Motor electromagnetic characteristic separation device and method

Abstract

The invention relates to a motor electromagnetic characteristic separation device and method. The device comprises a soundproof box; the test tool is arranged in the soundproof box and is used for installing a motor to be tested; the sound signal processing unit is arranged outside the soundproof box and is used for acquiring noise sound pressure level data; the vibration signal processing unit is arranged outside the soundproof box and is used for acquiring a vibration signal processing result; and the data processing unit is used for carrying out electromagnetic noise characteristic separation according to the noise sound pressure level data, and / or carrying out electromagnetic vibration characteristic separation according to the vibration signal processing result. According to the invention, signal loss caused by excessive leakage of energy in the soundproof box can be avoided, sound pressure data pollution caused by external extra exciting force can be avoided, and meanwhile, after the motor is powered off, the motor can collect enough signal data; when motor electromagnetic noise specially-increased separation is carried out, alignment slicing, data processing, matrix calculation and visual result output of data before and after power failure can be automatically realized.

Description

Technical Field

[0001] The present invention relates to the field of motors, and in particular to a device and method for separating electromagnetic characteristics of a motor. Background Art

[0002] In the prior art, when performing noise testing on a motor, the motor is usually placed in a soundproof structure, and after the motor is driven to rotate, a microphone and a vibration sensor are used to detect noise and vibration signals.

[0003] However, when implementing the above scheme, it is necessary to use a traction motor to drive the motor to be tested to rotate, thereby introducing unnecessary additional exciting force, and the exciting force will generate new characteristic noise, so it is impossible to achieve the characteristic separation of the electromagnetic and mechanical noise of the motor to be tested itself; at the same time, it is necessary to increase the site space to place the traction traction motor test bench, integrated test system, power supply and drive control system, and the traction traction motor needs to leave an interface in the sound insulation structure to connect with the motor to be tested, and energy will leak through the interface, causing sound signal pollution.

[0004] In addition, for precision machinery such as Stirling refrigerators, they use small and micro motors, and most of the motors are split-type and installed in the product as a whole. The motors and other parts will generate noise when running. If only the noise test is performed on the whole machine, it is impossible to locate the noise of each component, and thus it is impossible to accurately identify and separate the mechanical noise and electromagnetic noise of the motor. If the sudden power-off method is used to detect the noise of such small and micro motors, the motor rotor will stop for a short time after the power is off (usually no more than 50ms, and the hollow cup motor is usually less than 10ms, which can be characterized by the electromechanical time constant), resulting in insufficient signal data collection and inaccurate feature recognition. Summary of the invention

[0005] The purpose of the present invention is to provide a motor electromagnetic characteristic separation device and method, which has a simple structure, low implementation cost and small footprint, so as to avoid excessive energy leakage in the sound insulation box, causing signal loss, and eliminate the sound pressure data pollution caused by external additional exciting force. At the same time, by improving the rotational inertia of the rotating shaft, the motor can still run for a certain period of time under the action of inertia after power failure, so as to ensure that the signal acquisition data is sufficient and the resolution is high enough; when performing motor electromagnetic noise characteristic separation, it can automatically realize the alignment slicing, data processing, matrix calculation and visualization result output of the data before and after power failure, so as to provide effective and targeted test and evaluation means for motor fault diagnosis and vibration reduction and noise reduction optimization.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] On the one hand, a motor electromagnetic characteristic separation device is provided, comprising:

[0008] Soundproof box;

[0009] A test fixture, which is arranged inside the soundproof box and is used to install the motor to be tested;

[0010] An acoustic signal processing unit is disposed outside the soundproof box and is used to process the noise signal generated when the motor to be tested is working to obtain noise sound pressure level data;

[0011] A vibration signal processing unit is arranged outside the sound insulation box and is used to process the vibration signal generated when the motor to be tested is working to obtain a vibration signal processing result;

[0012] and a data processing unit connected to the acoustic signal processing unit and / or the vibration signal processing unit, for performing electromagnetic noise feature separation according to the noise sound pressure level data, and / or performing electromagnetic vibration feature separation according to the vibration signal processing result.

[0013] Preferably, the test tool comprises:

[0014] A cylindrical body having an internal accommodation space, a first open end and a second open end;

[0015] A rotating shaft, comprising a rotating shaft body and a first rotating shaft extending end and a second rotating shaft extending end correspondingly connected to two ends of the rotating shaft body, wherein the rotating shaft body is accommodated in the internal accommodation space of the cylindrical body, the first rotating shaft extending end extends toward the first opening end, and the second rotating shaft extending end extends toward the second opening end;

[0016] an end cover connected to the cylindrical body, used to close the second open end, and having an end cover receiving groove for receiving the extended end of the second rotating shaft;

[0017] The rotor of the motor to be tested is connected to the outer peripheral surface of the extended end of the first rotating shaft and extends axially into the first opening end. The stator of the motor to be tested extends axially into the first opening end and is connected to the cylindrical body.

