A method and system for determining the sound value of a wind turbine

Abstract

The present invention provides a method and system for determining the sound value of a wind turbine, including: collecting data on the operating state noise and shutdown state background noise of the wind turbine; screening the data on the operating state noise and shutdown state background noise of the wind turbine according to the condition of similar noise environments, and performing sound value analysis on the screened data; evaluating the pitch audibility of the operating state noise and shutdown state background noise of the wind turbine according to the result of the sound value analysis, and correcting the evaluation result to obtain the pitch audibility of the operating state noise of the wind turbine as the sound value. The present invention improves the accuracy of the pitch audibility of the operating state noise of the wind turbine.

Description

Technical Field

[0001] The present invention belongs to the technical field of wind turbine characteristics testing and evaluation, and particularly relates to a method and system for determining the sound value of a wind turbine. Background Art

[0002] As a clean energy source, the environmental benefits of wind power are mainly reflected in not emitting any harmful gases, not consuming water resources, and reducing carbon dioxide emissions. However, if not properly handled, wind power may cause noise pollution. In densely populated areas, the noise generated by wind turbines should be given sufficient attention.

[0003] All developed wind power countries have realized the impact of wind turbine noise radiation on the environment and have successively introduced wind turbine noise radiation standards. The noise radiation of wind turbines has become an important parameter for evaluating the quality of wind turbines. To ensure the consistency of wind turbine noise assessment and the credibility of the results, a series of wind turbine noise detection standards have been promulgated internationally.

[0004] Taking China as an example, in November 2008, the national standard for wind turbine noise testing, GB / T 22516-2008 "Measurement Method for Wind Turbine Noise", was issued, which is equivalent to adopting IEC 61400-11:2002 Wind turbine generator systems—Acoustic noise measurement technique.

[0005] The International Electrotechnical Commission revised the test standard for wind turbine power characteristics in 2006 and changed the standard number to IEC61400-11, ed.2.1:2006. In November 2012, IEC promulgated IEC 61400-11, ed.3.0; 2012. Taking China as an example, in 2015, GB / T 22516-2015 "Measurement Method for Wind Turbine Noise" was issued, which is equivalent to adopting IEC 61400-11, ed.3.0; 2012.

[0006] The final results of noise testing include the apparent sound power level, 1 / 3 octave spectrum, and sound value.

[0007] The determination of the apparent sound power level requires simultaneous measurement of the sound pressure level at a reference position at a fixed distance downwind of the wind turbine, the output power of the wind turbine, the wind speed and direction on a meteorological mast at least 10 m in height, and the wind speed of the nacelle anemometer. The wind speed corresponding to the output power is deduced from the power curve of the wind turbine and converted to the hub height of the wind turbine according to the wind profile. The relationship between the converted wind speed and the operating noise is fitted, and the operating noise at 0.5 times the integer wind speed is obtained. The relationship between the wind speed on the meteorological mast and the background noise is fitted to obtain the background noise corresponding to 0.5 times the integer wind speed. The operating noise is corrected according to the background noise to obtain the sound pressure level at 0.5 times the integer wind speed, and the corresponding apparent sound power level is calculated.

[0008] For the radiated noise of the wind turbine, 1 / 3 octave analysis is adopted. The use of 1 / 3 octave is mainly because of the human ear's perception of sound. Its frequency resolution ability is not a single frequency but a frequency band, and 1 / 3 octave is generally considered to be a frequency band division method that conforms to the characteristics of the human ear. The 1 / 3 octave spectrum is measured synchronously with the total sound pressure level, and the 1 / 3 octave band sound power spectrum is obtained by statistical methods.

[0009] The above sound power level and 1 / 3 octave analysis are both A-weighted sound levels. The A sound level is a single-value evaluation quantity for noise evaluation, which includes the noise of all frequency components and is a comprehensive reflection of all frequency components of the noise. In fact, determining the degree of interference of noise to people is much more complicated than determining the A sound level. For two sounds with the same sound intensity, if one contains pure tones or the sound energy is concentrated in a narrow frequency band, then this sound will be more annoying than the other. The pitch value of the radiated noise of the wind turbine represents the situation where the noise energy is concentrated in a certain frequency band, and is determined by the difference between the pitch level in the critical band close to the pitch and the masking noise level.

[0010] The pitch values appearing in the noise at different wind speeds should be determined based on narrowband analysis, and narrowband spectral analysis is performed on both the background noise and the operating noise.

[0011] The analysis of the pitch should cover the same wind speed range as the measurement of the sound power level. For each wind speed segment, two 1-minute time periods closest to the central value of the wind speed interval should be analyzed, that is, two 1-minute periods of operating noise and two 1-minute periods of background noise are selected.

[0012] The selected 1-minute measurement times of the operating noise and the background noise are respectively divided into 12 10-second time periods, and 12 average energy narrowband spectra can be obtained using a Hanning window.

[0013] The frequency resolution should be limited within the range shown in Table 1.

[0014] Table 1 Frequency Resolution

[0015] Frequency / Hz Less than 2000 2000～5000 Frequency resolution 2Hz - 5Hz 2Hz - 12.5Hz

[0016] Calculations to be performed for operating noise include:

[0017] When determining each integer, the tonal sound pressure level L of the 12 10s average energy spectra pt,j,k (j = 1, 2…12);

[0018] Determine the masking noise sound pressure level L near the tone in the critical band pn,j,k ;

[0019] Determine the tone value VL k , and the difference ΔL between the tonal sound pressure level and the masking noise level tn,j,k .

[0020] The total tone value VL k is determined by the average energy of the ΔL of the 12 average energy narrowband spectra tn,j,k .

[0021] Regardless of the sound power level, 1 / 3 octave spectrum, and tone value, they are all affected by the background noise during the noise test. Among them, the tone value is more complexly affected by the background noise because it is analyzed for the narrowband spectrum and cannot be simply corrected numerically using a formula. This patent mainly provides a method for analyzing the tone value of the operating noise of a wind turbine, which can consider the influence of the tonal audibility in the background noise on the test results.

