Method and apparatus for testing no-load noise of motor assembly

Abstract

This invention provides a method and apparatus for testing the no-load noise of a motor assembly. It tests the radial natural frequency of the motors in multiple motor assemblies to obtain the range of radial natural frequencies, thereby calculating the resonant speed range. When a preset test speed exists but is not included in the resonant speed range, or when no preset test speed exists, multiple motor assemblies are tested and calculated based on the anechoic chamber, production line testing environment, and standard speed to obtain test compensation values, thereby determining the no-load noise test standard for the motor assembly. By adding motor natural frequency analysis and motor noise testing at different speeds, the resonant frequency band of the motor can be identified in advance. When formulating test standards, by optimizing the motor natural frequency or avoiding the resonant speed range, it is ensured that the test data reflects the noise of the motor during normal operation. This improves the accuracy of motor noise testing, enhances the consistency and success rate of production line testing, guarantees product quality, and improves user experience.

Description

Technical Field

[0001] The present invention relates to the technical field of motor noise detection and control, and particularly to a no-load noise testing method and device for a motor assembly. Background Technique

[0002] Due to its characteristics of simple structure, small volume, high efficiency, etc., permanent magnet synchronous motors are widely used in the automotive electronics industry, especially in the Electric Power Steering (EPS) system. The EPS motor assembly consists of a motor and a driver. Currently, the mainstream EPS motor assemblies usually integrate the motor and the controller together. After the motor is assembled, it must undergo a no-load noise test, and only after passing can it be regarded as a qualified product.

[0003] Currently, the common testing method is to conduct the test in a testing environment composed of a soundproof box, a guide rail, a testing tooling, etc. after the motor assembly is completed. However, in order to adapt to the fast production rhythm, the structural design is usually relatively complex, and the motor will be affected by factors such as tooling during the test. Therefore, usually a certain batch of samples is selected in an anechoic chamber, the noise is tested at a specified speed and distance, and then the compensation value is calculated through the difference between the test data on the production line to eliminate the influence of the tooling, and finally the noise testing standard is determined.

[0004] However, although the existing method can exclude the influence of tooling, it is difficult to eliminate the resonance effect of the motor itself. The natural frequencies of each motor assembly may be different. Therefore, during the test, the motor may resonate with the test speed, resulting in a偏高 test noise value. In addition, the resonance of the motor will increase the vibration on the tooling, resulting in a较大 difference between the test in the anechoic chamber and that on the production line. Using the test noise of the resonant motor as the standard data may also cause misjudgment,进而 affecting the quality assessment of the motor, resulting in qualified motors being misjudged as unqualified, or unqualified motors being misjudged as qualified, affecting the user experience. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a no-load noise testing method and device for a motor assembly to solve the problems of inaccurate quality assessment and test environment differences caused by the resonance of the motor itself on the test results.

[0006] To achieve the above object, embodiments of the present invention provide the following technical solutions:

[0007] The first aspect of the present invention discloses a no-load noise testing method for a motor assembly, and the method includes:

[0008] Testing the radial natural frequencies of the motors in multiple motor assemblies to obtain the ranges of the radial natural frequencies corresponding to the multiple motor assemblies;

[0009] Calculate the resonant rotational speed range based on the range of the radial natural frequency;

[0010] When a preset test speed exists and the resonant speed range includes the preset test speed, the radial natural frequency of the motor in the motor assembly is changed so that the resonant speed range does not include the preset test speed.

[0011] When the preset test speed is not included in the resonant speed range, or when there is no preset test speed, multiple motor assemblies are tested and calculated based on the anechoic chamber, production line test environment and standard speed to obtain test compensation values;

[0012] The no-load noise test standard for the motor assembly is determined based on the test compensation value.

