Motor inductance testing device and method with automatic positioning function

Abstract

The invention discloses an automatic positioning motor inductance test device and method, and the device comprises a rack, and a mounting rack, a motor, a motor coil, a motor coil and a motor coil which are sequentially arranged in the X-axis direction, the driving unit is arranged on the mounting frame, and the output end is connected with a first coupler; the brake mechanism is arranged on the mounting frame and located on one side of the driving unit; one end of the transmission shaft is connected with the first coupler, and a shaft body is movably connected with the brake mechanism; the encoder is arranged on the shaft body of the transmission shaft; the mounting seat is arranged on the rack and used for mounting a tested motor, and a first support is further arranged on the mounting seat; one end of the test shaft is connected with the second coupler, a shaft body is connected with the tested motor, and the other end is movably connected with the first support through a bearing. Through the structure, accurate position control of the tested motor is realized, the influence of positioning errors on a measurement result is eliminated, meanwhile, compared with manual adjustment, the efficiency is improved, positioning can be rapidly completed, interference of human subjective factors is eliminated, the test precision is improved, and meanwhile, the repeatability of a test structure is good.

Description

Technical Field

[0001] This invention relates to the field of testing equipment technology, and in particular to an automatic positioning device and method for testing motor inductance. Background Technology

[0002] In the fields of motor design, manufacturing, and performance verification, d-axis inductance (Ld) and q-axis inductance (Lq) are core parameters characterizing the electromagnetic properties of a motor. Their accuracy directly determines the motor's torque control precision, energy efficiency, and operational stability. For example, in drive motors for new energy vehicles, measurement deviations in Ld / Lq can lead to increased torque pulsation, affecting vehicle ride smoothness. In industrial servo motors, deviations in this parameter can cause positioning errors to exceed tolerances, reducing the machining accuracy of automated equipment. In micro motors used in smart homes, it also directly relates to motor noise and energy consumption. Therefore, accurate testing of motor inductance is a crucial step in motor R&D, factory quality inspection, and fault diagnosis.

[0003] Currently, the mainstream method for testing motor inductance in the industry still mainly relies on "manual positioning + offline measurement." The specific process is as follows: the operator visually aligns the rotor with the marked lines, or uses simple mechanical fixtures (such as pins or positioning blocks) to initially fix the rotor to a preset angle. Then, an AC signal generator inputs a test signal to the motor windings, and voltage and current data are collected using an oscilloscope or multimeter to calculate the inductance value. However, this method has the following significant drawbacks: (1) Positioning accuracy is heavily dependent on manual operation and measurement error is large: When positioning manually, the operator needs to observe the alignment of the rotor mark with the tooling reference by visual observation. Affected by visual fatigue and differences in operation techniques, the deviation between the actual position of the rotor and the theoretical d-axis / q-axis can usually reach ±5°~±8°. Even if simple mechanical tooling is used, the positioning offset is caused by the fit clearance between the tooling and the motor shaft diameter (usually 0.1~0.3mm), which ultimately results in an inductance measurement error as high as 10%~15%, which cannot meet the testing requirements of high-precision motors (such as servo motors and permanent magnet synchronous motors).

[0004] (2) Low testing efficiency and difficult to adapt to mass production scenarios: For each motor under test, manual positioning requires repeated adjustment of the rotor position, and each positioning takes about 2 to 3 minutes. In addition to the time for signal acquisition and data calculation, the total testing time for a single motor can reach 5 to 8 minutes. In the mass quality inspection scenario of motor production line, this efficiency is far from matching the production line rhythm, causing the testing link to become a production bottleneck.

[0005] (3) Poor versatility and high adaptation cost: There are differences in shaft length, shaft diameter and rotor pole number of different motor models. Traditional manual positioning fixtures need to be designed separately for different motor models, which not only increases the cost of fixture manufacturing, but also requires frequent replacement of fixtures, further reducing testing efficiency; some special structure motors (such as non-discrete pole motors without rotor markings) cannot even be positioned by traditional manual methods, resulting in the failure of the test plan.