[0022] The prior art related to the present invention includes:

[0023] 1) Prior art one

[0024] Clause 8.5.5 of GB / T 22516-2008 "Measurement Method for Noise of Wind Turbines" stipulates the method for background noise correction in the tone value analysis of the radiated noise of wind turbines.

[0025] The average energy L of the masking noise spectral lines in the critical band should be corrected using the background noise. In the range of each critical band where the tone value is located, first determine the background noise sound pressure level L pn,avg,j,k , and then perform energy averaging on all 12 10s spectra to obtain L n,avg,j,k . The average energy of the masking noise spectral lines in the critical band after background noise correction is (see formula (8) of GB / T 22516-2008): n,avg,k .

[0026]

[0027] The clause additionally stipulates that in the corresponding critical band, the background noise level should be at least 6 dB lower than the wind turbine noise level. Otherwise, it should be stated that the masking noise is affected by the background noise.

[0028] Prior art one provides a method for background noise correction in the analysis of the sound value of the radiated noise of a wind turbine, which can eliminate the influence of background noise on masking noise and, to a certain extent, avoid the situation where the pitch in noise analysis comes from background noise.

[0029] However, in principle, the method of prior art one corrects broadband background noise. When there are obvious pitch values in the background noise, the method may have deviations, and it is impossible to determine the influence degree of the background noise pitch value on the final result.

[0030] In each wind speed interval, prior art one only selects 2 minutes of test data. During the long-term operation of the wind turbine, the surrounding noise environment may be quite complex, and 2 minutes of data is difficult to truly represent the actual situation of background noise.

[0031] 2) Prior art two

[0032] Clause 9.5.9 of GB / T 22516-2015 "Measurement Method for Noise of Wind Turbines" stipulates that in the analysis of the sound value of the radiated noise of a wind turbine, the influence of background noise should be considered.

[0033] The narrowband spectrum of background noise in each wind speed interval should be measured. If the pitch contained in the background noise significantly affects the audibility analysis, measures should be taken to determine its influence degree and record it.

[0034] The clause specifically points out that broadband background noise correction is not carried out.

[0035] Prior art two takes into account the limitations of the background noise correction method of prior art one and makes improvements, pointing out that the narrowband spectrum of all background noise data in each wind speed interval should be measured, and the pitch value analysis of background noise should be carried out, rather than broadband background noise correction.

[0036] However, prior art two does not clearly define a specific background noise evaluation method, using vague descriptions such as "significantly affects" and "take measures to determine its influence degree", lacking executability. Summary of the Invention

[0037] To overcome the deficiencies of the above prior art, the present invention proposes a method for determining the sound value of a wind turbine, including:

[0038] Collecting data on the noise of the wind turbine in the operating state and the background noise in the shutdown state;

[0039] Screening the data on the noise of the wind turbine in the operating state and the background noise in the shutdown state according to the condition of similar noise environments, and performing sound value analysis on the screened data;

[0040] Evaluate the pitch audibility of the operating state noise and the background noise in the shutdown state of the wind turbine according to the result of the pitch value analysis, and correct the evaluation result to obtain the pitch audibility of the operating state noise of the wind turbine as the pitch value.

[0041] Preferably, the evaluating the pitch audibility of the operating state noise and the background noise in the shutdown state of the wind turbine according to the result of the pitch value analysis, and correcting the evaluation result includes:

[0042] Divide the homologous pitches and average the energy according to the result of the pitch value analysis;

[0043] Evaluate the pitch audibility of the operating state noise and the background noise in the shutdown state of the wind turbine based on the result of the homologous pitches and average energy, and correct the evaluation result.

[0044] Preferably, the result of dividing the homologous pitches and average the energy includes: the number of spectra, the average frequency, and the average energy of the pitch audibility within each homologous pitch in each wind speed range of the operating state noise, and the number of spectra, the average frequency, and the average energy of the pitch audibility within each homologous pitch in each wind speed range of the background noise in the shutdown state.

[0045] Preferably, the evaluating the pitch audibility of the operating state noise and the background noise in the shutdown state of the wind turbine based on the result of the homologous pitches and average energy, and correcting the evaluation result includes:

[0046] Judge whether there are relevant pitches in the operating state noise of the wind turbine according to the result of the homologous pitches and average energy of the operating state noise of the wind turbine. If there are relevant pitches, correct the pitch audibility of the operating state noise of the wind turbine with the background noise in the shutdown state according to the result of the homologous pitches and average energy of the operating state noise and the background noise in the shutdown state of the wind turbine.

[0047] Preferably, the correcting the pitch audibility of the operating state noise of the wind turbine with the background noise in the shutdown state according to the result of the homologous pitches and average energy of the operating state noise and the background noise in the shutdown state of the wind turbine includes:

[0048] Judge whether there are the relevant pitches of the operating state noise in the background noise in the shutdown state according to the pitch audibility of the operating state noise of the wind turbine;

[0049] If there are relevant pitches, correct the homologous pitches of the pitch audibility of the operating state noise of the wind turbine according to the result of the homologous pitches and average energy of the background noise in the shutdown state.

[0050] Preferably, judging whether there is a tone related to the operating state noise in the background noise in the shutdown state according to the audible pitch of the noise in the operating state of the wind turbine generator set includes:

[0051] If there are several homologous tones in the background noise in the shutdown state, and the proportion of the number of spectra of one of the homologous tones is greater than or equal to the preset number of spectra, it is judged that there is a related tone in the background noise in the shutdown state, otherwise it is judged that there is no related tone.

[0052] Preferably, correcting the homologous tones of the audible pitch of the noise in the operating state of the wind turbine generator set according to the results of the homologous tones and energy averaging of the background noise in the shutdown state includes:

[0053] According to the noise in the operating state within the preset wind speed range, obtain the average frequency of the homologous tones of the operating state noise and the number of spectra within the tone, and calculate the bandwidth of the critical band with the homologous tone frequency as the center of the frequency band within the preset wind speed range of the operating state noise;

[0054] And determine the effective background noise correction frequency according to the bandwidth;

[0055] Judge whether the number of the effective background noise correction frequencies is greater than or equal to the preset number;

[0056] If the result is yes, correct the homologous tones and related tones of the audible pitch of the noise in the operating state of the wind turbine generator set according to the analysis result of the background noise in the shutdown state.

