Electric drive system offline test method and test system

Abstract

The invention relates to the technical field of rotating machinery testing methods, in particular to an off-line testing method and system for an electric drive system. Comprises: setting a test condition of an electric drive system; sampling the plurality of electric drive systems according to a set working condition; constructing a sample order spectrogram of each electric drive system based on the sampling data; constructing an average order spectrogram based on all the sample order spectrograms; obtaining a difference order spectrogram of each electric drive system based on the sample order spectrogram and the average order spectrogram of each electric drive system; and analyzing the difference order spectrogram of each electric drive system to judge whether the electric drive system has abnormal vibration noise or not. According to the off-line test method for the electric drive assembly, the vibration noise of the electric drive assembly is analyzed through the difference order spectrogram, whether the vibration noise of the electric drive assembly is qualified or not can be accurately judged, the characteristics of the local interval are fully evaluated and analyzed, and the vibration noise evaluation of the whole electric drive assembly is more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of rotating machinery testing methods, and in particular to an off-line testing method and a testing system for an electric drive system. Background Art

[0002] The Electric Drive Assembly is a key component of electric and hybrid vehicles, responsible for converting electrical energy into mechanical energy to drive the vehicle's tires. The Electric Drive Assembly consists of several key components, which can generally be divided into the following main parts:

[0003] 1. Electric motor

[0004] Convert electrical energy into mechanical energy to drive the vehicle; the electric motor can be an AC motor (such as an asynchronous motor, a permanent magnet synchronous motor) or a DC motor;

[0005] 2. Battery Pack

[0006] Store electrical energy and provide it to the motor; the battery pack is usually composed of multiple battery cells, common types include lithium-ion batteries and solid-state batteries;

[0007] 3. Inverter

[0008] The inverter converts direct current (provided by the battery) into alternating current to drive the electric motor; the inverter is also responsible for controlling the speed and torque of the electric motor.

[0009] Because the electric drive assembly involves many rotating parts, such as motors and shaft gear structures, these rotating parts will generate vibration noise during use. Therefore, in order to ensure that the vibration noise of the electric drive assembly can meet the design requirements after it goes offline, the vibration noise test is usually carried out after the electric drive assembly goes offline. The vibration noise test is generally performed using the order analysis method. For example, a prior art entitled a method for evaluating the noise of a reducer proposes a noise evaluation method, which follows the following steps: setting the speed parameters of the reducer to be collected, inputting standard sample data, setting preprocessing parameters, and setting evaluation criteria; obtaining the sound signal, vibration signal, and speed signal of the reducer; storing the obtained sound signal, vibration signal, and speed signal as the data to be tested, and storing the standard sample data; performing equal-angle resampling on the vibration signal, and performing order analysis on the resampled data to obtain order analysis data; performing FFT transformation on the order analysis data to generate the order diagram of the data to be tested, comparing the order diagram parameters of the data to be tested with the order diagram parameters of the standard sample data, and obtaining the evaluation grade according to the evaluation criteria; and displaying the evaluation grade. This method is relatively simple and can evaluate the noise level of the reducer. Because the reducer is actually a rotating component, the order analysis method is suitable for the noise evaluation of rotating components.

[0010] However, this method also has some problems. The main problem is that the order analysis of this method is too simple. Specifically, the method of comparing the order diagram parameters of the data to be tested with the order diagram parameters of the standard sample data and obtaining the evaluation grade according to the evaluation criteria includes: comparing the order according to the order spectrum of the preprocessing parameters and the standard sample data, selecting the order related to the preprocessing parameters for comparison, and obtaining the similarity of each order point; taking the average value of the similarity; obtaining the deviation rate of the standard sample; and obtaining the evaluation grade according to the set evaluation criteria. This evaluation method actually compares the collected data with the standard data, and then determines the noise level. The evaluation test method is relatively broad and imprecise, ignoring the characteristics of the local interval. There may be a defect of insufficient consistency control in specific problems, resulting in the entire noise test being inaccurate and unable to truly reflect the problems of the rotating components. Summary of the invention

[0011] The purpose of this application is to address the deficiencies of the above-mentioned background technology and to provide an off-line test method and a test system for an electric drive system.