[0018] Preferably, the moment of inertia of the rotating shaft satisfies the following conditions:

[0019] J=(Tmax / 1000)*t / (ω*1000)

[0020] Wherein, J is the moment of inertia; Tmax is the stall torque of the motor to be tested; t is the electromechanical time constant of the motor to be tested; ω is the no-load angular velocity of the motor to be tested.

[0021] Preferably, the test fixture further comprises: a mounting member, which is connected to the cylindrical body and is used to connect the entire test fixture to the frame.

[0022] Preferably, the test fixture further comprises: a bearing mounting member, which is arranged in the internal accommodation space and connected to the inner wall surface of the cylindrical body, and the bearing mounting member is provided with a bearing chamber;

[0023] A first bearing, which is installed in the bearing chamber and sleeved on the outer peripheral surface of the extending end of the first rotating shaft;

[0024] and a second bearing, which is installed in the end cover receiving groove and sleeved on the outer peripheral surface of the extending end of the second rotating shaft.

[0025] Preferably, the test fixture further comprises: a spring, which is sleeved on the outer circumferential surface of the extending end of the first rotating shaft, and whose two ends respectively abut against the first bearing and the shaft shoulder of the extending end of the first rotating shaft.

[0026] Preferably, the inner wall surface and / or outer wall surface of the sound insulation box is connected with sound insulation material.

[0027] On the other hand, a method for separating electromagnetic characteristics of a motor is also provided, which comprises the following steps:

[0028] Assembling the motor to be tested onto the test fixture, and placing the entire frame connected with the test fixture inside the soundproof box;

[0029] The motor control unit controls the stator of the motor to be tested to supply power, and the motor rotor is driven to start rotating through the magnetic field; at the same time, the sound signal acquisition unit and / or the vibration signal acquisition unit are turned on to correspondingly collect noise signals and vibration signals;

[0030] After the speed of the motor to be tested is accelerated from 0 to the maximum speed, the motor to be tested operates at the maximum speed for a predetermined time, and the motor to be tested is powered off until the speed of the motor to be tested is decelerated from the maximum speed to 0, and the sound signal acquisition unit and / or the vibration signal acquisition unit stops signal acquisition when the speed of the motor to be tested is 0;

[0031] Processing the noise signal to obtain noise sound pressure level data, and / or processing the vibration signal to obtain a vibration signal processing result;

[0032] Electromagnetic noise feature separation is performed according to the noise sound pressure level data, and / or electromagnetic vibration feature separation is performed according to the vibration signal processing result.

[0033] Preferably, performing electromagnetic noise feature separation according to the noise sound pressure level data comprises the following steps:

[0034] Importing the noise sound pressure level data, and storing the noise sound pressure level data in a matrix form;

[0035] Separate the acceleration phase sound pressure level data matrix A and the deceleration phase sound pressure level data matrix B from the noise sound pressure level data;

[0036] Data preprocessing is performed on both the acceleration phase sound pressure level data matrix A and the deceleration phase sound pressure level data matrix B, so that the dimensions and directions of the preprocessed acceleration phase sound pressure level data matrix A and the deceleration phase sound pressure level data matrix B are consistent;

[0037] The sound pressure level data in the pre-processed acceleration stage sound pressure level data matrix A and the deceleration stage sound pressure level data matrix B are back-calculated and restored to the acceleration stage sound pressure data matrix A' and the deceleration stage sound pressure data matrix B' respectively;

[0038] Subtract the acceleration phase sound pressure data matrix A' and the deceleration phase sound pressure data matrix B' to obtain a sound pressure difference matrix C;

[0039] The values ​​less than 0 in the sound pressure difference matrix C are assigned a very small positive number, and the sound pressure is converted into a sound pressure level. The sound pressure level data is the electromagnetic noise characteristic of the motor.

[0040] Preferably, performing electromagnetic vibration feature separation according to the vibration signal processing result comprises the following steps:

[0041] Importing vibration signal processing results, and storing the vibration signal processing results in a matrix form;

[0042] Separating the acceleration phase vibration data matrix D and the deceleration phase vibration data matrix E from the vibration signal processing results;

[0043] Performing data preprocessing on both the acceleration phase vibration data matrix D and the deceleration phase vibration data matrix E, so that the dimensions and directions of the preprocessed acceleration phase vibration data matrix D and the deceleration phase vibration data matrix E are consistent;

[0044] Subtracting the acceleration phase vibration data matrix D after data pre-processing and the deceleration phase vibration data matrix E after data pre-processing to obtain a vibration data difference matrix F;

[0045] The values ​​less than 0 in the vibration data difference matrix F are assigned to extremely small positive numbers, and the vibration signal processing result in the vibration data difference matrix F is the electromagnetic vibration characteristic of the motor.

[0046] In summary, the present invention has the following beneficial effects compared with the prior art:

[0047] The motor electromagnetic noise characteristic separation device in the present invention has a simple structure, low implementation cost, small footprint, and a faster and simpler equipment installation and testing process. The motor to be tested, the sound signal acquisition unit, and the vibration signal acquisition unit inside the soundproof box and the external motor control unit, sound signal processing unit, and vibration signal processing unit can all be connected by wired / wireless connection to transmit signals. In the case of wired connection, only a small through hole for the cable to pass through needs to be opened on the soundproof box, and no large hole structure needs to be opened, so as to avoid excessive energy leakage in the soundproof box and cause signal loss.