[0006] (4) Manual intervention leads to poor repeatability of test results: Different operators have different positioning techniques and signal acquisition timing. Even for the same motor, the inductance value of different operators can deviate by 5% to 8%. Even if the same operator tests multiple times, the results fluctuate due to slight differences in manual adjustment force and angle, making it impossible to form stable and reliable test data, which affects the accuracy of motor performance evaluation.

[0007] In summary, existing motor inductance testing methods suffer from low accuracy, poor efficiency, insufficient versatility, and poor repeatability due to the core limitation of "manual positioning," making it difficult to meet the current demands for high-precision, mass-production motor manufacturing and R&D. Therefore, developing a motor inductance testing device and method that can achieve automatic and precise rotor positioning, adapt to multiple motor models, and has high testing efficiency has become an urgent technical problem to be solved in this field. Summary of the Invention

[0008] This invention provides an automatic positioning motor inductance testing device, which aims to solve at least one of the technical problems existing in the prior art.

[0009] The first aspect of the present invention relates to an automatically positioned motor inductance testing device, comprising a test stand and components arranged sequentially along the X-axis direction: Mounting frame, provided on the aforementioned platform; A drive unit is provided on the mounting frame, and the output end of the drive unit is connected to a first coupling. A braking mechanism is provided on the mounting bracket and located on one side of the drive unit; The drive shaft is connected to the first coupling at one end, and the shaft body is movably connected to the brake mechanism. The other end is connected to the second coupling. The encoder is mounted on the shaft of the drive shaft and located on the side of the braking mechanism away from the drive unit; A mounting base is provided on the platform for mounting the motor under test. A first support is also provided on one side of the mounting base. The test shaft is connected to the second coupling at one end, the shaft body is connected to the motor under test, and the other end is movably connected to the first support through a bearing.

[0010] According to some embodiments of the present invention, the drive unit is a servo motor and the braking mechanism is an electromagnetic brake.

[0011] According to some embodiments of the present invention, a first sliding seat is further included, which is movably disposed on the platform along the X-axis direction, and the mounting seat and the first support are both disposed on the first sliding seat.

[0012] According to some embodiments of the present invention, the platform is provided with a guide rail along the X-axis direction, and the lower end of the first sliding seat is provided with a first slider that is slidably connected to the guide rail.

[0013] According to some embodiments of the present invention, the platform is further provided with a second sliding seat, the second sliding seat being disposed between the mounting base and the second coupling, and the lower end of the second sliding seat being provided with a second slider that is slidably connected to the guide rail.

[0014] According to some embodiments of the present invention, the frame is further provided with a rack along the X-axis direction, and the sides of the first sliding seat and the second sliding seat are respectively provided with handwheels. The handwheels are connected to gears through rotating shafts, and the gears mesh with the rack. The two handwheels are respectively used to drive the first sliding seat and the second sliding seat to move in the X-axis direction.

[0015] According to some embodiments of the present invention, the second sliding seat is further provided with a second support, and the shaft of the test shaft near the second coupling is movably connected to the second support through the bearing.

[0016] According to some embodiments of the present invention, the mounting bracket is further provided with a first mounting plate, a second mounting plate and a third mounting plate, and the drive unit, the braking mechanism and the encoder are respectively mounted on the first mounting plate, the second mounting plate and the third mounting plate.

[0017] The second aspect of the present invention relates to an automatic positioning method for testing the inductance of a motor, comprising the following steps: A. Drive the rotor of the motor under test to rotate at a constant speed, while simultaneously inputting a constant AC voltage signal to the windings of the motor under test, and acquiring the current signal of the windings in real time; B. Based on the current signal, obtain the maximum current point and the minimum current point of the winding, wherein the maximum current point corresponds to the rotor being at the d-axis position, to determine the first electrical angle corresponding to the rotor being at the d-axis position; the minimum current point corresponds to the rotor being at the q-axis position, to determine the second electrical angle corresponding to the rotor being at the q-axis position; C. Drive the motor under test according to the first electrical angle and the second electrical angle, so that the rotor rotates to the d-axis position or the q-axis position respectively, and then lock the rotor; D. Input a set sinusoidal current signal into the winding, and collect the voltage and current values ​​corresponding to the rotor at the d-axis position or the q-axis position. Based on the voltage and current values ​​corresponding to the rotor at the d-axis position or the q-axis position and the frequency of the sinusoidal current signal, determine the apparent power, active power, power factor and inductance value corresponding to the rotor at the d-axis position or the q-axis position, respectively.

