Device and method for testing short-circuit current of permanent magnet motor
By driving the permanent magnet motor, combined with real-time data acquisition and analysis of the computer module, the problem of inaccurate short-circuit current detection of permanent magnet motors in the prior art is solved, and high-accurate test results are achieved.
Patent Information
- Application Number
- CN202411666720.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-21
- Publication Date
- 2025-01-07
AI Technical Summary
In the prior art, the short-circuit current detection of permanent magnet motors is inaccurate, affected by the impedance of transformer and controller, and the speed attenuation during testing, resulting in distortion of the measurement results.
The motor under test is driven by a driving mechanism (servo motor), the short circuit and circuit breaker actions are controlled through the computer module, the current data is collected and analyzed in real time, and the real-time waveform diagram is generated to avoid the impact of the impedance of the transformer and controller, and to maintain the stable speed.
Ensure the authenticity and accuracy of the test results, avoid speed attenuation, provide accurate short-circuit current value and waveform data, and improve the reliability of the test.
Smart Images
Figure CN119269875A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of permanent magnet motor testing, and in particular to a permanent magnet motor short-circuit current testing device and method. Background Art
[0002] With the development of new energy vehicles, the advancement of industrial automation, and the country's emphasis on and call for energy conservation and emission reduction, the application of permanent magnet motors has become more and more extensive, gradually becoming a development trend in the motor industry.
[0003] On the one hand, the short-circuit current of the permanent magnet motor affects the maximum output power of the motor to a certain extent, and is an important parameter in the motor design. On the other hand, when the short-circuit current of the motor is large, it is also necessary to consider whether the permanent magnet of the permanent magnet motor will be irreversibly demagnetized when the motor is short-circuited, thereby affecting the performance of the permanent magnet motor. When the permanent magnet is irreversibly demagnetized, the permanent magnet motor will have problems such as reduced performance and reduced output power. In severe cases, it will also cause abnormal heating, burnout and fire, and even endanger property and life safety. Therefore, it is necessary to test and evaluate the short-circuit current of the permanent magnet motor to avoid the above situation.
[0004] The traditional short-circuit current test, according to the provisions of GB / T 755 "Ratings and Performance of Rotating Electrical Machines", is to operate the motor under no-load conditions through a transformer and / or controller drive mechanism at rated voltage, and then suddenly short-circuit the three-phase winding of the motor, and measure the short-circuit current of the motor at the moment of short-circuit. This method is affected by the impedance of the transformer and / or controller, resulting in distortion of the measurement results; in addition, because the tested motor is suddenly short-circuited and the speed decays instantly, the short-circuit current value tested at this time is not the short-circuit current value at the specified speed, and the test result is inaccurate. Summary of the invention
[0005] The purpose of the present invention is to solve the problem of inaccurate short-circuit current detection of permanent magnet motors in the prior art, and to propose a permanent magnet motor short-circuit current testing device and method.
[0006] In order to achieve the above object, the present invention adopts the following technical solutions:
[0007] A permanent magnet motor short-circuit current test device comprises a motor to be tested and a drive mechanism, wherein the motor to be tested and the drive mechanism are both connected to a computer module, a power output end of the drive mechanism is transmission-connected to a rotating part of the motor to be tested, the computer module can control the movement of the drive mechanism, the computer module can implement at least one of short-circuiting and disconnecting the motor to be tested, and the computer module can detect and analyze first data when the motor to be tested is in motion.
[0008] The first data is current data, and the computer module can analyze the current data and generate a first waveform diagram.
[0009] The first waveform diagram is a real-time waveform diagram of the current data, and the real-time waveform diagram includes an open circuit interval waveform and a short circuit interval waveform.