[0057] Preferably, correcting the homologous tones and related tones of the audible pitch of the noise in the operating state of the wind turbine generator set according to the analysis result of the background noise in the shutdown state includes:

[0058] According to the noise in the operating state and the background noise in the shutdown state within the preset wind speed range, obtain the homologous tones of the operating state noise and the audible pitch of the homologous tones, and the homologous correction tones of the background noise in the shutdown state and the audible pitch of the homologous tones;

[0059] Subtract the audible pitches of the operating state noise and the background noise in the shutdown state, and judge whether the difference is less than or equal to the preset value;

[0060] If the result is no, finally correct the related tones of the audible pitch of the operating state noise.

[0061] Preferably, finally correcting the related tones of the audible pitch of the operating state noise includes:

[0062] Obtain the number of spectra of the homologous tones of the operating state noise and the number of spectra of the homologous tones of the background noise in the shutdown state;

[0063] Determine whether the difference in the number of spectra between the operating state noise and the shutdown state background noise is less than or equal to the corresponding proportion of the total number of operating state noise test cycles within the preset wind speed range;

[0064] If so, the operating state noise has relevant tones and the operating state noise is corrected according to the shutdown state background noise to obtain a new tone audibility.

[0065] Preferably, the calculation formula for the tone audibility corrected by the background noise is as follows:

[0066]

[0067] In the formula, ΔL avg,a,m,k is the tone audibility of the operating noise of the m-th homologous corrected tone in the original k-th wind speed range, and ΔL avg,c,a,m,k is the tone audibility of the operating noise of the m-th homologous corrected tone in the k-th wind speed range after being corrected by the background noise, and ΔL avg,a,b,n,k is the tone audibility of the operating noise with the homologous corrected tone n in the background noise within the k-th wind speed range.

[0068] Preferably, the screening of the data of the operating state noise and the shutdown state background noise of the wind turbine according to the condition of similar noise environment includes:

[0069] Average the data of the operating state noise and the shutdown state background noise of the wind turbine collected under the conditions of similar noise environment and preset frequency with a preset time as a cycle to obtain database A;

[0070] Based on the data in database A, screen with an integer multiple of the preset wind speed as the center and the preset wind speed as the interval width to obtain database B;

[0071] Calculate the probability distribution of all temperature data within the preset wind speed range, obtain the maximum probability temperature, and then obtain the temperature range by adding and subtracting the preset temperature from the maximum probability temperature, and screen the data in database B according to the temperature range to obtain database C;

[0072] Calculate the probability distribution of all air pressure data within the preset wind speed range, obtain the maximum probability air pressure, and then obtain the air pressure range by adding and subtracting the preset air pressure from the maximum probability air pressure, and screen the data in database C according to the air pressure range to obtain database D;

[0073] Calculate the probability distribution for all wind direction data within the preset wind speed range. After obtaining the maximum probability wind direction, obtain the wind direction range by adding and subtracting the preset wind direction to the maximum probability wind direction. Screen the data in the database D according to the wind direction range to obtain the database E, where the database E includes different wind speed, temperature, pressure, and wind direction data.

[0074] Preferably, the results obtained by performing sound value analysis on the operating state noise of the wind turbine include: the sound value, frequency, audible degree of the tone of the operating state noise, and the total number of test cycles of all operating state noises in the database E within each frequency spectrum of each wind speed range;

[0075] The results obtained by performing sound value analysis on the background noise value of the wind turbine in the shutdown state include: the sound value, frequency, audible degree of the tone of the background noise in the shutdown state, and the total number of test cycles of all background noises in the shutdown state in the database E within each frequency spectrum of each wind speed range.

[0076] Preferably, before screening the data of the operating state noise and the background noise of the shutdown state of the wind turbine according to the conditions of similar noise environments, performing sound value analysis on the screened data, evaluating the audible degree of the tone of the operating state noise and the background noise of the shutdown state according to the results of the sound value analysis, and correcting the evaluation results to obtain the audible degree of the tone of the operating state noise of the wind turbine as the sound value, further includes:

[0077] When there are multiple homologous tones in the operating state noise, analyze each homologous tone in each wind speed range independently.

[0078] Based on the same inventive concept, the present application also provides a sound value determination system for a wind turbine, including: a collection module, a screening and analysis module, and an evaluation and correction module;

[0079] Among them, the collection module is used to collect data of the operating state noise and the background noise of the shutdown state of the wind turbine;

[0080] Among them, the screening and analysis module is used to screen the data of the operating state noise and the background noise of the shutdown state of the wind turbine according to the conditions of similar noise environments, and perform sound value analysis on the screened data;

[0081] Among them, the evaluation and correction module is used to evaluate the audible degree of the tone of the operating state noise and the background noise of the shutdown state of the wind turbine according to the results of the sound value analysis, and correct the evaluation results to obtain the audible degree of the tone of the operating state noise of the wind turbine as the sound value.

[0082] Compared with the closest prior art, the beneficial effects of the present invention are as follows:

[0083] 1. The present invention realizes a method and system for determining the pitch value of a wind turbine, including: collecting data on the operating state noise and shutdown state background noise of the wind turbine; screening the data on the operating state noise and shutdown state background noise of the wind turbine according to the condition of similar noise environments, and performing pitch value analysis on the screened data; evaluating the pitch audibility of the operating state noise and shutdown state background noise of the wind turbine according to the results of the pitch value analysis, and correcting the evaluation results to obtain the pitch audibility of the operating state noise of the wind turbine as the pitch value. The present invention collects data on the operating state noise and shutdown state background noise of the wind turbine to improve the comprehensiveness of the measurement data. In the case where there is an obvious pitch value in the background noise, an evaluation process for the influence of the pitch audibility of the background noise on the analysis of the operating noise pitch value is given. The process is clear and operable, making up for the deficiencies of the existing technology, and evaluating the data and correcting the evaluation results to improve the accuracy of the pitch audibility of the operating state noise of the wind turbine;