[0012] The technical solution of the present application is: a method for testing an electric drive system offline, comprising:

[0013] Set the test conditions of the electric drive system;

[0014] Sampling multiple electric drive systems according to set operating conditions;

[0015] Construct a sample order spectrum of each electric drive system based on the sampled data;

[0016] Construct an average order spectrogram based on all sample order spectrograms;

[0017] A difference order spectrum diagram of each electric drive system is obtained based on the sample order spectrum diagram and the average order spectrum diagram of each electric drive system;

[0018] The difference order spectrum of each electric drive system is analyzed to determine whether the electric drive system has abnormal vibration and noise.

[0019] According to an off-line test method for an electric drive system provided in the present application, the method for setting the test conditions of the electric drive system includes: setting the rotational speed, torque and rate of the rotating components of the electric drive assembly to form multiple conditions.

[0020] According to an off-line test method for an electric drive system provided in the present application, the method for sampling multiple electric drive systems according to set working conditions includes: installing a vibration sensor at a vibration generating position of the electric drive system, collecting vibration noise at the vibration generating position, and determining a sampling rate based on a noise test analysis frequency.

[0021] According to an off-line test method for an electric drive system provided in the present application, the method for constructing a sample order spectrum diagram of each electric drive system based on sampled data includes: constructing a sample order spectrum diagram with the horizontal axis being the speed, the vertical axis being the order, and the color scale being the vibration noise according to the speed, order, and corresponding vibration noise in the sampled data of each electric drive system.

[0022] According to an off-line test method for an electric drive system provided in the present application, the method for constructing an average order spectrum graph based on all sample order spectrum graphs includes: calculating the average value of the vibration noise corresponding to the same speed and the same order in the sample order spectrum graphs of all electric drive systems, and constructing an average order spectrum graph with the horizontal axis being the speed, the vertical axis being the order, and the color scale being the average value of the vibration noise.

[0023] According to an off-line test method for an electric drive system provided in the present application, the method for obtaining a difference order spectrum diagram of each electric drive system includes: calculating the difference between the average value of the vibration noise in the selected sample order spectrum diagram and the vibration noise corresponding to the same speed and the same order in the average order spectrum diagram, and constructing a difference order spectrum diagram with the horizontal axis being the speed, the vertical axis being the order, and the color scale being the difference.

[0024] According to an off-line test method for an electric drive system provided by the present application, the method of analyzing the difference order spectrum diagram of each electric drive system to determine whether the electric drive system has abnormal vibration and noise includes: counting the maximum value of the vibration noise in each speed range of the difference order spectrum diagram, comparing the maximum value of the vibration noise with a set limit value, if the maximum value of the vibration noise is greater than the set limit value, then judging that the vibration noise of the electric drive assembly corresponding to the difference order spectrum diagram is unqualified; if the maximum value of the vibration noise is not greater than the set limit value, then judging that the vibration noise of the electric drive assembly corresponding to the difference order spectrum diagram is qualified.

[0025] The present application also provides an electric drive system offline test system, wherein the test system operates according to any one of the above-mentioned electric drive system offline test methods, including:

[0026] A test condition setting module, the test condition setting module is used to set the test condition of the electric drive system;

[0027] A sampling module, wherein the sampling module samples multiple electric drive systems according to set working conditions;

[0028] A first data processing module, which constructs a sample order spectrum diagram of each electric drive system based on the sampled data;

[0029] A second data processing module, wherein the second data processing module constructs an average order spectrum graph based on all sample order spectrum graphs;

[0030] A third data processing module, wherein the third data processing module obtains a difference order spectrum diagram of each electric drive system based on the sample order spectrum diagram and the average order spectrum diagram of each electric drive system;

[0031] The analysis module is used to analyze the difference order spectrum diagram of each electric drive system to determine whether the electric drive system has abnormal vibration noise.

[0032] According to an electric drive system offline test system provided by the present application, the first data processing module is used to construct a sample order spectrum diagram with the horizontal axis being the speed, the vertical axis being the order, and the color scale being the vibration noise according to the speed, order, and corresponding vibration noise in the sampling data of each electric drive system.

[0033] According to an electric drive system offline test system provided by the present application, the second data processing module is used to calculate the average value of the vibration noise corresponding to the same speed and the same order in the sample order spectrum diagram of all electric drive systems, and construct an average order spectrum diagram with the horizontal axis as the speed, the vertical axis as the order, and the color scale as the average value of the vibration noise.