[0018] According to some embodiments of the present invention, in step A, the rotor of the motor under test rotates at a constant speed, and the change in electrical angle of the rotor is not less than 180°.

[0019] According to some embodiments of the present invention, in step E, the inductance is calculated using the formula: L = (U / I) / (2πf), where L is the inductance, U is the voltage value corresponding to the rotor at the d-axis position or the q-axis position, I is the current value corresponding to the winding when the rotor is at the d-axis position or the q-axis position, and f is the frequency of the sinusoidal current signal; or In step E, the inductance can also be calculated by impedance analysis. The calculation formula is: Z=U / I, L=Im(Z) / (2πf), where U is the voltage value corresponding to the rotor when it is at the d-axis position or the q-axis position, I is the current value corresponding to the winding when the rotor is at the d-axis position or the q-axis position, f is the frequency of the sinusoidal current signal, Z is the impedance, L is the inductance, and Im(Z) is the imaginary part of the impedance.

[0020] The beneficial effects of this invention are as follows: 1. The test motor is driven to rotate by the drive unit and the specific position of the motor is obtained by the encoder. The combination of the two can achieve precise position control of the test motor and lock it by the braking mechanism to eliminate the influence of positioning error on the measurement results. At the same time, compared with manual adjustment, the efficiency is improved, the positioning can be completed quickly, the interference of human subjective factors is eliminated, the test accuracy is improved, and the test structure has good repeatability. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the automatic positioning motor inductance testing device according to an embodiment of the present invention (with hidden control cabinet). Figure 2 This is a structural schematic diagram of an automatically positioned motor inductance testing device (with hidden control cabinet) from another perspective of an embodiment of the present invention. Figure 3 This is a front view of an automatic positioning motor inductance testing device according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the electrical control system of an automatic positioning motor inductance testing device according to an embodiment of the present invention.

[0022] Icon labels: The frame is 100, the first sliding seat is 110, the first slider is 111, the guide rail is 120, the second sliding seat is 130, the second slider is 131, the second support is 132, the rack is 140, and the handwheel is 150. Mounting bracket 200, first coupling 210, first mounting plate 220, second mounting plate 230, third mounting plate 240; Braking mechanism 300, drive unit 310; Drive shaft 400, second coupling 410; Encoder 500; Mounting base 600, first support 610; Test axis 700; The tested motor is 800. Controller 900, driver 910, AC power supply 920, power analyzer 930. Detailed Implementation

[0023] The following will describe several embodiments of the present invention, including embodiments corresponding to the accompanying drawings. It should be understood that the drawings are used to assist in understanding the technical features and technical solutions of the present invention, and should not be construed as limiting the scope of protection of the present invention.

[0024] The following will provide a clear and complete description of the concept, specific structure, and technical effects of the present invention in conjunction with the embodiments and accompanying drawings, so as to fully understand the purpose, solution, and effects of the present invention. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0025] It should be noted that, unless otherwise explicitly defined, when a feature is referred to as "fixed," "connected," "installed," or "set" on another feature, it can be "fixed," "connected," "installed," or "set" directly on the other feature, or it can be "fixed," "connected," "installed," or "set" on the other feature indirectly. The terms "fixed," "connected," "installed," and "set" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0026] It should be noted that the descriptions of orientations or positional relationships indicated by terms such as up, down, left, right, top, bottom, front, back, inside, and outside used in this invention are based on the orientations or positional relationships indicated by the accompanying drawings or embodiments. They are only for the purpose of facilitating the description of this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0027] It should be noted that the term "and / or" as used in this invention includes any combination of one or more of the related listed items, "several" means one or more, "multiple" means at least two, "greater than", "less than", "exceeding" are understood to exclude the number itself, and "above", "below", "within" are understood to include the number itself.