[0084] 2. The present invention takes into account the influence of temperature, air pressure, and wind direction on environmental noise. Through repeated screening of the test database, a database of the operating noise and background noise of the wind turbine in a similar noise environment is obtained. The database can represent a consistent actual noise level, making the pitch value analysis process more reasonable and more applicable;

[0085] 3. Based on the analysis results of the pitch value of the background noise itself, the present invention can determine the influence degree of the background noise on the pitch value of the radiated noise of the wind turbine, and give a pitch audibility correction value to quantify the influence of the background noise on the pitch audibility, making the noise test results of the wind turbine more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 It is a schematic flow chart of a method for determining the pitch value of a wind turbine provided by the present invention;

[0087] Figure 2 It is a schematic diagram of the probability distribution of all temperature data in a certain wind speed range provided by the present invention;

[0088] Figure 3 It is a block diagram of the pitch audibility background noise correction process provided by the present invention;

[0089] Figure 4 It is a schematic diagram of the basic framework of a system for determining the pitch value of a wind turbine provided by the present invention;

[0090] Figure 5 It is a schematic diagram of the detailed framework of a system for determining the pitch value of a wind turbine provided by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0091] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further elaborates on the specific implementation manners of the present invention in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0092] Embodiment 1:

[0093] A schematic flowchart of a method for determining the sound value of a wind turbine provided by the present invention is as Figure 1 shown, and includes:

[0094] Step 1: Collect data on the operating state noise and shutdown state background noise of the wind turbine;

[0095] Step 2: Screen the data on the operating state noise and shutdown state background noise of the wind turbine according to the condition of similar noise environments, and perform sound value analysis on the screened data;

[0096] Step 3: Evaluate the pitch audibility of the operating state noise and shutdown state background noise of the wind turbine according to the results of the sound value analysis, and correct the evaluation results to obtain the pitch audibility of the operating state noise of the wind turbine as the sound value.

[0097] Specifically,

[0098] Step 1 includes: Step 1.

[0099] Step 1:

[0100] Use test equipment that complies with the GB / T 22516-2015 standard to collect the noise and related data of the wind turbine in the operating state and shutdown state respectively. The collection parameters include: equivalent continuous sound pressure level, wind speed, air temperature, air pressure, wind direction, power generation, and the sampling frequency is 1 Hz. In addition, an audio file needs to be recorded, and the frequency is not less than 24 kHz.

[0101] During the data collection process, the operating state data and shutdown state data should be collected at intervals, and switched every half hour. Mark the time periods that clearly affect the noise level during the test (such as vehicle passing by, people talking, animals, etc.).

[0102] Step 2 includes: Step 2 to Step 7.

[0103] Step 2:

[0104] Perform a preliminary screening on all the collected data:

[0105] Delete the obvious error values, missing values, abnormal values, and suspicious data in the test data.

[0106] Delete the data corresponding to the time periods that have been marked and clearly affect the noise level.

[0107] Average the filtered data every 10 seconds to obtain Database A.

[0108] Step Three:

[0109] According to the requirements of GB / T 22516-2015 standard, divide the wind speed range of Database A. Take the integer multiple of 0.5m / s wind speed as the center of the interval, and 0.5m / s as the width of the wind speed interval, such as (6.25 - 6.75m / s, 6.75 - 7.25m / s, etc.). Obtain Database B.

[0110] Step Four:

[0111] Considering that the noise environment may change during the long-term noise test, it is necessary to perform data analysis and background noise correction under similar environmental conditions. This step further filters Database B for three parameters: air temperature, air pressure, and wind direction.

[0112] Since the pitch value analysis is based on the wind speed interval, this step filters the data for each wind speed interval separately. The filtering methods are the same, and the calculation processes are independent.

[0113] Analyze the probability distribution of all air temperature data within the wind speed interval k to obtain the maximum probability air temperature T max,k , such as Figure 2 shown. According to the requirements of Equation (1), filter Database B for air temperature to obtain Database C.

[0114] T max,k -2℃ ≤ T B,k ≤ T max,k +2℃ (1)

[0115] Where: T B，k The air temperature data within the wind speed interval k in Database B.

[0116] Analyze the probability distribution of all air pressure data within the wind speed interval k to obtain the maximum probability air pressure B max，k . According to the requirements of Equation (2), filter Database C for air pressure to obtain Database D.

[0117] B max，k -lhPa ≤ B C，k ≤ B max，k +lhPa (2)

[0118] Where: B C，k The air pressure data within the wind speed interval k in Database C.

[0119] Analyze the probability distribution of all wind direction data within the wind speed interval k to obtain the maximum probability wind direction D max，kAccording to the requirements of formula (3), the wind direction is screened from database D to obtain database E.

[0120] D max，k -15° ≤ D D，k ≤ D max，k +15° (3)

[0121] In the formula: D D，k In database D, the wind direction data within the wind speed interval k.

[0122] 2) Analysis of noise sound value

[0123] The sound value analysis is carried out for both the noise during the operation of the wind turbine and the background noise during the shutdown state.

[0124] Step Five:

[0125] The operation noise sound value analysis method is carried out according to the requirements of clause 9.5 of the standard GB / T 22516-2015. The analysis data is based on database E obtained in Step Four, and the following results are obtained:

[0126] ΔL tn，j，k —— The operation noise sound value of the jth spectrum in the kth wind speed interval;

[0127] f j，k —— The frequency where the jth spectrum of the operation noise is located in the kth wind speed interval;

[0128] ΔL a，j，k —— The operation noise tone audibility of the jth spectrum in the kth wind speed interval;

[0129] N 10s，k —— In database E, the total number of operation noise test cycles in the kth wind speed interval.

[0130] Step Six:

[0131] The background noise sound value analysis is carried out independently according to the same method as in Step Five. The analysis data is based on database E obtained in Step Four, and the following results are obtained:

[0132] ΔL tn，b，l，k —— The background noise sound value of the 1st spectrum in the kth wind speed interval;

[0133] f b，l，k —— The frequency where the 1st spectrum of the background noise is located in the kth wind speed interval;

[0134] ΔL a，b，l，k —— The background noise tone audibility of the 1st spectrum in the kth wind speed interval;

[0135] N 10s，b，k—— The number of all background noise test cycles in the k-th wind speed interval in database E.