[0034] According to an electric drive system offline test system provided by the present application, the third data processing module is used to calculate the difference between the average value of the vibration noise corresponding to the same speed and the same order in the selected sample order spectrum diagram and the average order spectrum diagram, and construct a difference order spectrum diagram with the horizontal axis as the speed, the vertical axis as the order, and the color scale as the difference.

[0035] According to an electric drive system offline test system provided by the present application, the analysis module includes:

[0036] A maximum value acquisition module, the maximum value acquisition module is used to count the maximum value of the vibration noise in each speed range of the difference order spectrum diagram;

[0037] A comparison module, the comparison module is used to compare the maximum value of the vibration noise with a set limit value;

[0038] A judgment module, wherein the judgment module judges that the vibration noise of the electric drive assembly corresponding to the difference order spectrum diagram is unqualified when the maximum value of the vibration noise is greater than a set limit, and judges that the vibration noise of the electric drive assembly corresponding to the difference order spectrum diagram is qualified when the maximum value of the vibration noise is not greater than the set limit.

[0039] The advantages of the present application are as follows: 1. Compared with the existing analysis method that only uses the sample order spectrum, the present application further processes the sample order spectrum, and through in-depth analysis of the difference order spectrum, fully evaluates and analyzes the characteristics of the local interval, the vibration and noise evaluation of the entire electric drive assembly is more accurate, the consistency control of the electric drive assembly test is more sufficient, and the entire vibration and noise test method is more accurate, which has great promotion value;

[0040] 2. The method of constructing the test conditions in this application is very simple. By setting the speed, torque and rate of the electric drive assembly test, the corresponding vibration noise can be easily collected to form the required sample order spectrum, which greatly facilitates the subsequent further analysis;

[0041] 3. This application collects vibration noise by installing corresponding vibration sensors. The sampling rate is completely determined based on the noise test analysis frequency. This can form a relatively wide sampling range, which can completely cover the noise test analysis frequency, and facilitate the subsequent analysis and evaluation of vibration noise;

[0042] 4. The method of constructing the sample order spectrum diagram in this application is very simple. The color scale reflects the vibration noise, and the relationship between the speed, order and vibration noise can be obtained more intuitively;

[0043] 5. The average order spectrum constructed in this application is based on multiple sample order spectrums, which can perform overall statistical analysis on multiple electric drive assemblies in the same batch, facilitate subsequent difference judgment of the corresponding electric drive assemblies based on the difference order spectrum, and obtain the difference between each sample and the average value of other samples;

[0044] 6. The method of obtaining the difference order spectrum diagram in the present application is simple, and the difference order spectrum diagram can accurately reflect the difference between the electric drive assembly and the sample data, and the difference is more intuitive, which is convenient for corresponding analysis of the electric drive assembly according to the speed range, and the analysis result is more accurate;

[0045] 7. The judgment method of the test results of the present application is very simple. Based on the obtained difference order spectrum, the maximum value of the vibration noise in each speed analysis interval can be obtained. The maximum value of the vibration noise in each speed analysis interval can be used to construct an analysis curve of the speed and vibration noise. A straight line corresponding to the set limit value is drawn on the analysis curve, and it can be very intuitive and quick to determine whether the vibration noise of the current electric drive assembly is qualified. The overall operation is simple and the analysis is accurate.

[0046] 8. The present application also provides an off-line test system for an electric drive system. The test system of the present application is operated according to the above-mentioned test method to construct a corresponding data processing system to facilitate the automated analysis operation of the off-line test of the electric drive assembly.

[0047] The electric drive assembly off-line test method of the present application analyzes the vibration noise of the electric drive assembly through a difference order spectrum diagram, can accurately determine whether the vibration noise of the electric drive assembly is qualified, fully evaluates and analyzes the characteristics of the local interval, and more accurately evaluates the vibration noise of the entire electric drive assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 : Sample order spectrum of this application;

[0049] Figure 2 : Average order spectrum of this application;

[0050] Figure 3 : The difference order spectrum of this application;

[0051] Figure 4 : Difference order curve diagram of this application. DETAILED DESCRIPTION