[0013] Preferably, calculating the resonant rotational speed range based on the range of the radial natural frequency includes:

[0014] Obtain the number of pole pairs and slots of multiple motor assemblies;

[0015] The order is determined based on the number of pole pairs and the number of slots;

[0016] Calculate the initial resonant rotational speed range based on the range of the radial natural frequencies and the order;

[0017] Based on anechoic chamber testing, the abnormal noise speed range of multiple motor assemblies at multiple speeds was measured.

[0018] If the abnormal noise speed range matches the initial resonance speed range, then the initial speed range is determined to be the resonance speed range.

[0019] Preferably, the step of testing the abnormal noise speed range of multiple motor assemblies at multiple speeds using an anechoic chamber includes:

[0020] The noise decibel values ​​of multiple motor assemblies at multiple speeds were tested using an anechoic chamber.

[0021] Plot the speed / noise curve based on the noise decibel value, extract the speed range corresponding to the abnormal noise segment in the curve, and obtain the abnormal noise speed range.

[0022] Preferably, after testing the abnormal noise speed range of multiple motor assemblies at multiple speeds using an anechoic chamber, the method further includes:

[0023] If the abnormal noise speed range does not match the initial resonance speed range, then the abnormal noise speed range is determined to be the resonance speed range.

[0024] Preferably, the testing and calculation of multiple motor assemblies based on the anechoic chamber, production line testing environment, and standard speed to obtain test compensation values ​​includes:

[0025] The first noise decibel value of multiple motor assemblies at standard speed was tested in an anechoic chamber;

[0026] The second noise decibel value of multiple motor assemblies at standard speed was tested in a production line test environment;

[0027] Calculate the difference between the first noise decibel value and the second noise decibel value to obtain multiple differences;

[0028] Calculate the average of multiple differences to obtain the test compensation value.

[0029] A second aspect of this invention discloses a no-load noise testing device for an electric motor assembly, the device comprising:

[0030] The test unit is used to test the radial natural frequency of the motors in multiple motor assemblies, and to obtain the range of radial natural frequencies corresponding to the multiple motor assemblies.

[0031] A range calculation unit is used to calculate the resonant rotational speed range based on the range of the radial natural frequency;

[0032] The modification unit is used to change the radial natural frequency of the motor in the motor assembly when there is a preset test speed and the resonant speed range includes the preset test speed, so that the resonant speed range does not include the preset test speed;

[0033] The compensation value calculation unit is used to test and calculate multiple motor assemblies based on the anechoic chamber, production line test environment and standard speed when the resonance speed range does not include the preset test speed, or when there is no preset test speed.

[0034] The determining unit is used to determine the no-load noise test standard of the motor assembly based on the test compensation value.

[0035] Preferably, the range calculation unit includes:

[0036] The acquisition module is used to acquire the number of pole pairs and slots of the multiple motor assemblies;

[0037] An order determination module is used to determine the order based on the number of pole pairs and the number of slots;

[0038] The first calculation module is used to calculate the initial resonant rotational speed range based on the range of the radial natural frequency and the order;

[0039] The first test module is used to test the abnormal noise speed range of multiple motor assemblies at multiple speeds based on an anechoic chamber.

[0040] The first determining module is used to determine the initial speed range as the resonant speed range if the abnormal noise speed range matches the initial resonant speed range.

[0041] Preferably, the test module includes:

[0042] The testing submodule is used to test the noise decibel values ​​of multiple motor assemblies at multiple speeds in an anechoic chamber.

[0043] The extraction submodule is used to plot the speed / noise curve based on the noise decibel value, extract the speed range corresponding to the abnormal noise segment in the curve, and obtain the abnormal noise speed range.

[0044] Preferably, the device further includes:

[0045] The second determining module is used to determine the abnormal noise speed range as the resonance speed range if the abnormal noise speed range does not match the initial resonance speed range.