[0028] It should be noted that the use of "first" and "second" in this invention is only for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features or the order of the technical features.

[0029] It should be noted that, unless otherwise expressly defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and not for limiting the invention.

[0030] like Figures 1 to 3 As shown, an embodiment of the first aspect of the present invention provides an automatic positioning motor inductance testing device, comprising a platform 100, and the following components arranged sequentially along the X-axis: a mounting frame 200 disposed on the platform 100; a drive unit 310 disposed on the mounting frame 200, the output end of the drive unit 310 being connected to a first coupling 210; a brake mechanism 300 disposed on the mounting frame 200 and located on one side of the drive unit 310; and a transmission shaft 400, one end of which is connected to the first coupling 210, the shaft body... The brake mechanism 300 is movably connected at one end, and the second coupling 410 is connected at the other end; the encoder 500 is located on the shaft of the drive shaft 400 and on the side of the brake mechanism 300 away from the drive unit 310; the mounting base 600 is located on the stand 100 and is used to mount the motor under test 800, and the mounting base 600 is also provided with a first support 610; the test shaft 700 is connected to the second coupling 410 at one end, the shaft body is connected to the motor under test 800, and the other end is movably connected to the first support 610 through a bearing.

[0031] In the above structure, the drive unit 310, brake mechanism 300, encoder 500, and tested motor 800 are all electrically connected to the controller 900. The controller 900 is located in a movable control cabinet with casters at the bottom. The controller 900, through the driver 910, instructs the drive unit 310 to rotate the encoder 500 and the tested motor 800. Simultaneously, a programmable variable frequency AC power supply 920 is electrically connected between the tested motor 800 and the controller 900. While rotating, the AC power supply 920 supplies a small constant AC voltage signal to the windings of the tested motor 800. The data acquisition card synchronously and at high speed acquires the current signal passing through the windings, forming a waveform based on the current signal. The controller 900 then analyzes the current waveform. After analysis, the maximum and minimum current points are identified, and the corresponding encoder 500 positions are determined, corresponding to the d-axis and q-axis positions, respectively. Then, the controller 900, through the driver 910, instructs the drive unit 310 to rotate the encoder 500 and the tested motor 800 until the encoder 500 reaches the corresponding d-axis or q-axis position. At this point, the brake mechanism 300 locks the transmission shaft 400, thereby locking the tested motor 800. This fundamentally eliminates the influence of positioning errors on the measurement results. Furthermore, the entire process requires no manual operation, eliminating reliance on manual intervention, improving testing accuracy and efficiency, and removing interference from subjective human factors, making it suitable for batch testing on production lines.

[0032] The above-mentioned automatic positioning motor inductance testing device has at least the following beneficial effects: the drive unit 310 drives the tested motor 800 to rotate, and the encoder 500 obtains the specific position of the tested motor 800. The combination of the two can achieve precise position control of the tested motor 800, and the brake mechanism 300 locks it, eliminating the influence of positioning error on the measurement results. At the same time, compared with manual adjustment, the efficiency is improved, positioning can be completed quickly, the interference of human subjective factors is eliminated, the test accuracy is improved, and the test structure has good repeatability.

[0033] According to some embodiments of the present invention, the drive unit 310 is configured as a servo motor.

[0034] According to some embodiments of the present invention, the braking mechanism 300 is configured as an electromagnetic brake.