[0052] The embodiments of the present application are described in detail below, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0053] In the description of the present application, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0054] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0055] The present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0056] The present application relates to an off-line test method for an electric drive system. The test method of the present application samples and analyzes multiple electric drive assemblies of the same model, constructs a sample order spectrum corresponding to the electric drive assembly based on the sampling data of each electric drive assembly, and then combines all the sample order spectrums to form an average order spectrum of the electric drive assembly. The average order spectrum reflects the vibration and noise conditions of all sampled samples. Each sample is then analyzed separately, and each sample order spectrum is compared with the obtained average order spectrum. The difference between each order spectrum and the average order spectrum is checked to obtain a difference order spectrum. The difference order spectrum can intuitively, accurately and clearly reflect the abnormal situation of the current sample, that is, the current electric drive assembly relative to all sampled samples. Based on this abnormal situation, it can be judged whether the vibration and noise of the sample are qualified, and the off-line test of the electric drive assembly is completed.

[0057] Compared with the prior art, the test method of the present application is to directly construct a sample order spectrum after sampling is completed, and then perform evaluation and analysis based on the difference between the sample order spectrum and the standard order spectrum. This evaluation and analysis method analyzes the electric drive assembly from a large direction and a large range, ignoring the characteristics of the local interval, and there is a problem of insufficient consistency control. The present application uses the sample order spectrum to form an average order spectrum, and then forms a difference order spectrum based on the sample order spectrum and the average order spectrum, and performs analysis and evaluation based on the difference order spectrum. This evaluation and analysis method fully considers the characteristics of the local interval, and the evaluation and analysis of the vibration and noise of the electric drive assembly is more accurate, and the consistency control is sufficient.

[0058] Specifically, an off-line test method of an electric drive system of the present application is performed according to the following steps:

[0059] S1. Setting the test conditions of the electric drive system;

[0060] The purpose of setting the test conditions is to construct a unified test condition. The electric drive assemblies to be tested are tested one by one according to the set test conditions, so that each electric drive assembly, i.e., the sample test conditions, is the same, and the sample data collection is more accurate.

[0061] This application sets the speed, torque and rate of the rotating components of the electric drive assembly to form multiple working conditions; the offline test of the electric drive assembly is mainly to test and evaluate the vibration and noise of the electric drive assembly. The rotating components in the electric drive assembly may generate vibration and noise. Therefore, this application is mainly for sampling and analysis of the rotating components in the electric drive assembly, mainly setting the test conditions according to the speed, torque and rate of the rotating components, and then operating the electric drive assembly according to the set test conditions;

[0062] The specific test conditions are shown in Table 1:

[0063] Table 1: Reference operating conditions

[0064]

[0065] S2. sampling multiple electric drive systems according to set working conditions;

[0066] As mentioned above, the location where the electric drive assembly of the present application generates vibration noise is mainly the rotating component in the electric drive assembly. Therefore, when the electric drive assembly is tested offline, a corresponding vibration sensor is mainly installed on the rotating component of the electric drive assembly to collect the vibration noise at this location using the vibration sensor.

[0067] The sampling of vibration noise of the electric drive system also involves the sampling rate. The sampling rate refers to the sampling frequency. The sampling rate of this application is determined based on the noise test analysis frequency. The sampling rate must be able to completely cover the noise test analysis frequency. The sampling rate of this application is more than twice the noise test analysis frequency. The sampling rate completely covers the noise test analysis frequency to ensure the richness and accuracy of the data and avoid the occurrence of inaccurate tests caused by a small amount of sampled data.

[0068] S3, constructing a sample order spectrum diagram of each electric drive system based on the sampled data;

[0069] By comparing the sampling data and the corresponding working condition data mentioned above, the sample order spectrum diagram represents the corresponding relationship between the sample vibration noise and the corresponding test working condition;

[0070] S4, constructing an average order spectrum based on all sample order spectrums;

[0071] All sample order spectra are counted, and the average order spectra can be obtained by calculation based on all sample order spectra. The average order spectra is the order spectra obtained by averaging the sample order spectra. The average order spectra reflects the average state of all samples.

[0072] S5. Obtaining a difference order spectrum diagram of each electric drive system based on the sample order spectrum diagram and the average order spectrum diagram of each electric drive system;

[0073] The difference order spectrum is an order spectrum formed by the difference between the sample order spectrum and the average order spectrum. The difference order spectrum reflects the difference between each sample and the average order spectrum.