[0046] Preferably, the compensation value calculation unit includes:

[0047] The second test module is used to test the first noise decibel value of multiple motor assemblies at standard speed in an anechoic chamber;

[0048] The third test module is used to test the second noise decibel value of multiple motor assemblies at standard speed in a production line test environment;

[0049] The second calculation module is used to calculate the difference between the first noise decibel value and the second noise decibel value, and obtain multiple differences;

[0050] The third calculation module is used to calculate the average value among multiple differences to obtain the test compensation value.

[0051] Based on the above embodiments of the present invention, a method and apparatus for testing the no-load noise of a motor assembly are provided. This method tests the radial natural frequencies of motors in multiple motor assemblies to obtain the range of radial natural frequencies. The resonant speed range is calculated based on the range of radial natural frequencies. When a preset test speed exists but is not included in the resonant speed range, or when no preset test speed exists, multiple motor assemblies are tested and calculated based on the anechoic chamber, production line testing environment, and standard speed to obtain test compensation values, thereby determining the no-load noise test standard for the motor assembly. By adding motor natural frequency analysis and motor noise testing at different speeds, the resonant frequency band of the motor can be identified in advance. When formulating test standards, by optimizing the motor natural frequencies or avoiding the resonant speed range, it is ensured that the test data reflects the noise of the motor during normal operation. This improves the accuracy of motor noise testing, enhances the consistency and success rate of production line testing, guarantees product quality, and improves user experience. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0053] Figure 1 A flowchart of a no-load noise testing method for a motor assembly provided in an embodiment of the present invention;

[0054] Figure 2 An example graph showing the rotational speed / noise ratio based on noise decibel values ​​provided in this embodiment of the invention;

[0055] Figure 3 This is a schematic diagram of the anechoic chamber test setup provided in an embodiment of the present invention;

[0056] Figure 4 This is a structural block diagram of a motor assembly no-load noise testing device provided in an embodiment of the present invention. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] In this application, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0059] As the background technology indicates, existing methods have failed to effectively eliminate motor resonance effects, resulting in excessively high test noise and impacting quality assessment. Motor resonance can also cause differences in the testing environment, leading to misjudgments and affecting motor quality and user experience.

[0060] Therefore, this invention provides a method and apparatus for testing the no-load noise of a motor assembly. The method tests the radial natural frequency of the motors in multiple motor assemblies to obtain the range of radial natural frequencies. Based on the range of radial natural frequencies, the resonant speed range is calculated. When a preset test speed exists but is not included in the resonant speed range, or when no preset test speed exists, multiple motor assemblies are tested and calculated based on the anechoic chamber, production line testing environment, and standard speed to obtain test compensation values. The no-load noise test standard for the motor assembly is determined based on the test compensation values. By adding motor natural frequency analysis and motor noise testing at different speeds, the resonant frequency band of the motor can be identified in advance. When formulating test standards, by optimizing the motor's natural frequency or avoiding the resonant speed range, the resonant frequency band is avoided, thus ensuring that the test data reflects the noise of the motor during normal operation. This improves the accuracy of motor noise testing, enhances the consistency and success rate of production line testing, guarantees product quality, and improves user experience.

[0061] See Figure 1 The diagram shows a flowchart of a no-load noise testing method for a motor assembly provided by an embodiment of the present invention.

[0062] It should be noted that this method applies to the operational optimization of EPS (Electric Power Steering) assist motors. This includes:

[0063] Step S101: Test the radial natural frequency of the motors in multiple motor assemblies to obtain the range of radial natural frequencies corresponding to the multiple motor assemblies.

[0064] In the specific implementation step S101, multiple motor assemblies are obtained, which may be from the same optimization batch. The radial natural frequency of the motors in the multiple motor assemblies is tested by hammer impact method to obtain a range of radial natural frequencies.

[0065] Step S102: Calculate the resonant rotational speed range based on the range of radial natural frequencies.

[0066] In the specific implementation of step S102, the range of resonant rotational speeds that may resonate is calculated based on the range of radial natural frequencies.