[0048] At the same time, there is no need to support the motor to be tested through the motor support equipment set outside the box and the large through-holes opened on the soundproof box, thereby preventing the sound pressure data pollution caused by the extra external exciting force; and by improving the rotational inertia of the rotating shaft, the motor can still run for a certain period of time under the action of inertia after the power is cut off, so as to ensure that the signal acquisition data is sufficient and the resolution is high enough;

[0049] When separating the electromagnetic noise characteristics and electromagnetic vibration characteristics of the motor, it can automatically achieve aligned slicing of the data before and after power failure (i.e. separation of the data in the acceleration phase and deceleration phase), data processing, matrix calculation and visualization result output, providing an effective and targeted test and evaluation method for motor fault diagnosis and vibration and noise reduction optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is the overall structural diagram of the motor electromagnetic characteristic separation device in the present invention.

[0051] Figure 2 It is a schematic diagram of the assembly of the frame and the test tooling in the present invention.

[0052] Figure 3 It is a cross-sectional view of the test fixture and the motor to be tested after being assembled in the present invention.

[0053] Figure 4 This is an overall structural diagram of the test fixture and the motor to be tested after being assembled in the present invention.

[0054] Figure 5 It is a flow chart of the steps of the motor electromagnetic characteristic separation method in the present invention.

[0055] Figure 6 It is a flow chart of the steps of obtaining the sound pressure difference matrix in the present invention.

[0056] Figure 7 It is a waterfall diagram of the electromagnetic noise characteristics of the motor generated by the sound pressure level data in the present invention.

[0057] Figure 8 The figure is a flow chart of the steps for obtaining the vibration data difference matrix in the present invention.

[0058] Fig. 9 It is a waterfall diagram of the electromagnetic noise characteristics of the motor generated by the vibration signal processing result in the present invention. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0060] Example 1

[0061] The noise generated by a motor when it is working usually includes electromagnetic noise and mechanical noise. Mechanical noise includes bearing noise, friction noise, wind grinding noise, etc. When a motor in operation is suddenly powered off, the motor phase line can be disconnected instantly, and the motor rotor gradually stops rotating according to the law of inertia until it stops. This process will eliminate all electromagnetic excitation forces and reduce the natural frequency response of the motor stator. Further, by changing the electromagnetic characteristics of the motor before and after power failure, the motor can be targeted for fault location and optimization analysis.

[0062] like Figure 1-2 As shown, this embodiment provides a motor electromagnetic feature separation device, wherein the electromagnetic feature includes an electromagnetic noise feature and an electromagnetic vibration feature. On this basis, the motor electromagnetic feature separation device includes:

[0063] The soundproof box 1 has a soundproof material 110 connected to its inner wall and / or outer wall to prevent external sound signals from entering the soundproof box 1 and affecting the internal motor noise detection;

[0064] A frame 2, which is placed inside the soundproof box 1;

[0065] A test fixture 3, which is connected to the frame 2 and disposed inside the soundproof box 1, and is used to install the motor 100 to be tested;

[0066] A motor control unit 4, which is arranged outside the soundproof box 1 and is connected to the motor 100 to be tested inside the soundproof box 1 by wire or wireless connection, and is used to control the operation of the motor 100 to be tested, and the operation includes one or more of the starting, stopping and speed regulation of the motor 100 to be tested; in this embodiment, the motor control unit 4 is connected to the motor 100 to be tested through a motor cable 41 (for example, a three-phase motor line), one end of the motor cable 41 is connected to the motor control unit 4, and the other end extends into the inside of the soundproof box 1 through a line through hole provided on the soundproof box 1, and is electrically connected to the motor 100 to be tested inside. In addition, the motor control unit 4 and the motor 100 to be tested can also exchange signals through a wireless connection, and the operation of the motor 100 to be tested can also be controlled;

[0067] The acoustic signal collecting unit 5 is arranged inside the soundproof box 1 and is used to collect the noise signal generated when the motor 100 to be tested is working. In this embodiment, the acoustic signal collecting unit 5 includes a microphone or different types of sound pressure sensors, and the distance between the acoustic signal collecting unit 5 and the motor 100 to be tested meets the requirements of relevant standards such as GB / T10069.1-2006 "Determination Method and Limits of Rotating Electrical Machine Noise - Part 1", GB / T 17248.4-1998 "Noise Emitted by Acoustic Machines and Equipment Determined by Sound Power Level, Emitted Sound Pressure Level at Working Position and Other Specified Positions";

[0068] An acoustic signal processing unit 6 is disposed outside the soundproof box 1 and is connected to the acoustic signal collection unit 5 inside the soundproof box 1 by wire or wireless connection, and is used to receive the noise signal and process the noise signal to obtain noise sound pressure level data; in this embodiment, the acoustic signal processing unit 6 is electrically connected to the acoustic signal collection device 5 inside the soundproof box 1 through an acoustic signal transmission cable 61, or the acoustic signal processing unit 6 and the acoustic signal collection device 5 can also exchange signals through a wireless connection, as long as they can complete the acoustic signal transmission;