[0074] S6. Analyze the difference order spectrum of each electric drive system to determine whether the electric drive system has abnormal vibration and noise;

[0075] By analyzing the difference order spectrum of each sample, it is possible to determine whether the vibration noise of the sample is abnormal. The judgment method of the present application mainly compares the difference order spectrum with the set limit value, and determines whether there is an abnormality based on the set limit value.

[0076] In some embodiments of the present application, this embodiment optimizes the above step S3. Specifically, Figure 1 As shown, the method of constructing a sample order spectrum diagram of each electric drive system based on the sampling data in this embodiment is: constructing a sample order spectrum diagram with the horizontal axis being the speed, the vertical axis being the order, and the color scale being the vibration noise according to the speed, order, and corresponding vibration noise in the sampling data of each electric drive system.

[0077] like Figure 1 As shown, it is a sample order spectrum diagram of three electric drive systems. The sample order spectrum diagram is a spectrum diagram with the speed as the horizontal axis, the order as the vertical axis, and the vibration noise as the color scale. The speed is determined according to the test conditions, the order is determined according to the sampling rate, and the vibration noise is collected by the vibration sensor.

[0078] In a further embodiment of the present application, the present embodiment optimizes the above step S4. Specifically, Figure 2 The figure shows the average order spectrum diagram described in this embodiment. The method for constructing the average order spectrum diagram based on all sample order spectrum diagrams in this embodiment is: calculating the average value of the vibration noise corresponding to the same speed and the same order in the sample order spectrum diagrams of all electric drive systems, and constructing an average order spectrum diagram with the horizontal axis being the speed, the vertical axis being the order, and the color scale being the average value of the vibration noise.

[0079] In fact, it is to count all the sample order spectra mentioned above, because all the sample order spectra are tested under the same test conditions, and the vibration noise under the same speed and the same order in the sample order spectra is averaged to obtain the average value of all sample order spectra, and then the average spectrum is constructed with the speed as the horizontal axis, the order as the vertical axis, and the average value of the vibration noise as the color scale. The average order spectrum reflects the average state of all samples.

[0080] In a preferred embodiment of the present application, the above step S5 is optimized. Figure 3 As shown, it is the difference order spectrum diagram of this embodiment. The method of obtaining the difference order spectrum diagram of each electric drive system in this embodiment is: calculate the difference between the vibration noise in the selected sample order spectrum diagram and the average value of the vibration noise corresponding to the same speed and the same order in the average order spectrum diagram, and construct a difference order spectrum diagram with the horizontal axis as the speed, the vertical axis as the order, and the color scale as the difference.

[0081] In order to simplify the calculation process, this embodiment optimizes the above method, that is, sets the speed interval. This embodiment divides the above speed into several intervals, and analyzes each speed interval separately. It only needs to calculate the maximum difference between the sample order spectrum and the average order spectrum in each speed interval to construct a simplified difference order spectrum. Figure 4 As shown, it is a difference order curve diagram for optimizing the difference order spectrum diagram. The horizontal axis of the difference order curve diagram is the order, and the vertical axis is the vibration noise. The difference order curve diagram is a curve diagram formed by statistically analyzing the maximum difference in all speed ranges and then connecting the lines.

[0082] The specific calculation formula is as follows:

[0083]

[0084] y i =max(Δ ij )

[0085]

[0086] Where: Δ ij ——The vibration noise value corresponding to order i and speed j on the difference order spectrum;

[0087] Δ i(j-1) ——The vibration noise value corresponding to order i and speed j-1 on the difference order spectrum;

[0088] x ij ——The vibration noise value corresponding to order i and speed j on the sample order spectrum;

[0089] x ij '——Vibration noise value corresponding to order i and speed j on the average order spectrum;

[0090] σ ij ——The standard deviation of the vibration noise value corresponding to order i and speed j on the average order spectrum;

[0091] α——standard deviation coefficient, generally taken as 0.2;

[0092] β——exponential smoothing coefficient;

[0093] T——time constant, generally takes a value of 2;

[0094] y i ——Evaluate the maximum difference between the sample order spectrum and the average order spectrum within the speed range.