[0067] Specifically, the calculation process is as follows (processes A1 to A3):

[0068] Process A1: Obtain the number of pole pairs and slots of multiple motor assemblies, and determine the order based on the number of pole pairs and slots; calculate the initial resonant speed range based on the range of radial natural frequencies and the order.

[0069] Taking an 8-pole, 12-slot motor as an example, based on the number of pole pairs (4) and slots (12), the 24th order of the rotational speed is determined to be the order most likely to resonate. The initial resonant speed range that may cause resonance is calculated according to formula (1).

[0070] (1)

[0071] Where H1 is the lower limit of the radial natural frequency range; H2 is the upper limit of the radial natural frequency range; N1 is the lower limit of the initial resonant speed range; and N2 is the upper limit of the initial resonant speed range.

[0072] Process A2: Based on the anechoic chamber test, the abnormal noise speed range of multiple motor assemblies at multiple speeds was tested.

[0073] First, the noise decibel values ​​of multiple motor assemblies at multiple speeds were tested in an anechoic chamber.

[0074] For example, within the range of 1000-2300 RPM, a test point is set every 100 RPM, and the speed is usually selected near the rated speed of the motor.

[0075] Then, based on the noise decibel value, a speed / noise curve is plotted, and the speed range corresponding to the abnormal noise segment in the curve is extracted to obtain the abnormal noise speed range.

[0076] For example Figure 2 As shown in the figure, the broken line is the speed / noise curve, and the range of 1600-2200 rpm is the speed range corresponding to the abnormal noise segment.

[0077] Process A3: If the speed range of the abnormal noise segment matches the initial resonance speed range, then the initial resonance speed range is determined to be the resonance speed range.

[0078] It is understandable that if the abnormal noise speed range does not match the initial resonance speed range, then the abnormal noise speed range is determined to be the resonance speed range.

[0079] Step S103: When there is a preset test speed and the resonant speed range includes the preset test speed, change the radial natural frequency of the motor in the motor assembly so that the resonant speed range does not include the preset test speed.

[0080] In the specific implementation of step S103, it is checked whether a preset test speed exists. If a preset test speed exists, it is determined whether the preset test speed is within the resonant speed range, that is, whether the resonant speed range includes the preset test speed. If a preset test speed exists and the resonant speed range includes the preset test speed, the radial natural frequency of the motor in the motor assembly is changed so that the resonant speed range does not include the preset test speed.

[0081] It should be noted that changing the radial natural frequency of the motor in the motor assembly, for example by optimizing the mass of the motor shaft or the overall structural modes, can alter the radial natural frequency.

[0082] Step S104: When the resonant speed range does not include the preset test speed, or when there is no preset test speed, multiple motor assemblies are tested and calculated based on the anechoic chamber, production line test environment and standard speed to obtain the test compensation value.

[0083] It should be noted that when there is a preset test speed, and the preset test speed is not included in the resonant speed range, the preset test speed is used as the standard speed. Then, based on the anechoic chamber, the production line test environment, and the standard speed, multiple motor assemblies are tested and calculated to obtain the test compensation value.

[0084] Understandably, the absence of a preset test speed means that the no-load test point can be adjusted. Based on this, any speed outside the resonant speed range is defined as the standard speed (e.g., if the speed range is 1600-1800 rpm, the standard speed is set to any speed within the range of less than 1600 rpm or greater than 1800 rpm). Then, based on the anechoic chamber, the production line testing environment, and the standard speed, multiple motor assemblies are tested and calculated to obtain test compensation values.

[0085] Specifically, based on the anechoic chamber, production line testing environment, and standard speed, multiple motor assemblies are tested and calculated to obtain the test compensation values. The implementation process is as follows (processes B1 to B4).

[0086] Procedure B1: Test the first noise decibel value of multiple motor assemblies at standard speeds in an anechoic chamber.

[0087] In the specific implementation process B1, the current multiple motor assemblies are placed horizontally on the sound-absorbing foam in the anechoic chamber, and sensors are placed at a preset distance from the motor surface. The specific placement method is as follows: Figure 3 As shown.