[0069] A vibration signal acquisition unit 7, which is connected to the test fixture 3 and is used to collect vibration signals generated when the motor 100 to be tested is working. In this embodiment, the vibration signal acquisition unit 7 includes various vibration signal sensors that can realize vibration signal acquisition, and the vibration signal acquisition unit 7 is preferably attached to the axial end face of the test fixture 3;

[0070] A vibration signal processing unit 8 is arranged outside the soundproof box 1 and is connected to the vibration signal acquisition unit 7 inside the soundproof box 1 by wire or wireless connection, and is used to receive the vibration signal and process the vibration signal to obtain a vibration signal processing result, wherein the vibration signal processing result includes one or more of the displacement, displacement velocity and acceleration generated by the vibration; in this embodiment, the vibration signal processing unit 8 is electrically connected to the vibration signal acquisition unit 7 inside the soundproof box 1 through a vibration signal transmission cable 81, or the vibration signal processing unit 8 and the vibration signal acquisition unit 7 can also exchange signals through a wireless connection, as long as they can complete the vibration signal transmission, the vibration signal can be processed;

[0071] And a data processing unit 9, which is connected to the acoustic signal processing unit 6 and / or the vibration signal processing unit 8, and is used to receive noise sound pressure level data and / or vibration signal processing results, and perform electromagnetic noise feature separation according to the noise sound pressure level data, and / or, perform electromagnetic vibration feature separation according to the vibration signal processing results.

[0072] Further, such as Figure 3 As shown, the test tool 3 includes:

[0073] The cylindrical body 31 has an internal accommodation space 311 and has a first opening end 312 and a second opening end 313. In this embodiment, the inner diameter of the first opening end 312 is smaller than the inner diameter of the second opening end 313.

[0074] A rotating shaft, which has a rotating shaft body 323 and a first rotating shaft extension end 321 and a second rotating shaft extension end 322 correspondingly connected to both ends of the rotating shaft body 321, wherein the rotating shaft body 321 is accommodated in the internal accommodation space 311 of the cylindrical body 31, and the first rotating shaft extension end 321 extends toward the first opening end 312 and is located in the internal accommodation space 311, or extends to the outside of the first opening end 312, and similarly, the second rotating shaft extension end 322 extends toward the second opening end 313 and is located in the internal accommodation space 311, or extends to the outside of the second opening end 313; meanwhile, in this embodiment, the rotating shaft body 321, the first rotating shaft extension end 321 and the second rotating shaft extension end 322 can be integrally formed;

[0075] An end cover 33, which is connected to the cylindrical body 31 through an end cover fastener 332, etc., is used to close the second open end 313, and is provided with an end cover receiving groove 331 for receiving the second shaft extension end 322;

[0076] and a mounting member 34 connected to the cylindrical body 31 and used to connect the entire test tool 3 to the frame 2. For example, in this embodiment, the mounting member 34 may be a ring-shaped or hook-shaped structure, and the rope 341 passes through the ring-shaped or hook-shaped mounting member 34 and then connects to the frame 2, thereby realizing the hoisting of the entire test tool 3;

[0077] The rotor 101 of the motor 100 to be tested is connected to the outer circumference of the first shaft extension end 321 and extends into the first opening end 312 along the axial direction. At the same time, the rotor 101 is locked by the rotor locking member 103 so that the rotor 101 and the first shaft extension end 321 can rotate synchronously.

[0078] The stator 102 of the motor to be tested 100 extends into the first open end 312 along the axial direction, and is connected to the cylindrical body 31 in the circumferential direction through stator fasteners 104 such as screws;

[0079] The rotor 101 , the stator 102 , the first open end 312 , the second open end 313 , the shaft body 321 , the first shaft extension end 321 , the second shaft extension end 322 , the cylindrical body 31 , and the end cover 33 are coaxially arranged.

[0080] Further, the moment of inertia of the rotating shaft 32 satisfies the following conditions:

[0081] J=(Tmax / 1000)*t / (ω*1000)

[0082] Wherein, J is the moment of inertia; Tmax is the stall torque of the motor to be tested; t is the electromechanical time constant of the motor to be tested; ω is the no-load angular velocity of the motor to be tested.

[0083] If the sudden power-off method is used to detect and separate the electromagnetic characteristics of small and micro motors, due to the small rotational inertia of small and micro motors, after the motor is powered off, due to the consumption of the tooth torque and system damping, the motor will stop in a very short time (several milliseconds to tens of milliseconds), resulting in the signal acquisition unit being unable to collect enough data; in this embodiment, the rotational inertia of the rotating shaft 32 is improved accordingly, so that after the motor is powered off, the motor can still operate for several seconds to tens of seconds under the action of inertia, so as to ensure that the signal acquisition data is sufficient and the resolution is high enough.

