving the reliability of health degradation assessment values ​​and health status early warning results.

[0137] In this embodiment, the early warning output module includes:

[0138] Read the energy residual value and energy loss contribution value of the degraded link within a preset continuous time segment;

[0139] Calculate the overall fitting slope of the energy residual value of the degraded link in the preset continuous time position segment as a function of time position, and determine it as the growth trend of the degraded link in the continuous time position.

[0140] In practice, the energy residual values ​​of the degraded link within a preset continuous time segment are read in chronological order. The sequential number of each time position is used as the independent variable, and the energy residual value at the corresponding time position is used as the dependent variable. A linear fit is performed on the energy residual values ​​within the preset continuous time segment to obtain the overall fitting slope of the energy residual value as a function of time position. This overall fitting slope is determined as the growth trend of the degraded link at the continuous time position. When the overall fitting slope is greater than 0, it indicates that the energy residual value corresponding to the degraded link is generally increasing; when the overall fitting slope is less than 0, it indicates that the energy residual value corresponding to the degraded link is generally decreasing; when the overall fitting slope is equal to 0, it indicates that the energy residual value corresponding to the degraded link remains stable. When generating health degradation assessment values ​​subsequently, growth trends less than 0 are treated as 0.

[0141] The energy residual values ​​corresponding to the degradation link within the preset continuous time location segment are accumulated, and the accumulated energy residual values, energy loss contribution values ​​and growth trends are normalized respectively, and the health degradation assessment value of the target wind turbine is generated.

[0142] In practice, the accumulated energy residual value, energy loss contribution value, and growth trend are normalized to convert them into evaluation quantities in which larger values ​​indicate a higher degree of degradation. When the growth trend is less than 0, it indicates that the energy residual value is not increasing continuously, and the growth trend is normalized to 0. Then, a weighted sum is performed according to preset evaluation weights to generate the health degradation evaluation value of the target wind turbine. The preset evaluation weights are 0.40, 0.35, and 0.25, respectively. The larger the health degradation evaluation value, the higher the degree of health degradation of the target wind turbine.

[0143] The energy loss contribution value is further extracted from the energy residual value, but it mainly reflects the relative energy loss contribution of the degraded link in each energy flow link, focusing on determining whether the degraded link is the main source of overall energy loss. The energy residual value corresponding to the degraded link directly reflects the absolute energy loss between the input and output energy values ​​of that link, focusing on determining the actual loss level of that degraded link. Using the energy residual value, energy loss contribution value, and growth trend together to generate the health degradation assessment value can simultaneously consider the absolute loss level, relative contribution level, and direction of continuous deterioration. This avoids misjudgments that occur when relying solely on the energy loss contribution value, such as a high proportion but small absolute loss, and also avoids ignoring the dominant role of the link in overall energy loss when relying solely on the energy residual value. This improves the accuracy of the health degradation assessment value and the reliability of the health status early warning results.

[0144] The health degradation assessment value is compared with the preset health warning threshold. When the health degradation assessment value is less than the preset health warning threshold, the normal operation result is output.

[0145] In this embodiment, the health degradation assessment value is normalized to the range of 0 to 1, and the preset health warning threshold is set to 0.65. When the health degradation assessment value is less than 0.65, the normal operation result is output.

[0146] When the health degradation assessment value is greater than or equal to the preset health warning threshold, the health status warning result is output.

[0147] The health status early warning result is an early warning judgment information output based on the health degradation assessment value, including the degradation link name, the health degradation assessment value, and the corresponding inspection prompts for the degradation link. The corresponding inspection prompts for the degradation link are maintenance inspection information generated based on the degradation link name, which is used to prompt maintenance personnel to focus on checking the impeller, main shaft, gearbox, generator, or grid-connected output links corresponding to the degradation link.

[0148] refer to Figure 2 :Depend on Figure 2 It can be seen that the energy residual value corresponding to the gearbox transmission link shows a gradual increasing trend during continuous monitoring. In the initial monitoring stage, the energy residual value of the gearbox transmission link was approximately 10.5 kWh. As the monitoring time continued to increase, the energy residual value gradually rose to over 15 kWh. Although there were slight fluctuations at some time points due to changes in wind conditions, adjustments in operating conditions, and measurement disturbances, the overall direction of change remained upward. The average energy residual value in the figure is approximately 12.9 kWh. The energy residual values ​​at several later time points were higher than the average level, indicating a continuously increasing energy loss trend in the gearbox transmission link during energy transmission. This corresponds to the technical solution of this invention that identifies degraded links based on changes in energy residual value.