[0136] Step Seven:

[0137] For the analysis results of the sound values of the operating noise and the background noise, perform homologous tone division and energy averaging respectively according to the description in Clause 9.5 of GB / T 22516-2015.

[0138] Homologous tones are defined as follows: If the distinguishable tones in each spectrum are within the frequency range of ±25% of the critical band center, then these tones can be considered homologous tones. Each homologous tone is processed and recorded as one tone.

[0139] Nf m，k —— The number of spectra in the m-th homologous tone in the k-th wind speed interval of the operating noise;

[0140] Nf b，n，k —— The number of spectra in the n-th homologous tone in the k-th wind speed interval of the background noise;

[0141] f avg，m，k —— The average frequency of the m-th homologous tone in the k-th wind speed interval of the operating noise;

[0142] ΔL avg，a，m，k —— The energy average of the audible tone of the operating noise in the m-th homologous tone in the k-th wind speed interval;

[0143] f avg，b，n，k —— The average frequency of the n-th homologous tone in the k-th wind speed interval of the background noise;

[0144] ΔL avg，a，b，n，k —— The energy average of the audible tone of the background noise in the n-th homologous tone in the k-th wind speed interval.

[0145] Step 3 includes: Step Eight to Step Thirteen.

[0146] Step Eight:

[0147] According to Clause 9.5.8 of GB / T 22516-2015, judge whether there are relevant tones in the operating state noise of the wind turbine. If the judgment result is that there are no relevant tones, there is no need to perform background noise correction. Otherwise, perform background noise analysis and correction according to Steps Nine to Twelve. The analysis in each wind speed interval should be carried out independently.

[0148] That is:

[0149] When the tone audibility should meet the condition:

[0150] ΔL avg，a，m，k ≥ -3.0 dB (4)

[0151] The tonal audibility shall be recorded, except for the following cases:

[0152] ΔL avg，a，m，k ≥ -3.0 dB, and when less than 20% of the spectra in N 10s，k (10 spectra or more) contain distinguishable homologous tones, the value of ΔL avg，a，m，k shall be recorded as "no relevant tones".

[0153] ΔL avg，a，m，k ≥ -3.0 dB, and when more than 20% but less than 6 spectra of N 10s，k contain distinguishable homologous tones, more measurements are required. A total of 30 spectra may need to be measured.

[0154] Step Nine:

[0155] Judge whether there are relevant tones in the background noise of the wind turbine.

[0156] If there are homologous tones in the background noise and the number of its spectra satisfies: Nf b，n，k ≥ 10%·N 10s，b，k , the background noise shall be recorded as "having relevant tones", otherwise recorded as having no relevant tones.

[0157] If the judgment result is that there are no relevant tones, no background noise correction is required, and the result of the tone value analysis is the result obtained in Step Eight; otherwise, background noise correction is carried out according to Steps Ten to Twelve. The analysis within each wind speed range shall be carried out independently.

[0158] 3) Background noise correction for tonal audibility

[0159] The flow chart of the background noise correction for tonal audibility is shown in Figure 3 as follows. The specific steps are described as follows:

[0160] Step Ten:

[0161] Judge whether there are homologous tones of the operating noise in the background noise.

[0162] When there are homologous tones f avg，m，k of the operating noise and the number of spectra within this homologous tone is Nf m，k , calculate the critical band with f avg，m，k as the center frequency of the frequency band and the frequency band width .

[0163] When, within all spectra f b，l，k of the background noise, there are frequencies that satisfy Equation (5), denote it as the effective background noise correction frequency f b，c，l，k

[0164] favg，m，k -0.25·fb m，k ≤f b，l，k ≤f avg，m，k +0.25·fb m，k (5)

[0165] If the number Nf of the effective background noise correction frequencies f b，c，l，k satisfies Equation (6), it is recorded as: there is a homologous correction tone in the background noise; otherwise, it is recorded as there is no homologous correction tone in the background noise. b，c，l，k If the number Nf of the effective background noise correction frequencies f

[0166] Nf b，c，l，k ≥3 (6)

[0167] If there is a homologous correction tone in the background noise, proceed to Step Eleven; if there is no homologous correction tone in the background noise, the correction process ends, and the judgment conclusion is: there is a relevant tone in the operating noise, and the tone audibility is still ΔL avg，a，m，k .

[0168] When there are multiple homologous tones in the operating noise, each homologous tone is analyzed independently, and Step Ten is repeated. The analysis in each wind speed interval should be carried out independently.

[0169] Step Eleven:

[0170] There is a homologous tone m in the operating noise, and its audibility is ΔL avg，a，m，k , and there is a homologous correction tone n in the background noise, and its audibility is ΔL avg，a，b，n，k . If Equation (7) is satisfied, it is recorded as: the background noise tone may affect the operating noise tone, and proceed to Step Twelve; otherwise, proceed to Step Thirteen.

[0171] ΔL avg，a，m，k --ΔL avg，a，b，n，k ≤3dB (7)

[0172] When there are multiple homologous tones in the operating noise, each homologous tone is analyzed independently, and Step Eleven is repeated. The analysis in each wind speed interval should be carried out independently.

[0173] Step Twelve:

[0174] There is a homologous tone m in the operating noise, and the number of its frequency spectra is N fm，k , and the number of all operating noise test cycles in the wind speed interval k is N 10s，k ; there is a homologous correction tone n in the background noise, and the number of its frequency spectra is N fb，n，kIf the condition of Equation (8) is satisfied, record: the background noise tone has an impact on the operating noise tone, and the judgment conclusion is: there is no relevant tone in the operating noise; otherwise, record: the background noise tone has no impact on the operating noise tone, and the judgment conclusion is: there is a relevant tone in the operating noise, and the tone audibility is still ΔL avg，a，m，k The background noise correction is completed.

[0175] Nf m，k -Nf b，n，k ≤20%·N 10s，k (8)

[0176] If there are multiple homologous tones in the operating noise, each homologous tone shall be analyzed independently, and repeat Step Twelve. The analysis within each wind speed range shall be carried out independently.