[0084] The working process of the motor electromagnetic characteristic separation device in this embodiment is as follows:

[0085] The rotor 101 and the stator 102 of the motor 100 to be tested are assembled into the first open end 312, and are locked and fixed by the rotor locking member 103 and the stator fastening member 104 respectively;

[0086] The test fixture 3 equipped with the motor 100 to be tested is connected to the frame 2 via the rope 341, and then the frame 2 connected with the test fixture 3 is placed as a whole inside the soundproof box 1;

[0087] Through the control of the motor control unit 4, the motor power supply 10 supplies power to the stator 102 of the motor 100 to be tested, so as to generate an alternating magnetic field, and further drive the rotor 101 to rotate through the magnetic field, so that the motor 100 to be tested is in a working state; at the same time, the sound signal acquisition unit 5 and / or the vibration signal acquisition unit 7 are turned on to correspondingly collect noise signals and / or vibration signals;

[0088] After the motor 100 to be tested has been working for a predetermined time, the motor 100 to be tested is powered off, and after the motor 100 to be tested has completely stopped rotating, the sound signal collection unit 5 and / or the vibration signal collection unit 7 stops collecting signals;

[0089] The acoustic signal processing unit 6 processes the noise signal to obtain noise sound pressure level data, and / or the vibration signal processing unit 8 processes the vibration signal to obtain a vibration signal processing result;

[0090] The data processing unit 9 performs electromagnetic noise feature separation according to the noise sound pressure level data, and / or performs electromagnetic vibration feature separation according to the vibration signal processing result.

[0091] Therefore, the motor electromagnetic characteristic separation device in this embodiment has a simple structure, low implementation cost, small footprint, and a faster and simpler equipment installation and testing process, and is particularly suitable for products using split motors such as Stirling refrigerators; at the same time, the motor to be tested, the sound signal acquisition unit, and the vibration signal acquisition unit inside the soundproof box and the external motor control unit, sound signal processing unit, and vibration signal processing unit can all be connected by wired / wireless connection to transmit signals, and when connected by wire, it is only necessary to open a small through hole on the soundproof box for the cable to pass through, without opening a large hole-like structure, so as to avoid excessive leakage of energy in the soundproof box and cause signal loss;

[0092] Furthermore, the motor to be tested is assembled on a test fixture and is integrally connected to the test fixture on a frame located inside the sound insulation box. Therefore, there is no need to support the motor to be tested through motor supporting equipment arranged outside the box and large through holes opened on the sound insulation box, thereby eliminating the sound pressure data pollution caused by additional external excitation forces.

[0093] Embodiment 2:

[0094] The difference between this embodiment and embodiment 1 is that the test tool 3 further includes:

[0095] A bearing mounting member 11 is disposed in the internal accommodation space 311 and connected to the inner wall surface of the cylindrical body 31, and the bearing mounting member 11 is provided with a bearing chamber 111; in this embodiment, the bearing mounting member 11 can be integrally formed with the cylindrical body 31, and the first shaft extension end 321 passes through the bearing mounting member 11;

[0096] A first bearing 12, which is installed in the bearing chamber 111 and sleeved on the outer circumferential surface of the first shaft extension end 321;

[0097] A second bearing 13, which is installed in the end cover receiving groove 331 and sleeved on the outer circumferential surface of the second shaft extension end 322;

[0098] The spring 14 is sleeved on the outer circumference of the first shaft extension end 321, and the two ends thereof are respectively against the first bearing 12 and the shaft shoulder 3211 of the first shaft extension end 321;

[0099] In this embodiment, one or both of the first bearing 12 and the second bearing 13 are deep groove ball bearings, so that the two ends of the rotating shaft 21 can be supported by the bearings to ensure stable rotation, and the axial impact of the rotating shaft can be buffered by the spring.

[0100] Embodiment 3:

[0101] This embodiment provides a method for separating the electromagnetic characteristics of a motor according to Embodiment 1 or 2, such as Figure 5 As shown, it includes the following steps:

[0102] S1, assembling the motor 100 to be tested onto the test fixture 3, and placing the frame 2 connected with the test fixture 3 as a whole inside the soundproof box 1;

[0103] S2, through the control of the motor control unit 4, the motor power supply 10 supplies power to the stator 102 of the motor 100 to be tested, so as to generate an alternating magnetic field, and further drive the rotor 101 to start rotating through the magnetic field; at the same time, the sound signal acquisition unit 5 and / or the vibration signal acquisition unit 7 are turned on to correspondingly collect noise signals and vibration signals;

[0104] S3, after the speed of the motor 100 to be tested is accelerated from 0 to the maximum speed, the motor 100 to be tested works at the maximum speed for a predetermined time, and the motor 100 to be tested is powered off until the speed of the motor 100 to be tested is decelerated from the maximum speed to 0, and the sound signal acquisition unit 5 and / or the vibration signal acquisition unit 7 stop signal acquisition when the speed of the motor 100 to be tested is 0; the predetermined time can be determined according to factors such as the type of the motor 100 to be tested and the rotational inertia of the shaft, and in this embodiment, it can be 1-20 seconds;

[0105] S4, processing the noise signal through the acoustic signal processing unit 6 to obtain noise sound pressure level data, and / or, processing the vibration signal through the vibration signal processing unit 8 to obtain a vibration signal processing result;

[0106] S5. The data processing unit 9 performs electromagnetic noise feature separation according to the noise sound pressure level data, and / or performs electromagnetic vibration feature separation according to the vibration signal processing result.