[0095] In other embodiments of the present application, this embodiment optimizes the above-mentioned step S6, and the method for analyzing the difference order spectrum diagram of each electric drive system to determine whether the electric drive system has abnormal vibration noise is as follows: statistically calculate the maximum value of the vibration noise in each speed range of the difference order spectrum diagram, and compare the maximum value of the vibration noise with the set limit value; if the maximum value of the vibration noise is greater than the set limit value, then it is judged that the vibration noise of the electric drive assembly corresponding to the difference order spectrum diagram is unqualified; if the maximum value of the vibration noise is not greater than the set limit value, then it is judged that the vibration noise of the electric drive assembly corresponding to the difference order spectrum diagram is qualified.

[0096] In fact, a straight line can be directly drawn on the difference order curve according to the set limit value. For example, the set limit value of this embodiment is 15dB (m / s 2 ), then you can mark the corresponding 15dB(m / s 2 ), as long as there is a part exceeding this straight line in the difference order curve of the sample, it can be judged that the vibration noise of the electric drive system corresponding to the current sample is unqualified. This analysis method is very intuitive and convenient for quick judgment.

[0097] The off-line test method of the electric drive system of the present application is specifically as follows: sampling and analyzing the rotating components in the electric drive assembly, mainly setting the test conditions according to the rotation speed, torque and rate of the rotating components, and then operating the electric drive assembly according to the set test conditions; installing a corresponding vibration sensor on the rotating component of the electric drive assembly, and using the vibration sensor to collect the vibration noise at the position, and the sampling rate is more than twice the noise test analysis frequency; constructing a sample order spectrum with the horizontal axis as the rotation speed, the vertical axis as the order, and the color scale as the vibration noise according to the rotation speed, order and corresponding vibration noise in the sampled data of each electric drive system; calculating the average value of the vibration noise corresponding to the same rotation speed and the same order in the sample order spectrum of all electric drive systems, and constructing an average order spectrum with the horizontal axis as the rotation speed, the vertical axis as the order, and the color scale as the average value of the vibration noise; calculating the difference between the average value of the vibration noise corresponding to the same rotation speed and the same order in the selected sample order spectrum and the average order spectrum, and constructing a difference order spectrum with the horizontal axis as the rotation speed, the vertical axis as the order, and the color scale as the difference; calculating according to the following formula:

[0098]

[0099] y i =max(Δ ij )

[0100]

[0101] Where: Δ ij——The vibration noise value corresponding to order i and speed j on the difference order spectrum;

[0102] Δ i(j-1) ——The vibration noise value corresponding to order i and speed j-1 on the difference order spectrum;

[0103] x ij ——The vibration noise value corresponding to order i and speed j on the sample order spectrum;

[0104] x ij '——Vibration noise value corresponding to order i and speed j on the average order spectrum;

[0105] σ ij ——The standard deviation of the vibration noise value corresponding to order i and speed j on the average order spectrum;

[0106] α——standard deviation coefficient, generally taken as 0.2;

[0107] β——exponential smoothing coefficient;

[0108] T——time constant, generally takes a value of 2;

[0109] y i ——Evaluate the maximum difference between the sample order spectrum and the average order spectrum within the speed range;

[0110] Construct a difference order curve of the difference order spectrum diagram of the corresponding samples, analyze and judge the samples according to the set limit and the difference order curve diagram; count the maximum value of the vibration noise in each speed range of the difference order curve diagram, compare the maximum value of the vibration noise with the set limit value; if the maximum value of the vibration noise is greater than the set limit value, then it is judged that the vibration noise of the electric drive assembly corresponding to the difference order spectrum diagram is unqualified; if the maximum value of the vibration noise is not greater than the set limit value, then it is judged that the vibration noise of the electric drive assembly corresponding to the difference order spectrum diagram is qualified.

[0111] In addition, the present application also provides an electric drive system offline test system, including a test condition setting module, a sampling module, a first data processing module, a second data processing module, a third data processing module and an analysis module, wherein the test condition setting module is used to set the test condition of the electric drive system; the sampling module samples multiple electric drive systems according to the set condition; the first data processing module constructs a sample order spectrum diagram for each electric drive system based on the sampling data; the second data processing module constructs an average order spectrum diagram based on all sample order spectrum diagrams; the third data processing module obtains a difference order spectrum diagram for each electric drive system based on the sample order spectrum diagram and the average order spectrum diagram of each electric drive system; the analysis module is used to analyze the difference order spectrum diagram of each electric drive system to determine whether the electric drive system has vibration noise abnormalities.