[0035] According to some embodiments of the present invention, a first sliding seat 110 is further included. The first sliding seat 110 is movably disposed on the frame 100 along the X-axis direction. The mounting seat 600 is disposed on the first sliding seat 110. A guide rail 120 is provided on the frame 100 along the X-axis direction. A first slider 111 that is slidably connected to the guide rail 120 is provided at the lower end of the first sliding seat 110. A second sliding seat 130 is also provided on the frame 100. The second sliding seat 130 is disposed between the mounting seat 600 and the second coupling 410. A second slider 131 that is slidably connected to the guide rail 120 is provided at the lower end of the second sliding seat 130. By sliding and adjusting the first sliding seat 110 and the second sliding seat 130 on the guide rail 120, different specifications of the tested motor 800 can be installed and tested, enhancing the versatility of the entire testing device.

[0036] According to some embodiments of the present invention, a rack 140 is also provided on the stand 100 along the X-axis direction. Handwheels 150 are respectively provided on the sides of the first sliding seat 110 and the second sliding seat 130. The handwheels 150 are connected to gears through rotating shafts. The gears mesh with the rack 140. The two handwheels 150 are respectively used to drive the first sliding seat 110 and the second sliding seat 130 to move in the X-axis direction. The adjustment of the first sliding seat 110 and the second sliding seat 130 is carried out by the handwheels 150 in combination with the gear and rack 140, which makes the adjustment process smoother, and the adjustment method and distance are controllable. Real-time adjustment can be performed. The structure is simple and easy to operate.

[0037] According to some embodiments of the present invention, the second sliding seat 130 is further provided with a second support 132. The shaft of the test shaft 700 near the second coupling 410 is movably connected to the second support 132 through a bearing. Both the first support 610 and the second support 132 are provided with bearings for movably connecting the test shaft 700, so that the rotation of the test shaft 700 is not interfered with, while supporting the test shaft 700, ensuring the coaxiality of the test shaft 700 with the tested motor 800, the drive unit 310, and the transmission shaft 400. At the same time, the first coupling 210 and the second coupling 410 are used to ensure the coaxiality of the transmission shaft 400 with the above-mentioned structure.

[0038] According to some embodiments of the present invention, the mounting bracket 200 is further provided with a first mounting plate 220, a second mounting plate 230 and a third mounting plate 240 respectively. The drive unit 310, the brake mechanism 300 and the encoder 500 are respectively mounted on the first mounting plate 220, the second mounting plate 230 and the third mounting plate 240. The first mounting plate 220, the second mounting plate 230 and the third mounting plate 240 are respectively used to ensure that the axes of the drive unit 310, the brake mechanism 300 and the encoder 500 are at the same height, to ensure coaxiality and avoid affecting the test structure.

[0039] The second aspect of the present invention relates to an automatic positioning method for testing the inductance of a motor, comprising the following steps: A. Drive the rotor of the motor under test 800 to rotate at a constant speed, while simultaneously inputting a constant AC voltage signal to the winding of the motor under test 800, and acquiring the current signal of the winding in real time. B. Based on the current signal, obtain the maximum and minimum current points of the winding. The maximum current point corresponds to the rotor being at the d-axis position, to determine the first electrical angle corresponding to the rotor at the d-axis position; the minimum current point corresponds to the rotor being at the q-axis position, to determine the second electrical angle corresponding to the rotor at the q-axis position. C. Based on the first electrical angle and the second electrical angle, drive the tested motor 800 so that the rotor rotates to the d-axis position or the q-axis position respectively, and then lock the rotor. D. Input the set sinusoidal current signal into the winding, and collect the voltage and current values ​​corresponding to the rotor at the d-axis position or q-axis position. Based on the voltage and current values ​​corresponding to the rotor at the d-axis position or q-axis position and the frequency of the sinusoidal current signal, determine the apparent power, active power, power factor and inductance value corresponding to the rotor at the d-axis position or q-axis position respectively.