[0088] in, Figure 3 The 1 in the text represents an anechoic chamber; Figure 3 The 2 in the figure represents the power supply terminal; Figure 3 The 3 in the text represents a microphone; Figure 3 The 4 in the text represents the motor assembly; Figure 3 The number 5 in the text represents sound-absorbing sponge.

[0089] The anechoic chamber 1 is equipped with a power terminal 2, a microphone 3, a motor assembly 4, and sound-absorbing foam 5.

[0090] Specifically, the sound-absorbing sponge 5 is a sound-absorbing sponge with a thickness of 30mm or more. The motor assembly 4 is placed horizontally on the upper surface of the sound-absorbing sponge 5; a microphone 3 (i.e., a sensor) is set 100mm above the upper surface of the horizontally placed motor assembly 4; a power terminal 2 is set at one end of the motor assembly 4.

[0091] It is understandable that this applies to multiple motor assemblies a1, a2...a n In an anechoic chamber, the first noise level in decibels at standard speed was measured for each motor assembly, and these values ​​were denoted as x1, x2, ..., x. n .

[0092] Process B2: Test the second noise decibel value of multiple motor assemblies at standard speeds in a production line test environment.

[0093] In the specific implementation process B2, for multiple motor assemblies a1, a2...a n In the production line testing environment, the second noise decibel value of each motor assembly at standard speed was measured, and the values ​​were c1, c2...c n .

[0094] Process B3: Calculate the difference between the first noise decibel value and the second noise decibel value to obtain multiple differences.

[0095] In the specific implementation process B3, the difference between the first noise decibel value and the second noise decibel value is calculated, that is, the difference between the measured data before and after, c1-x1, c2-x2...c n -x n The differences Δ1, Δ2, ..., Δn are obtained.

[0096] Process B4: Calculate the average of multiple differences to obtain the test compensation value.

[0097] In the specific implementation process B4, the average of the multiple differences is calculated to obtain the test compensation value Δave.

[0098] Step S105: Determine the no-load noise test standard for the motor assembly based on the test compensation value.

[0099] In the specific implementation of step S105, the noise decibel value of each motor assembly produced and tested on the production line will be reduced by the test compensation value Δave, and the no-load noise test standard of the motor assembly will be formulated based on the adjusted noise decibel value.

[0100] For example, if the test values ​​are all between 47 and 49 dB, then the no-load noise test standard for the motor assembly can be initially set at 50 to 52 dB.

[0101] In this embodiment of the invention, by adding analysis of the motor's natural frequency and testing motor noise at different speeds, the resonant frequency band of the motor can be identified in advance. When formulating test standards, the motor's natural frequency can be optimized or the resonant speed range can be avoided to prevent entering the resonant frequency band, thereby ensuring that the test data reflects the noise of the motor during normal operation, rather than the abnormal noise during resonance. This will greatly improve the accuracy of EPS motor noise testing, enhance the consistency and success rate of production line testing, and avoid using incorrect test values ​​as the standard base, thereby reducing the risk of setting excessively high standards and reducing the possibility of defective products being released.

[0102] Corresponding to the no-load noise testing method for a motor assembly provided in the above embodiments of the present invention, see also... Figure 4 The diagram shows a structural block diagram of a motor assembly no-load noise testing device provided in an embodiment of the present invention. The device includes: a testing unit 401, a range calculation unit 402, a modification unit 403, a compensation value calculation unit 404, and a determination unit 405.

[0103] Test unit 401 is used to test the radial natural frequency of the motors in multiple motor assemblies, and to obtain the range of radial natural frequencies corresponding to the multiple motor assemblies.

[0104] The range calculation unit 402 is used to calculate the resonant rotational speed range based on the range of radial natural frequencies.