[0107] Among them, Figure 6 As shown, the data processing unit 9 performs electromagnetic noise feature separation according to the noise sound pressure level data, including the following steps:

[0108] S51, import the noise sound pressure level data; the noise sound pressure level data in this embodiment can be stored and displayed in a matrix form, for example, with noise frequency and time as x and y axes, respectively, and sound pressure level data (in dB) as z axis, that is, Figure 7 As shown, "A", "B" and "uniform speed point" are all sound pressure level data;

[0109] S52, separating the acceleration stage sound pressure level data matrix A and the deceleration stage sound pressure level data matrix B from the noise sound pressure level data; wherein the acceleration stage refers to the stage in which the speed of the motor 100 to be tested is accelerated from 0 to the maximum speed, and the deceleration stage refers to the stage in which the speed of the motor 100 to be tested is decelerated from the maximum speed to 0; the stage in which the motor 100 to be tested works at the maximum speed for a predetermined time is the uniform speed stage, and there is no need to use the sound pressure level data in the uniform speed stage to separate electromagnetic noise;

[0110] S53, performing data preprocessing on both the acceleration phase sound pressure level data matrix A and the deceleration phase sound pressure level data matrix B, so that the dimensions and directions of the preprocessed acceleration phase sound pressure level data matrix A and the deceleration phase sound pressure level data matrix B are consistent;

[0111] Specifically, the data pre-processing of the acceleration stage sound pressure level data matrix A includes:

[0112] Part of the sound pressure level data is removed from the acceleration stage sound pressure level data matrix A, so that the dimensions of the acceleration stage sound pressure level data matrix A and the deceleration stage sound pressure level data matrix B are consistent; in this embodiment, the sound pressure level data can be removed by random removal or by removing one row for every n rows, so that the dimensions of the acceleration stage sound pressure level data matrix A and the deceleration stage sound pressure level data matrix B after the data removal are consistent (including the same number of matrix rows and columns), for example Figure 6 As shown, both are matrices of 5 rows × 8 columns;

[0113] The data pre-processing of the sound pressure level data matrix B during the deceleration phase includes:

[0114] Rotate the sound pressure level data matrix B of the deceleration phase 180° clockwise;

[0115] The sound pressure level data matrix B of the deceleration phase that has completed the clockwise rotation is flipped left and right once, so that the sound pressure level data matrix A of the acceleration phase and the sound pressure level data matrix B of the deceleration phase that have been pre-processed are in the same direction on the time axis;

[0116] S54, the sound pressure level data in the pre-processed acceleration phase sound pressure level data matrix A and the deceleration phase sound pressure level data matrix B are back-calculated and restored to the acceleration phase sound pressure data matrix A' and the deceleration phase sound pressure data matrix B' respectively; since the sound pressure level data cannot be used for matrix calculation, the sound pressure level needs to be back-calculated into sound pressure according to Lp=20*lg(p / p0), where Lp is the sound pressure level, P is the sound pressure, p0 is the reference sound pressure, 2×10 -5 Power (Pa);

[0117] S55, subtracting the acceleration phase sound pressure data matrix A' and the deceleration phase sound pressure data matrix B' to obtain a sound pressure difference matrix C;

[0118] S56. Assign a very small positive number to the value less than 0 in the sound pressure difference matrix C, and then convert the sound pressure into a sound pressure level according to Lp=20*lg(p / p0). The sound pressure level data is the electromagnetic noise characteristic of the motor. At the same time, the electromagnetic noise characteristic of the motor can be displayed in a visual way. For example, in this embodiment, the electromagnetic noise characteristic waterfall diagram of the motor (i.e. Figure 7 The motor electromagnetic noise characteristics are displayed in the form of "Separated motor electromagnetic noise characteristics waterfall diagram" in the figure.

[0119] Furthermore, the data processing unit 9 performs electromagnetic vibration feature separation according to the vibration signal processing result, including the following steps:

[0120] S51', import a vibration signal processing result (i.e., one of the displacement, displacement velocity, and acceleration); the vibration signal processing result in this embodiment can be stored and displayed in a matrix form, for example, with vibration frequency and time as the x and y axes, respectively, and acceleration (unit m / s 2 ) is the z-axis, that is, Figure 7 As shown, "D", "E" and "uniform speed point" are all acceleration data;

[0121] S42', separating the acceleration phase vibration data matrix D and the deceleration phase vibration data matrix E from the vibration signal processing result; wherein the meanings of the acceleration phase, deceleration phase, and uniform speed phase are the same as those in step S52, and will not be repeated;