[0177] Step Thirteen:

[0178] There is a homologous tone m in the operating noise, where the number of spectra is Nf m，k , and the audibility is ΔL avg，a，m，k , and the total number of operating noise test cycles within the wind speed range k is N 10s，k ; there is a homologous correction tone n in the background noise, where the number of spectra is Nf b，n，k , and the audibility is ΔL avg，a，b，n，k . If the condition of Equation (8) is satisfied, record: the background noise tone has an impact on the operating noise tone, and correct the audibility ΔL avg，a，m，k according to Equation (9) to obtain the tone audibility ΔL avg，c，a，m，k after background noise correction; otherwise, record: the background noise tone has no impact on the operating noise tone, and the judgment conclusion is: there is a relevant tone in the operating noise, and the tone audibility is still ΔL avg，a，m，k . The background noise correction is completed.

[0179]

[0180] If there are multiple homologous tones in the operating noise, each homologous tone shall be analyzed independently, and repeat Step Thirteen. The analysis within each wind speed range shall be carried out independently.

[0181] There is the following alternative for Step Ten:

[0182] Judge whether there is a homologous tone of the operating noise in the background noise.

[0183] When there is a homologous tone f in the operating noise avg，m，k , the number of spectra within this homologous tone is Nf m，k , calculate the critical band with f avg，m，k as the center frequency of the frequency band and the frequency band width .

[0184] When there is a homologous tone f in the background noise avg，b，n，k , and the condition of Equation (5) is satisfied, it is recorded as: there is a homologous corrected tone in the background noise; otherwise, it is recorded as there is no homologous corrected tone in the background noise.

[0185] f avg，m，k -0.25·fb m，k ≤f avg，b，n，k ≤f avg，m，k +0.25·fb m，k (5)

[0186] If there is a homologous corrected tone in the background noise, proceed to Step Eleven; if there is no homologous corrected tone in the background noise, the correction process ends, and the judgment conclusion is: there is a relevant tone in the operating noise, and the tone audibility is still ΔL avg，a，m，k .

[0187] When there are multiple homologous tones in the operating noise, each homologous tone is analyzed independently, and Step Ten is repeated. The analysis within each wind speed range should be carried out independently.

[0188] Embodiment 2:

[0189] Based on the same inventive concept, the present invention also provides a tone value determination system for a wind turbine, the basic framework of which is as Figure 4 shown, including: a collection module, a screening and analysis module, and an evaluation and correction module;

[0190] Among them, the collection module is used to collect data on the operating state noise and the shutdown state background noise of the wind turbine;

[0191] Among them, the screening and analysis module is used to screen the data on the operating state noise and the shutdown state background noise of the wind turbine according to the condition of similar noise environments, and perform tone value analysis on the screened data;

[0192] Among them, the evaluation and correction module is used to evaluate the tone audibility of the operating state noise and the shutdown state background noise of the wind turbine according to the results of the tone value analysis, and correct the evaluation results to obtain the tone audibility of the operating state noise of the wind turbine as the tone value.

[0193] The detailed framework of this system is as Figure 5 shown.

[0194] Among them, the evaluation and correction module includes: a division sub-module and a division evaluation and correction sub-module;

[0195] Among them, the division sub-module is used to divide homologous tones and perform energy averaging according to the results of the tone value analysis;

[0196] A division evaluation and correction sub-module is used to evaluate the tonal audibility of the operation state noise and the shutdown state background noise of the wind turbine based on the results of the homologous tone and energy averaging, and correct the evaluation results.

[0197] The division sub-module is specifically used for the number of spectra, average frequency, and tonal audibility energy averaging within each homologous tone in each wind speed interval of the operation state noise, as well as the number of spectra, average frequency, and tonal audibility energy averaging within each homologous tone in each wind speed interval of the shutdown state background noise.

[0198] The division evaluation and correction sub-module includes: a judgment unit for operation noise-related tones;

[0199] Among them, the judgment unit for operation noise-related tones is used to judge whether there are related tones in the operation state noise of the wind turbine according to the results of the homologous tone and energy averaging of the operation state noise of the wind turbine. If there are related tones, the tonal audibility of the operation state noise of the wind turbine is corrected by the shutdown state background noise according to the results of the homologous tone and energy averaging of the operation state noise and the shutdown state background noise of the wind turbine.

[0200] The judgment unit for operation noise-related tones includes: a judgment sub-unit for shutdown state background noise and a homologous correction sub-unit for operation noise;

[0201] Among them, the judgment sub-unit for shutdown state background noise is used to judge whether there are the operation state noise-related tones in the shutdown state background noise according to the tonal audibility of the operation state noise of the wind turbine.

[0202] Among them, the homologous correction sub-unit for operation noise is used to correct the homologous tones of the tonal audibility of the operation state noise of the wind turbine according to the results of the homologous tone and energy averaging of the shutdown state background noise if there are related tones.

[0203] The judgment sub-unit for shutdown state background noise is specifically used to judge that there are related tones in the shutdown state background noise if there are several homologous tones in the shutdown state background noise and the number of spectra of one of the homologous tones is greater than or equal to the proportion of the preset number of spectra, and judge it as no related tones otherwise.

[0204] The homologous correction sub-unit for operation noise is specifically used to obtain the average frequency and the number of spectra within the tone of the homologous tone of the operation state noise according to the operation state noise within the preset wind speed interval, and calculate the bandwidth of the critical band with the homologous tone frequency within the preset wind speed interval of the operation state noise as the center of the frequency band;

[0205] It is also used to determine the effective background noise correction frequency according to the bandwidth;

[0206] It is also used to determine whether the number of the effective background noise correction frequencies is greater than or equal to a preset number;

[0207] When the result is yes, it is also used to correct the homologous tones and related tones of the audible pitch of the operating state noise of the wind turbine according to the analysis result of the background noise in the shutdown state.