[0105] The modification unit 403 is used to change the radial natural frequency of the motor in the motor assembly when there is a preset test speed and the resonant speed range includes the preset test speed, so that the resonant speed range does not include the preset test speed.

[0106] The compensation value calculation unit 404 is used to test and calculate multiple motor assemblies based on the anechoic chamber, production line test environment and standard speed when the resonance speed range does not include the preset test speed, or when there is no preset test speed.

[0107] The determination unit 405 is used to determine the no-load noise test standard of the motor assembly based on the test compensation value.

[0108] In this embodiment of the invention, by adding analysis of the motor's natural frequency and testing motor noise at different speeds, the resonant frequency band of the motor can be identified in advance. When formulating test standards, the motor's natural frequency can be optimized or the resonant speed range can be avoided to prevent entering the resonant frequency band, thereby ensuring that the test data reflects the noise of the motor during normal operation, rather than the abnormal noise during resonance. This will greatly improve the accuracy of EPS motor noise testing, enhance the consistency and success rate of production line testing, and avoid using incorrect test values ​​as the standard base, thereby reducing the risk of setting excessively high standards and reducing the possibility of defective products being released.

[0109] Combination Figure 4 The device also includes a range calculation unit 402, comprising an acquisition module, an order determination module, a first calculation module, a first test module, and a first determination module.

[0110] The acquisition module is used to obtain the number of pole pairs and slots of multiple motor assemblies.

[0111] The order determination module is used to determine the order based on the number of pole pairs and the number of slots.

[0112] The first calculation module is used to calculate the initial resonant rotational speed range based on the range and order of the radial natural frequency.

[0113] The first test module is used to test the abnormal noise speed range of multiple motor assemblies at multiple speeds based on an anechoic chamber.

[0114] The first determining module is used to determine the initial speed range as the resonant speed range if the abnormal noise speed range matches the initial resonant speed range.

[0115] Combination Figure 4 The content shown is the test module, which includes: a test submodule and an extraction submodule.

[0116] The testing submodule is used to test the noise decibel values ​​of multiple motor assemblies at multiple speeds in an anechoic chamber.

[0117] The extraction submodule is used to plot the speed / noise curve based on the noise decibel value, extract the speed range corresponding to the abnormal noise segment in the curve, and obtain the abnormal noise speed range.

[0118] Combination Figure 4 The device also includes a second determining module, which determines the abnormal noise speed range as the resonant speed range if the abnormal noise speed range does not match the initial resonant speed range.

[0119] Combination Figure 4 The compensation value calculation unit 404 shown includes: a second test module, a third test module, a second calculation module, and a third calculation module.

[0120] The second test module is used to test the first noise decibel value of multiple motor assemblies at standard speeds in an anechoic chamber.

[0121] The third test module is used to test the second noise decibel value of multiple motor assemblies at standard speeds in a production line test environment.

[0122] The second calculation module is used to calculate the difference between the first noise decibel value and the second noise decibel value, and obtain multiple difference values.

[0123] The third calculation module is used to calculate the average value among multiple differences to obtain the test compensation value.