[0112] The first data processing module is used to construct a sample order spectrum diagram with the horizontal axis being the speed, the vertical axis being the order, and the color scale being the vibration noise according to the speed, order, and corresponding vibration noise in the sampling data of each electric drive system.

[0113] The second data processing module is used to calculate the average value of the vibration noise corresponding to the same speed and the same order in the sample order spectrum diagram of all electric drive systems, and construct an average order spectrum diagram with the horizontal axis being the speed, the vertical axis being the order, and the color scale being the average value of the vibration noise.

[0114] The third data processing module is used to calculate the difference between the average value of the vibration noise corresponding to the same speed and the same order in the selected sample order spectrum and the average order spectrum, and construct a difference order spectrum with the horizontal axis as the speed, the vertical axis as the order, and the color scale as the difference.

[0115] The analysis module includes a maximum value acquisition module, a comparison module and a judgment module. The maximum value acquisition module is used to count the maximum value of vibration noise in each speed range of the difference order spectrum diagram; the comparison module is used to compare the maximum value of vibration noise with a set limit value; the judgment module makes a judgment that the vibration noise of the electric drive assembly corresponding to the difference order spectrum diagram is unqualified when the maximum value of vibration noise is greater than the set limit value, and makes a judgment that the vibration noise of the electric drive assembly corresponding to the difference order spectrum diagram is qualified when the maximum value of vibration noise is not greater than the set limit value.

[0116] The method of this application is actually applied to test a certain electric drive system.

[0117] The off-line working condition settings of the electric drive system are shown in Table 2:

[0118] Table 2: Offline working conditions of electric drive system

[0119]

[0120] Determine the vibration sensor measurement point of the project and set its sampling rate to 100kHz; set the standard deviation coefficient α to 0.2, the time constant T to 2; set the suspension value to 15;

[0121] A certain electric drive system in this project has 25.75-order noise when the speed is 1000-300rpm in the acceleration condition, which corresponds to the low-speed and high-torque driving condition in the offline condition. By comparing and analyzing the sample order spectrum of this electric drive system with the sample order spectrum of the normal electric drive system, it is confirmed that the order spectrum of the electric drive system in the offline test low-speed and high-torque driving condition is slightly outlier than other samples at 25.75 order, but it is not significant. The limit value of this project near the 25th order in this condition is 130dB (m / s 2), so it cannot be effectively intercepted.

[0122] By comparing the order spectrum of the sample with the average order spectrum of the electric drive system, the difference order spectrum of the sample is obtained. After checking the difference order spectrum, it is found that there is an obvious outlier at the 25.75th order, and its vibration noise exceeds the set limit, so it can be effectively intercepted. Analysis of the difference order curve of the 25.75th order confirms that the main difference is at 1000-3000rpm, and it is reasonably reflected in the difference order spectrum.

[0123] Compared with the comparison sample order spectrum and other sample order spectrum or the average order spectrum, the comparison is not obvious. The difference order spectrum can clearly reflect the difference, and the vibration noise situation can be obtained more accurately, and the interception effect is more precise.

[0124] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present application. The present application may have various changes and improvements without departing from the spirit and scope of the present application, and these changes and improvements fall within the scope of the present application to be protected. The scope of protection claimed in the present application is defined by the attached claims and their equivalents.

Claims

1. An off-line test method for an electric drive system, characterized in that: include, Set the test conditions of the electric drive system; Sampling multiple electric drive systems according to set operating conditions; Construct a sample order spectrum of each electric drive system based on the sampled data; Construct an average order spectrogram based on all sample order spectrograms; A difference order spectrum diagram of each electric drive system is obtained based on the sample order spectrum diagram and the average order spectrum diagram of each electric drive system; The difference order spectrum of each electric drive system is analyzed to determine whether the electric drive system has abnormal vibration and noise.

2. The electric drive system offline testing method according to claim 1, characterized in that: The method for setting the test working condition of the electric drive system includes: setting the rotation speed, torque and speed of the rotating components of the electric drive assembly to form multiple working conditions.

3. The electric drive system offline testing method according to claim 1, characterized in that: The method for sampling multiple electric drive systems according to set working conditions includes: installing a vibration sensor at a vibration generating position of the electric drive system, collecting vibration noise at the vibration generating position, and determining a sampling rate based on a noise test analysis frequency.