[0149] Figure 2 The trend of energy residual changes reflects the cumulative change of energy loss in the gearbox drive link over time. Analysis of energy residual values ​​at consecutive time points reveals that the gearbox drive link does not exhibit abnormal fluctuations at a single time point, but rather gradually develops enhanced energy loss characteristics during continuous operation. This provides a data foundation for subsequent calculations of residual growth components, duration, and energy loss contribution. This trend chart verifies that the present invention can utilize the temporal variation of energy residual values ​​to identify enhanced energy loss in different energy flow links. Compared to methods that rely solely on changes in grid-connected output power to determine anomalies, this approach can further pinpoint the specific transmission links where energy loss occurs, improving the reliability of wind turbine health degradation assessment and early warning results.

[0150] Example 1: To verify the feasibility of this invention in practice, it was applied to a target wind turbine with a rated power of 2.5MW in Zone B of a mountain wind farm. The wind conditions in the area where this wind turbine is located fluctuate frequently. During routine monitoring, maintenance personnel found that the grid-connected power of this turbine was occasionally lower than that of adjacent turbines. However, when only viewing the grid-connected power curve, it was impossible to determine whether the problem originated from impeller capture, main shaft transmission, gearbox drive, generator conversion, or the grid-connected output stage. This easily led to the problem of knowing only that the output was decreasing, but finding it difficult to pinpoint the source of energy loss.

[0151] In this scenario, the system continuously acquires wind speed, wind direction, air density, rotor speed, pitch angle, main shaft torque, main shaft speed, gearbox input torque, gearbox output torque, generator output power, and grid-connected power data of the target wind turbine through a data acquisition module. After time alignment, anomaly removal, and missing data completion, the system obtains the wind turbine energy analysis sequence. The time interval between adjacent time positions is set to 5 minutes, and the continuous analysis duration is 72 hours, resulting in a total of 864 time positions. The system further determines the wind energy input value, rotor captured energy value, main shaft transmitted energy value, gearbox transmitted energy value, generator conversion energy value, and grid-connected output energy value, and constructs the rotor capture link, main shaft transmission link, gearbox transmission link, generator conversion link, and grid-connected output link. Calculations show that, within the operating range of 7.6 m / s to 8.4 m / s and air density of 1.17 kg / m³ to 1.21 kg / m³, the target wind turbine has an average wind energy input of 336.8 kWh per 5 minutes, an average rotor captured energy of 146.3 kWh, an average main shaft transmitted energy of 141.5 kWh, an average gearbox transmitted energy of 128.6 kWh, an average generator converted energy of 123.9 kWh, and an average grid-connected output energy of 122.7 kWh.

[0152] After calculating the energy residual values ​​for each energy transfer link, the system found that the average energy residual value for the impeller capture link was 190.5 kWh, for the main shaft transmission link it was 4.8 kWh, for the gearbox drive link it was 12.9 kWh, for the generator conversion link it was 4.7 kWh, and for the grid-connected output link it was 1.2 kWh. These residual values ​​are determined by the input and output energy values ​​between adjacent energy nodes. Based on the cumulative residual values ​​of the five energy transfer links, the overall average energy residual value is 214.1 kWh. The residual ratio corresponding to the gearbox drive link is 12.9 kWh divided by 214.1 kWh, resulting in 0.06.

[0153] The system further performs discrete wavelet transform and Hilbert transform on the energy residual values ​​corresponding to each energy flow link to extract the residual growth component, residual mutation component, and residual envelope growth amount, and calculates the energy loss contribution value by combining the duration and residual ratio. Within a preset continuous time segment of 60 minutes, the normalized value of the residual growth component of the gearbox drive link is 0.92, the normalized value of the residual mutation component is 0.86, the normalized value of the residual envelope growth amount is 0.89, the normalized value of the duration is 0.75, and the normalized value of the residual ratio is 0.31. Weighted summation is performed according to preset contribution weights of 0.30 for the residual growth component, 0.20 for the residual mutation component, 0.20 for the residual envelope growth amount, 0.15 for the duration, and 0.15 for the residual ratio, resulting in an energy loss contribution value of 0.79 for the gearbox drive link. Within the same section, the energy loss contributions of the main shaft transmission link, generator conversion link, and grid-connected output link are 0.32, 0.28, and 0.14, respectively. Based on this, the system identifies the gearbox transmission link as a degraded link.