[0124] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and relevant parts can be referred to the descriptions in the method embodiments. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0125] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0126] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of testing for no-load noise of an electric machine assembly, the method comprising: The method includes: The radial natural frequencies of the motors in multiple motor assemblies are tested to obtain the range of radial natural frequencies for the multiple motor assemblies. Calculate the resonant rotational speed range based on the range of the radial natural frequency; When a preset test speed exists and the resonant speed range includes the preset test speed, the radial natural frequency of the motor in the motor assembly is changed so that the resonant speed range does not include the preset test speed. When the preset test speed is not included in the resonant speed range, or when there is no preset test speed, multiple motor assemblies are tested and calculated based on the anechoic chamber, production line test environment and standard speed to obtain test compensation values; The no-load noise test standard for the motor assembly is determined based on the test compensation value. The step of calculating the resonant rotational speed range based on the range of the radial natural frequency includes: Obtain the number of pole pairs and slots of multiple motor assemblies; The order is determined based on the number of pole pairs and the number of slots; Calculate the initial resonant rotational speed range based on the range of the radial natural frequencies and the order; Based on anechoic chamber testing, the abnormal noise speed range of multiple motor assemblies at multiple speeds was measured. If the abnormal noise speed range matches the initial resonance speed range, then the initial resonance speed range is determined to be the resonance speed range. The process of testing and calculating multiple motor assemblies based on an anechoic chamber, production line testing environment, and standard speed to obtain test compensation values ​​includes: The first noise decibel value of multiple motor assemblies at standard speed was tested in an anechoic chamber; The second noise decibel value of multiple motor assemblies at standard speed was tested in a production line test environment; Calculate the difference between the first noise decibel value and the second noise decibel value to obtain multiple differences; Calculate the average of multiple differences to obtain the test compensation value.

2. The method according to claim 1, characterized in that, The abnormal noise speed range of multiple motor assemblies at multiple speeds, tested using an anechoic chamber, includes: The noise decibel values ​​of multiple motor assemblies at multiple speeds were tested using an anechoic chamber. Plot the speed / noise curve based on the noise decibel value, extract the speed range corresponding to the abnormal noise segment in the curve, and obtain the abnormal noise speed range.

3. The method of claim 1, wherein, After testing the abnormal noise speed range of multiple motor assemblies at multiple speeds using an anechoic chamber, the method further includes: If the abnormal noise speed range does not match the initial resonance speed range, then the abnormal noise speed range is determined to be the resonance speed range.

4. A no-load noise testing apparatus for an electric machine assembly, comprising: The device includes: The test unit is used to test the radial natural frequency of the motors in multiple motor assemblies, and to obtain the range of radial natural frequencies corresponding to the multiple motor assemblies. A range calculation unit is used to calculate the resonant rotational speed range based on the range of the radial natural frequency; The modification unit is used to change the radial natural frequency of the motor in the motor assembly when there is a preset test speed and the resonant speed range includes the preset test speed, so that the resonant speed range does not include the preset test speed; The compensation value calculation unit is used to test and calculate multiple motor assemblies based on the anechoic chamber, production line test environment and standard speed when the resonance speed range does not include the preset test speed, or when there is no preset test speed. A determining unit is used to determine the no-load noise test standard of the motor assembly based on the test compensation value; The range calculation unit includes: An acquisition module is used to acquire the number of pole pairs and slots of multiple motor assemblies; An order determination module is used to determine the order based on the number of pole pairs and the number of slots; The first calculation module is used to calculate the initial resonant rotational speed range based on the range of the radial natural frequency and the order; The first test module is used to test the abnormal noise speed range of multiple motor assemblies at multiple speeds based on an anechoic chamber. The first determining module is used to determine the initial resonance speed range as the resonance speed range if the abnormal noise speed range matches the initial resonance speed range. The compensation value calculation unit includes: The second test module is used to test the first noise decibel value of multiple motor assemblies at standard speed in an anechoic chamber; The third test module is used to test the second noise decibel value of multiple motor assemblies at standard speed in a production line test environment; The second calculation module is used to calculate the difference between the first noise decibel value and the second noise decibel value, and obtain multiple differences; The third calculation module is used to calculate the average value among multiple differences to obtain the test compensation value.

5. The apparatus of claim 4, wherein, The test module includes: The testing submodule is used to test the noise decibel values ​​of multiple motor assemblies at multiple speeds based on an anechoic chamber; The extraction submodule is used to plot the speed / noise curve based on the noise decibel value, extract the speed range corresponding to the abnormal noise segment in the curve, and obtain the abnormal noise speed range.

6. The apparatus of claim 4, wherein, The device further includes: The second determining module is used to determine the abnormal noise speed range as the resonance speed range if the abnormal noise speed range does not match the initial resonance speed range.

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