4. The electric drive system offline testing method according to claim 1, characterized in that: The method for constructing a sample order spectrum diagram of each electric drive system based on sampled data includes: constructing a sample order spectrum diagram with a horizontal axis of speed, a vertical axis of order, and a color scale of vibration noise according to the speed, order, and corresponding vibration noise in the sampled data of each electric drive system.

5. The electric drive system offline testing method according to claim 1, characterized in that: The method for constructing an average order spectrum graph based on all sample order spectrum graphs includes: calculating the average value of vibration noise corresponding to the same speed and the same order in the sample order spectrum graphs of all electric drive systems, and constructing an average order spectrum graph with the horizontal axis being the speed, the vertical axis being the order, and the color scale being the average value of the vibration noise.

6. The electric drive system offline testing method according to claim 1, characterized in that: The method for obtaining the difference order spectrum diagram of each electric drive system includes: calculating the difference between the average value of the vibration noise corresponding to the same speed and the same order in the selected sample order spectrum diagram and the average order spectrum diagram, and constructing a difference order spectrum diagram with the horizontal axis being the speed, the vertical axis being the order, and the color scale being the difference.

7. The electric drive system offline testing method according to claim 1, characterized in that: The method for analyzing the difference order spectrum diagram of each electric drive system to determine whether the electric drive system has abnormal vibration noise includes: counting the maximum value of the vibration noise in each speed range of the difference order spectrum diagram, comparing the maximum value of the vibration noise with a set limit value, if the maximum value of the vibration noise is greater than the set limit value, then judging that the vibration noise of the electric drive assembly corresponding to the difference order spectrum diagram is unqualified; if the maximum value of the vibration noise is not greater than the set limit value, then judging that the vibration noise of the electric drive assembly corresponding to the difference order spectrum diagram is qualified.

8. An electric drive system offline test system, characterized by: The test system is operated according to any one of the electric drive system offline test methods according to claims 1 to 7, include, A test condition setting module, the test condition setting module is used to set the test condition of the electric drive system; A sampling module, wherein the sampling module samples multiple electric drive systems according to set working conditions; A first data processing module, which constructs a sample order spectrum diagram of each electric drive system based on the sampled data; A second data processing module, wherein the second data processing module constructs an average order spectrum graph based on all sample order spectrum graphs; A third data processing module, wherein the third data processing module obtains a difference order spectrum diagram of each electric drive system based on the sample order spectrum diagram and the average order spectrum diagram of each electric drive system; The analysis module is used to analyze the difference order spectrum diagram of each electric drive system to determine whether the electric drive system has abnormal vibration noise.

9. The electric drive system offline test system according to claim 8, characterized in that: The first data processing module is used to construct a sample order spectrum diagram with the horizontal axis being the speed, the vertical axis being the order, and the color scale being the vibration noise according to the speed, order, and corresponding vibration noise in the sampling data of each electric drive system.

10. The electric drive system offline test system according to claim 8, characterized in that: The second data processing module is used to calculate the average value of the vibration noise corresponding to the same speed and the same order in the sample order spectrum diagram of all electric drive systems, and construct an average order spectrum diagram with the horizontal axis as the speed, the vertical axis as the order, and the color scale as the average value of the vibration noise.

11. The electric drive system offline test system according to claim 8, characterized in that: The third data processing module is used to calculate the difference between the average value of the vibration noise corresponding to the same speed and the same order in the selected sample order spectrum and the average order spectrum, and construct a difference order spectrum with the horizontal axis as the speed, the vertical axis as the order, and the color scale as the difference.

12. The electric drive system offline test system according to claim 8, characterized in that: The analysis module comprises: A maximum value acquisition module, the maximum value acquisition module is used to count the maximum value of the vibration noise in each speed range of the difference order spectrum diagram; A comparison module, the comparison module is used to compare the maximum value of the vibration noise with a set limit value; A judgment module, wherein the judgment module judges that the vibration noise of the electric drive assembly corresponding to the difference order spectrum diagram is unqualified when the maximum value of the vibration noise is greater than a set limit, and judges that the vibration noise of the electric drive assembly corresponding to the difference order spectrum diagram is qualified when the maximum value of the vibration noise is not greater than the set limit.

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