[0208] When the result is yes, correcting the homologous tones and related tones of the audible pitch of the operating state noise of the wind turbine according to the analysis result of the background noise in the shutdown state includes: obtaining the homologous tones of the operating state noise and the audible pitch of the homologous tones, and the homologous correction tones of the background noise in the shutdown state and the audible pitch of the homologous tones according to the operating state noise and the background noise in the shutdown state within a preset wind speed range;

[0209] Subtracting the audible pitch of the operating state noise and the background noise in the shutdown state, and determining whether the difference is less than or equal to a preset value;

[0210] When the result is no, finally correct the related tones of the audible pitch of the operating state noise.

[0211] When the result is no, finally correcting the related tones of the audible pitch of the operating state noise includes: obtaining the number of spectral lines of the homologous tones of the operating state noise and the number of spectral lines of the homologous tones of the background noise in the shutdown state;

[0212] Determining whether the difference between the number of spectral lines of the operating state noise and the number of spectral lines of the background noise in the shutdown state is less than or equal to the corresponding ratio of the total number of operating state noise test cycles within a preset wind speed range;

[0213] If yes, there are related tones in the operating state noise, and correct the operating state noise according to the background noise in the shutdown state to obtain a new audible pitch.

[0214] The calculation formula for the audible pitch corrected by the background noise is as follows:

[0215]

[0216] In the formula, ΔL avg，a，m，k is the audible pitch of the operating noise of the original k-th wind speed range and the m-th homologous correction tone, ΔL avg，c，a，m，k is the audible pitch of the operating noise of the k-th wind speed range and the m-th homologous correction tone after being corrected by the background noise, ΔL avg，a，b，n，k is the audible pitch of the operating noise with the homologous correction tone n existing in the background noise within the k-th wind speed range.

[0217] The screening and analysis module is specifically used for:

[0218] Averaging the wind turbine operating state noise and shutdown state background noise data collected under the conditions of similar noise environment and preset frequency in a cycle of preset time to obtain database A;

[0219] It is also used to screen based on the data in database A with an integer multiple of the preset wind speed as the center and the preset wind speed as the interval width to obtain database B;

[0220] It is also used to calculate the probability distribution of all temperature data within the preset wind speed interval, obtain the maximum probability temperature, then add and subtract the preset temperature from the maximum probability temperature to obtain the temperature range, and screen the data in database B according to the temperature range to obtain database C;

[0221] It is also used to calculate the probability distribution of all air pressure data within the preset wind speed interval, obtain the maximum probability air pressure, then add and subtract the preset air pressure from the maximum probability air pressure to obtain the air pressure range, and screen the data in database C according to the air pressure range to obtain database D;

[0222] It is also used to calculate the probability distribution of all wind direction data within the preset wind speed interval, obtain the maximum probability wind direction, then add and subtract the preset wind direction from the maximum probability wind direction to obtain the wind direction range, and screen the data in database D according to the wind direction range to obtain database E, and database E includes different wind speed, temperature, air pressure and wind direction data.

[0223] The results obtained by performing sound value analysis on the wind turbine operating state noise include: the sound value, frequency, audible degree of the operating state noise tone in each frequency spectrum of each wind speed interval of the operating state noise, and the total number of operating state noise test cycles in database E;

[0224] The results obtained by performing sound value analysis on the wind turbine shutdown state background noise include: the sound value, frequency, audible degree of the shutdown state background noise tone in each frequency spectrum of each wind speed interval of the shutdown state background noise, and the total number of shutdown state background noise test cycles in database E.

[0225] The system further includes: an independent analysis module;

[0226] Among them, the independent analysis module is used to independently analyze each homologous tone in each wind speed interval when there are multiple homologous tones in the operating state noise.

[0227] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0228] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for realizing the functions specified in Figure 1 one or more of the flows Figure 1 or blocks.

[0229] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing devices to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device that realizes the functions specified in Figure 1 one or more of the flows Figure 1 or blocks.

[0230] These computer program instructions can also be loaded onto a computer or other programmable data processing devices, such that a series of operation steps are executed on the computer or other programmable devices to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable devices provide steps for realizing the functions specified in Figure 1 one or more of the flows Figure 1 or blocks.

[0231] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application rather than to limit the scope of its protection. Although the present application has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that after reading the present application, various changes, modifications, or equivalent replacements can still be made to the specific implementation manners of the application. However, these changes, modifications, or equivalent replacements are all within the scope of the protection of the pending claims of the application.

Claims

1. A method for determining the sound value of a wind turbine, characterized in that Including: Collecting data on the operating state noise and shutdown state background noise of a wind turbine; Screening the data on the operating state noise and shutdown state background noise of the wind turbine according to the condition of similar noise environments, and performing pitch value analysis on the screened data; Evaluating the pitch audibility of the operating state noise and shutdown state background noise of the wind turbine according to the result of the pitch value analysis, and correcting the evaluation result to obtain the pitch audibility of the operating state noise of the wind turbine as the pitch value; The evaluating the pitch audibility of the operating state noise and shutdown state background noise of the wind turbine according to the result of the pitch value analysis, and correcting the evaluation result includes: Dividing homologous pitches and averaging energies according to the result of the pitch value analysis; Evaluating the pitch audibility of the operating state noise and shutdown state background noise of the wind turbine based on the result of the homologous pitch and energy average, and correcting the evaluation result; The evaluating the pitch audibility of the operating state noise and shutdown state background noise of the wind turbine based on the result of the homologous pitch and energy average, and correcting the evaluation result includes: Judging whether there are relevant pitches in the operating state noise of the wind turbine according to the result of the homologous pitch and energy average of the operating state noise of the wind turbine. If there are relevant pitches, correcting the pitch audibility of the operating state noise of the wind turbine with the shutdown state background noise according to the result of the homologous pitch and energy average of the operating state noise and shutdown state background noise of the wind turbine; The correcting the pitch audibility of the operating state noise of the wind turbine with the shutdown state background noise according to the result of the homologous pitch and energy average of the operating state noise and shutdown state background noise of the wind turbine includes: Judging whether the shutdown state background noise has the relevant pitch of the operating state noise according to the pitch audibility of the operating state noise of the wind turbine; If there are relevant pitches, correcting the homologous pitch of the pitch audibility of the operating state noise of the wind turbine according to the result of the homologous pitch and energy average of the shutdown state background noise; The correcting the homologous pitch of the pitch audibility of the operating state noise of the wind turbine according to the result of the homologous pitch and energy average of the shutdown state background noise includes: Obtaining the average frequency of the homologous pitch of the operating state noise and the number of spectra within the pitch according to the operating state noise within the preset wind speed range, and calculating the bandwidth of the critical band with the homologous pitch frequency of the operating state noise within the preset wind speed range as the center of the frequency band; And determining the effective background noise correction frequency according to the bandwidth; Judging whether the number of the effective background noise correction frequencies is greater than or equal to the preset number; If the result is yes, correcting the homologous pitch and relevant pitch of the pitch audibility of the operating state noise of the wind turbine according to the analysis result of the shutdown state background noise; The correcting the homologous pitch and relevant pitch of the pitch audibility of the operating state noise of the wind turbine according to the analysis result of the shutdown state background noise includes: Obtain the homologous pitch of the operating state noise and the pitch audibility of the homologous pitch, and the homologous corrected pitch of the shutdown state background noise and the pitch audibility of the homologous pitch according to the operating state noise and the shutdown state background noise within a preset wind speed range; Subtract the pitch audibilities of the operating state noise and the shutdown state background noise, and determine whether the difference is less than or equal to a preset value; If the result is otherwise, finally correct the relevant pitch of the pitch audibility of the operating state noise.