[0122] S43', performing data preprocessing on both the acceleration phase vibration data matrix D and the deceleration phase vibration data matrix E, so that the dimensions and directions of the preprocessed acceleration phase vibration data matrix D and the deceleration phase vibration data matrix E are consistent;

[0123] Specifically, the data pre-processing of the acceleration phase vibration data matrix D includes:

[0124] Part of the vibration signal processing results are eliminated from the acceleration phase vibration data matrix D, so that the dimensions of the acceleration phase vibration data matrix D and the deceleration phase vibration data matrix E are consistent; in this embodiment, random elimination or the rule of eliminating one row for every n rows can be used to complete the elimination of the vibration signal processing result data, so that the dimensions of the acceleration phase vibration data matrix D and the deceleration phase vibration data matrix E after the data elimination are consistent (including the same number of matrix rows and columns), for example Figure 8 As shown, both are matrices of 5 rows × 8 columns;

[0125] The data pre-processing of the vibration data matrix E in the deceleration stage includes:

[0126] Rotate the vibration data matrix E of the deceleration phase 180° clockwise;

[0127] The vibration data matrix E of the deceleration phase that has completed clockwise rotation is flipped left and right once, so that the vibration data matrix D of the acceleration phase that has been pre-processed and the vibration data matrix E of the deceleration phase are in the same direction on the time axis;

[0128] S44', subtracting the acceleration phase vibration data matrix D after data pre-processing and the deceleration phase vibration data matrix E after data pre-processing to obtain a vibration data difference matrix F;

[0129] S45', assigning a very small positive number to the value less than 0 in the vibration data difference matrix F, and the vibration signal processing result in the vibration data difference matrix F is the electromagnetic vibration feature of the motor. At the same time, the electromagnetic vibration feature of the motor can be displayed in a visual way. For example, in this embodiment, the electromagnetic vibration feature waterfall diagram of the motor (i.e. Fig. 9 The electromagnetic vibration characteristics of the motor are displayed in the form of "Waterfall diagram of electromagnetic vibration characteristics of the motor after separation" in the figure.

[0130] In summary, the motor electromagnetic noise characteristic separation device in the present invention has a simple structure, low implementation cost, small footprint, and a faster and simpler equipment installation and testing process, and is particularly suitable for products using split motors such as Stirling refrigerators; at the same time, the motor to be tested, the sound signal acquisition unit, and the vibration signal acquisition unit inside the soundproof box and the external motor control unit, sound signal processing unit, and vibration signal processing unit can all be connected by wired / wireless connection to transmit signals, and when connected by wire, it is only necessary to open a small through hole on the soundproof box for the cable to pass through, without opening a large hole-like structure, so as to avoid excessive energy leakage in the soundproof box and cause signal loss;

[0131] Furthermore, the motor to be tested is assembled on the test fixture, and is integrally connected with the test fixture on a frame located inside the soundproof box, so that the motor to be tested does not need to be supported by a motor support device arranged outside the box and a large through hole opened on the soundproof box, thereby preventing the sound pressure data pollution caused by the extra external exciting force; at the same time, the present invention can make the motor still run for a certain period of time under the action of inertia after the power is turned off by correspondingly improving the rotational inertia of the rotating shaft, so as to ensure that the signal acquisition data is sufficient and the resolution is high enough;

[0132] When separating the electromagnetic noise characteristics and electromagnetic vibration characteristics of the motor, it can automatically achieve aligned slicing of the data before and after power failure (i.e. separation of the data in the acceleration phase and deceleration phase), data processing, matrix calculation and visualization result output, providing an effective and targeted test and evaluation method for motor fault diagnosis and vibration and noise reduction optimization.

[0133] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A motor electromagnetic characteristic separation device, characterized in that: include: Soundproof box; A test fixture, which is arranged inside the soundproof box and is used to install the motor to be tested; An acoustic signal processing unit is disposed outside the soundproof box and is used to process the noise signal generated when the motor to be tested is working to obtain noise sound pressure level data; A vibration signal processing unit is arranged outside the sound insulation box and is used to process the vibration signal generated when the motor to be tested is working to obtain a vibration signal processing result; and a data processing unit connected to the acoustic signal processing unit and / or the vibration signal processing unit, for performing electromagnetic noise feature separation according to the noise sound pressure level data, and / or performing electromagnetic vibration feature separation according to the vibration signal processing result.

2. The motor electromagnetic characteristic separation device according to claim 1, characterized in that: The test tooling comprises: A cylindrical body having an internal accommodation space, a first open end and a second open end; A rotating shaft, comprising a rotating shaft body and a first rotating shaft extending end and a second rotating shaft extending end correspondingly connected to two ends of the rotating shaft body, wherein the rotating shaft body is accommodated in the internal accommodation space of the cylindrical body, the first rotating shaft extending end extends toward the first opening end, and the second rotating shaft extending end extends toward the second opening end; an end cover connected to the cylindrical body, used to close the second open end, and having an end cover receiving groove for receiving the extended end of the second rotating shaft; The rotor of the motor to be tested is connected to the outer peripheral surface of the extended end of the first rotating shaft and extends axially into the first opening end. The stator of the motor to be tested extends axially into the first opening end and is connected to the cylindrical body.