[0040] In step A, the controller 900 sends a command to the driver 910, which drives the rotor of the drive unit 310, transmission shaft 400, test shaft 700, and the motor under test 800 to rotate at a constant speed. The drive unit 310 is a servo motor. Simultaneously, the programmable AC power supply 920 inputs a constant AC voltage signal to the windings of the motor under test 800. The data acquisition card synchronously and at high speed acquires the current signal of the windings. In step B, the controller 900 analyzes the waveform of the current signal in real time to obtain the maximum and minimum current points flowing through the windings. The maximum current point corresponds to the rotor being at the d-axis position, thereby determining the first electrical angle corresponding to the rotor at the d-axis position. The encoder 500 on the transmission shaft 400 feeds back the corresponding position A and the minimum current point. When the rotor is at the q-axis position, the encoder 500 can provide feedback on the corresponding B position. In step C, the controller 900 sends a command to the driver 910 based on the corresponding data calculated in step B. The driver 910 drives the servo motor to rotate the rotor of the tested motor 800 by the first electrical angle. During the process, the encoder 500 can provide feedback on the A position to determine whether the rotation is complete. After rotating to the d-axis position, the brake mechanism 300 locks the transmission shaft 400 to lock the rotor of the tested motor 800, ensuring that the rotor of the tested motor 800 remains stationary and without deviation, thus eliminating the influence of positioning error on the measurement results. In step D, in addition to obtaining parameters such as apparent power, active power, and power factor through calculation, they can also be obtained through the power analyzer 930.

[0041] According to some embodiments of the present invention, in step A, the rotor of the motor under test 800 rotates at a constant speed and the change in electrical angle of the rotor is not less than 180°, so as to ensure that the maximum current value point and the minimum current value point can be obtained from the current waveform diagram.

[0042] According to some embodiments of the present invention, in step E, the inductance is calculated using the formula: L = (U / I) / (2πf), where L is the inductance, U is the voltage value corresponding to the rotor at the d-axis position or the q-axis position, I is the current value of the winding corresponding to the rotor at the d-axis position or the q-axis position, and f is the frequency of the sinusoidal current signal; or In step E, the inductance can also be calculated through impedance analysis. The calculation formula is: Z=U / I, L=Im(Z) / (2πf), where U is the voltage value corresponding to the rotor when it is in the d-axis position or the q-axis position, I is the current value corresponding to the winding when the rotor is in the d-axis position or the q-axis position, f is the frequency of the sinusoidal current signal, Z is the impedance, L is the inductance, and Im(Z) is the imaginary part of the impedance.

[0043] It should be noted that in this specification, terms such as "one embodiment", "some embodiments", "basic embodiment", and "extended embodiment" may be used to describe several embodiments of the present invention, and the specific features, structures, materials or characteristics in the several embodiments may be combined in accordance with the principles and spirit of the present invention.

[0044] Although some embodiments of the present invention have been shown and described in this specification, the present invention should not be limited to the above embodiments. As long as they achieve the technical effects of the present invention by the same or equivalent means, any changes, modifications, equivalent substitutions and equivalent variations of these embodiments within the spirit and principles of this disclosure, without departing from the principles and purpose of the present invention, should be included within the scope of protection of this disclosure and should be considered to fall within the protection scope of the present invention.

Claims

1. An automatic positioning motor inductance testing device, characterized in that, Includes the test stand (100), and the following components arranged sequentially along the X-axis: Mounting bracket (200) is provided on the platform (100); A drive unit (310) is provided on the mounting bracket (200), and the output end of the drive unit (310) is connected to a first coupling (210). A braking mechanism (300) is provided on the mounting bracket (200) and located on one side of the drive unit (310); A drive shaft (400) is connected at one end to the first coupling (210), and the shaft body is movably connected to the brake mechanism (300). The other end is connected to the second coupling (410). The encoder (500) is disposed on the shaft of the drive shaft (400) and located on the side of the brake mechanism (300) away from the drive unit (310); A mounting base (600) is provided on the platform (100) for mounting the motor under test (800). A first support (610) is also provided on one side of the mounting base (600). The test shaft (700) is connected to the second coupling (410) at one end, the shaft body is connected to the motor under test (800), and the other end is movably connected to the first support (610) through a bearing.

2. The automatic positioning motor inductance testing device according to claim 1, characterized in that, The drive unit (310) is a servo motor, and the braking mechanism (300) is an electromagnetic brake.