2. The method according to claim 1, wherein The results of dividing the homologous pitch and energy averaging include: the number of spectra, the average frequency, and the energy averaging of the pitch audibility within each homologous pitch in each wind speed range of the operating state noise, and the number of spectra, the average frequency, and the energy averaging of the pitch audibility within each homologous pitch in each wind speed range of the shutdown state background noise.

3. The method according to claim 1, wherein The determination of whether there is a relevant pitch of the operating state noise in the shutdown state background noise according to the pitch audibility of the operating state noise of the wind turbine includes: If there are several homologous pitches in the shutdown state background noise, and the number of spectra of one of the homologous pitches is greater than or equal to a proportion of the preset number of spectra, it is determined that there is a relevant pitch in the shutdown state background noise, otherwise it is determined that there is no relevant pitch.

4. The method according to claim 1, characterized in that, The final correction of the relevant pitch of the pitch audibility of the operating state noise includes: Obtain the number of spectra of the homologous pitch of the operating state noise and the number of spectra of the homologous pitch of the shutdown state background noise; Determine whether the difference between the number of spectra of the operating state noise and the shutdown state background noise is less than or equal to a corresponding proportion of the total number of test cycles of all operating state noises within a preset wind speed range; If so, there is a relevant pitch in the operating state noise, and the operating state noise is corrected according to the shutdown state background noise to obtain a new pitch audibility.

5. The method according to claim 4, wherein The calculation formula of the pitch audibility corrected by the background noise is as follows: In the formula, is the pitch audibility of the operating noise of the m-th homologous corrected tone in the original k-th wind speed interval, is the pitch audibility of the operating noise of the m-th homologous corrected tone in the k-th wind speed interval after background noise correction, is the pitch audibility of the operating noise with the homologous corrected tone n in the background noise in the k-th wind speed interval.

6. The method according to claim 1, wherein The screening of the data of the operating state noise and the shutdown state background noise of the wind turbine according to the condition of similar noise environments includes: Average the data of the operating state noise and the shutdown state background noise of the wind turbine collected under the conditions of similar noise environments and a preset frequency in a preset time period as a cycle to obtain database A; Based on the data in database A, screen with an integer multiple of the preset wind speed as the center and the preset wind speed as the interval width to obtain database B; Calculate the probability distribution of all temperature data within a preset wind speed range, obtain the maximum probability temperature, and then add and subtract a preset temperature from the maximum probability temperature to obtain a temperature range, and screen the data in database B according to the temperature range to obtain database C; Calculate the probability distribution of all air pressure data within a preset wind speed range, obtain the maximum probability air pressure, and then add and subtract a preset air pressure from the maximum probability air pressure to obtain an air pressure range, and screen the data in database C according to the air pressure range to obtain database D; Calculate the probability distribution for all wind direction data within a preset wind speed range. After obtaining the maximum probability wind direction, add and subtract the preset wind direction from the maximum probability wind direction to obtain a wind direction range. Screen the data in the database D according to the wind direction range to obtain the database E, where the database E includes different wind speeds, temperatures, pressures, and wind direction data.

7. The method according to claim 6, wherein The results obtained by analyzing the sound values of the operating state noise of the wind turbine include: the sound values, frequencies, audible degrees of the tones of the operating state noise, and the total number of test cycles of all the operating state noise in the database E within each frequency spectrum of each wind speed range; the results obtained by analyzing the sound values of the background noise in the shutdown state of the wind turbine include: the sound values, frequencies, audible degrees of the tones of the background noise in the shutdown state, and the total number of test cycles of all the background noise in the shutdown state in the database E within each frequency spectrum of each wind speed range.

8. The method according to claim 1, characterized in that, Before screening the data of the operating state noise and the background noise in the shutdown state of the wind turbine according to the conditions of similar noise environments, analyzing the sound values of the screened data, evaluating the audible degrees of the tones of the operating state noise and the background noise in the shutdown state according to the results of the sound value analysis, and correcting the evaluation results to obtain the audible degree of the tone of the operating state noise of the wind turbine as the sound value, it further includes: When there are multiple homologous tones in the operating state noise, analyze each homologous tone in each wind speed range independently.

9. A sound value determination system for a wind turbine for implementing the method as claimed in claim 1, characterized in that, It includes: A collection module, a screening and analysis module, and an evaluation and correction module; The collection module is used to collect the data of the operating state noise and the background noise in the shutdown state of the wind turbine; The screening and analysis module is used to screen the data of the operating state noise and the background noise in the shutdown state of the wind turbine according to the conditions of similar noise environments and analyze the sound values of the screened data; The evaluation and correction module is used to evaluate the audible degrees of the tones of the operating state noise and the background noise in the shutdown state according to the results of the sound value analysis and correct the evaluation results to obtain the audible degree of the tone of the operating state noise of the wind turbine as the sound value.

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