[0154] During the early warning output phase, the system reads the energy residual value, energy loss contribution value, and growth trend of the gearbox drive link, and generates a health degradation assessment value. The health degradation assessment value of this unit gradually increased from 0.41 to 0.72 over 72 consecutive hours, with the time segment exceeding the preset health warning threshold of 0.65 concentrated in the operating segment where the gearbox drive link residual continuously increased. The system outputs a health status warning result, including the name of the degradation link, the health degradation assessment value, and the corresponding inspection prompts, prompting maintenance personnel to focus on inspecting the gearbox drive link. On-site inspection revealed abnormal wear signs in the gearbox lubrication and high-speed transmission components. Compared to methods that rely solely on grid-connected power reduction for judgment, this invention can locate the increased energy loss phenomenon in the gearbox drive link when grid-connected output fluctuations are not yet significant. This narrows the degradation link location from manual inspection of multiple links to a focused inspection of the gearbox drive link, reducing the inspection time from approximately 6 hours to approximately 2 hours. The health status warning result is consistent with the on-site inspection results, proving that this invention can improve the accuracy, location, and maintenance efficiency of wind turbine health degradation identification.

[0155] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A wind turbine health status assessment and early warning system, characterized in that, include: The data acquisition module is used to acquire wind condition monitoring data, rotor operation data, mechanical transmission data, power generation conversion data and grid connection output data of the target wind turbine during operation, perform preprocessing, and obtain the wind turbine energy analysis sequence. The rotor energy determination module is used to determine the wind energy input value and rotor captured energy value of the target wind turbine based on the wind turbine energy analysis sequence. The energy transfer determination module is used to determine the main shaft energy transfer value, gearbox energy transfer value, generator conversion energy value and grid-connected output energy value of the target wind turbine based on the wind turbine energy analysis sequence. The energy flow construction module is used to construct the energy flow link of the target wind turbine based on the wind energy input value, the rotor captured energy value, the main shaft transmitted energy value, the gearbox transmitted energy value, the generator converted energy value, and the grid-connected output energy value. The energy residual determination module is used to determine the energy residual value for each energy flow link; The degradation link determination module is used to perform discrete wavelet transform and Hilbert transform on the energy residual values ​​corresponding to each energy flow link, extract residual growth components, residual mutation components and residual envelope growth amount, and combine duration and residual ratio to determine the energy loss contribution value of each energy flow link, and determine the degradation link corresponding to the target wind turbine. The early warning output module is used to generate a health degradation assessment value for the target wind turbine based on the energy residual value, energy loss contribution value and growth trend corresponding to the degradation link, and output the health status early warning result.

2. The wind turbine health status assessment and early warning system according to claim 1, characterized in that, The wind condition monitoring data is data characterizing the external wind energy input conditions of the target wind turbine, the rotor operation data is data characterizing the process of the target wind turbine rotor capturing wind energy, the mechanical transmission data is data characterizing the transmission of wind energy in the mechanical transmission link after being converted by the rotor, the power generation conversion data is data characterizing the process of mechanical energy being converted into electrical energy by the generator, and the grid connection output data is data characterizing the output of electrical energy from the target wind turbine to the grid.

3. The wind turbine health status assessment and early warning system according to claim 1, characterized in that, The preprocessing includes time alignment, anomaly removal, and missing data completion.

4. The wind turbine health status assessment and early warning system according to claim 1, characterized in that, The impeller energy determination module includes: Read the wind condition monitoring data and rotor operation data corresponding to each time position from the wind turbine energy analysis sequence; Based on wind condition monitoring data and the swept area of ​​the target wind turbine, the wind energy input value of the target wind turbine at each time location is determined; Determine the rotor capture coefficient of the target wind turbine at each time position based on rotor operating data; Based on the wind energy input value and the rotor capture coefficient, the rotor capture energy value of the target wind turbine at each time position is determined.

5. The wind turbine health status assessment and early warning system according to claim 1, characterized in that, The energy transfer determination module includes: Mechanical transmission data, power generation conversion data, and grid-connected output data at each time point are read from the wind turbine energy analysis sequence. Based on the mechanical transmission data and the time interval between adjacent time positions, determine the main shaft transmission energy value and gearbox transmission energy value of the target wind turbine at each time position; Based on the generator output power data in the power generation conversion data and the time interval between adjacent time positions, determine the generator conversion energy value of the target wind turbine at each time position; Based on the grid-connected power data in the grid-connected output data and the time interval between adjacent time locations, the grid-connected output energy value of the target wind turbine at each time location is determined.