3. The automatic positioning motor inductance testing device according to claim 1, characterized in that, It also includes a first sliding seat (110), which is movably disposed on the platform (100) along the X-axis direction. The mounting seat (600) and the first support (610) are both disposed on the first sliding seat (110).

4. The automatic positioning motor inductance testing device according to claim 3, characterized in that, The platform (100) is provided with a guide rail (120) along the X-axis direction, and the lower end of the first sliding seat (110) is provided with a first slider (111) that is slidably connected to the guide rail (120).

5. The automatic positioning motor inductance testing device according to claim 4, characterized in that, The platform (100) is also provided with a second sliding seat (130), which is located between the mounting base (600) and the second coupling (410). The lower end of the second sliding seat (130) is provided with a second slider (131) that is slidably connected to the guide rail (120).

6. The automatic positioning motor inductance testing device according to claim 5, characterized in that, The frame (100) is also provided with a rack (140) along the X-axis direction. The first sliding seat (110) and the second sliding seat (130) are respectively provided with handwheels (150). The handwheels (150) are connected to gears through a rotating shaft. The gears mesh with the rack (140). The two handwheels (150) are respectively used to drive the first sliding seat (110) and the second sliding seat (130) to move in the X-axis direction.

7. The automatic positioning motor inductance testing device according to claim 5, characterized in that, The second sliding seat (130) is also provided with a second support (132), and the shaft of the test shaft (700) near the end of the second coupling (410) is movably connected to the second support (132) through the bearing.

8. The automatic positioning motor inductance testing device according to claim 1, characterized in that, The mounting bracket (200) is also provided with a first mounting plate (220), a second mounting plate (230) and a third mounting plate (240), and the drive unit (310), the brake mechanism (300) and the encoder (500) are respectively mounted on the first mounting plate (220), the second mounting plate (230) and the third mounting plate (240).

9. A method for automatically positioning motor inductance testing, characterized in that, Includes the following steps: A. Drive the rotor of the motor under test (800) to rotate at a constant speed, and at the same time input a constant AC voltage signal to the winding of the motor under test (800), and collect the current signal of the winding in real time; B. Based on the current signal, obtain the maximum current point and the minimum current point of the winding, wherein the maximum current point corresponds to the rotor being at the d-axis position, to determine the first electrical angle corresponding to the rotor being at the d-axis position; the minimum current point corresponds to the rotor being at the q-axis position, to determine the second electrical angle corresponding to the rotor being at the q-axis position; C. Based on the first electrical angle and the second electrical angle, drive the tested motor (800) so that the rotor rotates to the d-axis position or the q-axis position respectively, and then lock the rotor; D. Input a set sinusoidal current signal into the winding, and collect the voltage and current values ​​corresponding to the rotor at the d-axis position or the q-axis position. Based on the voltage and current values ​​corresponding to the rotor at the d-axis position or the q-axis position and the frequency of the sinusoidal current signal, determine the apparent power, active power, power factor and inductance value corresponding to the rotor at the d-axis position or the q-axis position, respectively.

10. The method for automatically positioning motor inductance testing according to claim 9, characterized in that, In step A, the rotor of the tested motor (800) rotates at a constant speed, and the change in electrical angle of the rotor is not less than 180°.

11. The method for automatically positioning motor inductance testing according to claim 9 or 10, characterized in that, In step E, the inductance is calculated using the formula: L = (U / I) / (2πf), where L is the inductance, U is the voltage value corresponding to the rotor at the d-axis or q-axis position, I is the current value of the winding corresponding to the rotor at the d-axis or q-axis position, and f is the frequency of the sinusoidal current signal; or In step E, the inductance can also be calculated by impedance analysis. The calculation formula is: Z=U / I, L=Im(Z) / (2πf), where U is the voltage value corresponding to the rotor when it is at the d-axis position or the q-axis position, I is the current value corresponding to the winding when the rotor is at the d-axis position or the q-axis position, f is the frequency of the sinusoidal current signal, Z is the impedance, L is the inductance, and Im(Z) is the imaginary part of the impedance.

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