3. The motor electromagnetic characteristic separation device according to claim 2, characterized in that: The moment of inertia of the rotating shaft satisfies the following conditions: J=(Tmax / 1000)*t / (ω*1000) Wherein, J is the moment of inertia; Tmax is the stall torque of the motor to be tested; t is the electromechanical time constant of the motor to be tested; ω is the no-load angular velocity of the motor to be tested.

4. The motor electromagnetic characteristic separation device according to claim 2, characterized in that: The test tool also includes: A mounting member is connected to the cylindrical body and is used to connect the testing tool as a whole to the frame.

5. The motor electromagnetic characteristic separation device according to claim 2, characterized in that: The test tool also includes: A bearing mounting member, which is arranged in the internal accommodation space and connected to the inner wall surface of the cylindrical body, and the bearing mounting member is provided with a bearing chamber; A first bearing, which is installed in the bearing chamber and sleeved on the outer peripheral surface of the extending end of the first rotating shaft; and a second bearing, which is installed in the end cover receiving groove and sleeved on the outer peripheral surface of the extending end of the second rotating shaft.

6. The motor electromagnetic characteristic separation device according to claim 6, characterized in that: The test tool also includes: The spring is sleeved on the outer peripheral surface of the extended end of the first rotating shaft, and the two ends thereof are respectively corresponding to the first bearing and the shaft shoulder of the extended end of the first rotating shaft.

7. The motor electromagnetic characteristic separation device according to claim 1, characterized in that: The inner wall surface and / or the outer wall surface of the sound insulation box are connected with sound insulation material.

8. A method for separating electromagnetic characteristics of a motor, characterized in that: The steps include: Assembling the motor to be tested onto the test fixture, and placing the entire frame connected with the test fixture inside the soundproof box; The motor control unit controls the stator of the motor to be tested to supply power, and the motor rotor is driven to start rotating through the magnetic field; at the same time, the sound signal acquisition unit and / or the vibration signal acquisition unit are turned on to correspondingly collect noise signals and vibration signals; After the speed of the motor to be tested is accelerated from 0 to the maximum speed, the motor to be tested operates at the maximum speed for a predetermined time, and the motor to be tested is powered off until the speed of the motor to be tested is decelerated from the maximum speed to 0, and the sound signal acquisition unit and / or the vibration signal acquisition unit stops signal acquisition when the speed of the motor to be tested is 0; Processing the noise signal to obtain noise sound pressure level data, and / or processing the vibration signal to obtain a vibration signal processing result; Electromagnetic noise feature separation is performed according to the noise sound pressure level data, and / or electromagnetic vibration feature separation is performed according to the vibration signal processing result.

9. The method for separating the characteristics of the motor electromagnetic noise according to claim 8, characterized in that: Performing electromagnetic noise feature separation according to the noise sound pressure level data includes the following steps: Importing the noise sound pressure level data, and storing the noise sound pressure level data in a matrix form; Separate the acceleration phase sound pressure level data matrix A and the deceleration phase sound pressure level data matrix B from the noise sound pressure level data; Data preprocessing is performed on both the acceleration phase sound pressure level data matrix A and the deceleration phase sound pressure level data matrix B, so that the dimensions and directions of the preprocessed acceleration phase sound pressure level data matrix A and the deceleration phase sound pressure level data matrix B are consistent; The sound pressure level data in the pre-processed acceleration stage sound pressure level data matrix A and the deceleration stage sound pressure level data matrix B are back-calculated and restored to the acceleration stage sound pressure data matrix A' and the deceleration stage sound pressure data matrix B' respectively; Subtract the acceleration phase sound pressure data matrix A' and the deceleration phase sound pressure data matrix B' to obtain a sound pressure difference matrix C; The values ​​less than 0 in the sound pressure difference matrix C are assigned a very small positive number, and the sound pressure is converted into a sound pressure level. The sound pressure level data is the electromagnetic noise characteristic of the motor.

10. The method for separating the characteristics of the motor electromagnetic noise according to claim 8, characterized in that: The electromagnetic vibration feature separation is performed according to the vibration signal processing result, comprising the following steps: Importing vibration signal processing results, and storing the vibration signal processing results in a matrix form; Separating the acceleration phase vibration data matrix D and the deceleration phase vibration data matrix E from the vibration signal processing results; Performing data preprocessing on both the acceleration phase vibration data matrix D and the deceleration phase vibration data matrix E, so that the dimensions and directions of the preprocessed acceleration phase vibration data matrix D and the deceleration phase vibration data matrix E are consistent; Subtracting the acceleration phase vibration data matrix D after data pre-processing and the deceleration phase vibration data matrix E after data pre-processing to obtain a vibration data difference matrix F; The values ​​less than 0 in the vibration data difference matrix F are assigned to extremely small positive numbers, and the vibration signal processing result in the vibration data difference matrix F is the electromagnetic vibration characteristic of the motor.

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