6. The wind turbine health status assessment and early warning system according to claim 1, characterized in that, The energy flow construction module includes: According to each time position, the wind energy input value is determined as the input energy value of the rotor capture link, and the rotor capture energy value is determined as the output energy value of the rotor capture link; The impeller capture energy value is determined as the input energy value of the main shaft transmission link, and the main shaft transmission energy value is determined as the output energy value of the main shaft transmission link. The spindle transmits energy as the input energy value of the gearbox drive link, and the gearbox transmits energy as the output energy value of the gearbox drive link. The energy value transmitted by the gearbox is determined as the input energy value of the generator conversion link, and the energy value converted by the generator is determined as the output energy value of the generator conversion link. The generator conversion energy value is determined as the input energy value of the grid-connected output link, and the grid-connected output energy value is determined as the output energy value of the grid-connected output link; Based on the sequential connection relationship of the impeller capture link, main shaft transmission link, gearbox transmission link, generator conversion link and grid-connected output link, construct the energy flow link corresponding to the target wind turbine.

7. The wind turbine health status assessment and early warning system according to claim 1, characterized in that, The energy residual determination module includes: In the energy flow chain, the input energy value and output energy value corresponding to the impeller capture chain, main shaft transmission chain, gearbox transmission chain, generator conversion chain and grid-connected output chain are read according to each time position; For the wind energy input value and the rotor captured energy value of the rotor capture link, determine the corresponding energy residual value of the rotor capture link; For the impeller capture energy value and the main shaft transmission energy value of the main shaft transmission link, determine the corresponding energy residual value of the main shaft transmission link; For the spindle energy value and gearbox energy value of the gearbox transmission link, determine the corresponding energy residual value of the gearbox transmission link; For the gearbox-transmitted energy value and the generator-converted energy value in the generator conversion link, determine the corresponding energy residual value of the generator conversion link; For the generator conversion energy value and grid-connected output energy value of the grid-connected output link, determine the corresponding energy residual value of the grid-connected output link.

8. The wind turbine health status assessment and early warning system according to claim 1, characterized in that, The degradation link determination module includes: The energy residual values ​​corresponding to the impeller capture link, main shaft transmission link, gearbox transmission link, generator conversion link and grid-connected output link are read according to the continuous time position. Perform discrete wavelet transform on the energy residual values ​​corresponding to each energy flow link to decompose them into low-frequency and high-frequency residual components; The discrete wavelet transform uses the db4 wavelet from the Daubechies wavelet family as the preset wavelet basis, and the preset decomposition level is set to four levels. The residual growth component is determined based on the numerical changes of the low-frequency component of the residual at continuous time positions, and the residual mutation component is determined based on the amplitude changes of the high-frequency component of the residual at continuous time positions. Perform Hilbert transform on the energy residual values ​​corresponding to each energy flow link to obtain the residual envelope value, and determine the residual envelope growth based on the changes in the residual envelope value at continuous time positions; The duration of each energy flow link is determined based on the length of time during which the energy residual value continues to increase at continuous time positions. The energy residual values ​​corresponding to each energy transfer link are summed to obtain the cumulative energy residual value of the whole machine in the section, and the residual ratio corresponding to each energy transfer link is calculated. Based on the residual growth component, residual mutation component, residual envelope growth amount, duration, and residual ratio, the energy loss contribution value corresponding to each energy flow link is determined; The energy flow path that contributes the most to energy loss is identified as the degradation path corresponding to the target wind turbine.

9. A wind turbine health status assessment and early warning system according to claim 8, characterized in that, The generation of the energy loss contribution value includes: Read the residual growth component, residual mutation component, residual envelope growth amount, duration and residual ratio corresponding to each energy flow link; The residual growth component, residual mutation component, residual envelope growth amount, duration and residual ratio of each energy flow link are normalized respectively; The energy loss contribution value corresponding to each energy flow link is determined by weighted summation of the normalized residual growth component, residual mutation component, residual envelope growth amount, duration and residual ratio.

10. A wind turbine health status assessment and early warning system according to claim 1, characterized in that, The early warning output module includes: Read the energy residual value and energy loss contribution value of the degraded link; Calculate the overall fitting slope of the energy residual value of the degradation link as a function of time position, and determine it as the growth trend of the degradation link at continuous time positions; The energy residual values ​​of the degradation links are accumulated, and the accumulated energy residual values, energy loss contribution values ​​and growth trends are normalized respectively, and the health degradation assessment values ​​of the target wind turbine are generated. The health degradation assessment value is compared with the preset health warning threshold. When the health degradation assessment value is less than the preset health warning threshold, the normal operation result is output. When the health degradation assessment value is greater than or equal to the preset health warning threshold, the health status warning result is output.

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