[0010] The short-circuit interval waveform in the real-time waveform diagram includes an oscillation area and a stable area, wherein the oscillation area is used to collect the maximum and minimum values of the short-circuit current, and the stable area is used to calculate the effective value of the short-circuit current;
[0011] And / or the computer module is capable of analyzing the current data and generating characteristic values, wherein the characteristic values include at least one of a maximum value, a minimum value, and an effective value of the current of the measured motor within a set time interval under a short-circuit state.
[0012] The driving mechanism is a servo motor, and the rotation speed fluctuation of the servo motor is ≤0.01%.
[0013] The driving mechanism is a servo motor, and the stable output torque of the servo motor at all test speeds is ≥1.2*the braking torque generated when the tested motor is short-circuited.
[0014] The computer module includes a computer, a data acquisition module, and a short-circuit / open-circuit module. The computer is electrically connected to the driving mechanism, the data acquisition module, and the short-circuit / open-circuit module, respectively. The data acquisition module and the short-circuit / open-circuit module are electrically connected to the motor under test, respectively. The computer can control the rotation speed of the driving mechanism. The computer can obtain current data of the motor under test when it is in motion through the data acquisition module and generate a waveform diagram of the current data. The computer can control the short-circuit and open-circuit of the motor under test through the short-circuit / open-circuit module.
[0015] The short-circuit / open-circuit module includes an electromagnetic relay electrically connected to a computer, and the electromagnetic relay can short-circuit or open-circuit the winding of the motor under test.
[0016] A method for testing short-circuit current of a permanent magnet motor comprises the permanent magnet motor short-circuit current testing device, and the testing method comprises the following steps: controlling the rotation of a driving mechanism by a computer, driving the motor under test to run to a specified speed and stably by the driving mechanism, controlling the action of a short-circuit / open-circuit module by a computer at a specified speed, causing the motor under test to perform at least one of short-circuit and open-circuit actions, while a data acquisition module acquires real-time values of the motor under test and feeds them back to the computer, and analyzing and generating a first waveform diagram of current data of the motor under test in a short-circuit and open-circuit state by the computer.
[0017] The first waveform diagram is a real-time waveform diagram, and the real-time waveform diagram includes an open circuit interval waveform and a short circuit interval waveform.
[0018] The present invention proposes a permanent magnet motor short-circuit current testing device and method, which have the following beneficial effects: the present invention uses a driving mechanism to drive the motor under test, and does not use a transformer and / or a controller, thereby fundamentally avoiding the influence of their impedance on the test results; the present invention uses a driving mechanism to drive the motor under test, so when the motor under test is short-circuited, there is no problem of speed attenuation, thereby ensuring the authenticity and accuracy of the test results. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a structural schematic diagram of the present invention;
[0020] Figure 2 It is a schematic diagram of the short-circuit current variation trend of the motor under test at different speeds of the present invention;
[0021] Figure 3 Schematic diagram of test data and waveforms of the present invention.
[0022] In the figure: computer 1, data acquisition module 2, short circuit / open circuit module 3, motor under test 4, driving mechanism 5. DETAILED DESCRIPTION
[0023] The technical solutions in the embodiments of the present invention will be described clearly and completely 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.
[0024] Reference Figure 1-Figure 3 A permanent magnet motor short-circuit current test device includes a motor 4 to be tested and a drive mechanism 5. The motor 4 to be tested and the drive mechanism 5 are both connected to a computer module. The power output end of the drive mechanism 5 is transmission-connected to the rotating part of the motor 4 to be tested. The computer module can control the movement of the drive mechanism 5. The computer module can perform at least one of short-circuiting and disconnecting the motor 4 to be tested. The computer module can detect and analyze the first data when the motor 4 to be tested is in action.
[0025] When the device is tested, the driving mechanism 5 drives the shaft of the motor 4 under test to rotate, so that the motor 4 under test rotates passively. During the process of the motor 4 under test being driven to rotate, the motor 4 under test is short-circuited, opened, and other operations are performed through the computer module, and then the computer module is used to detect and analyze the data of the motor 4 under test during its operation, such as short-circuit current data.
[0026] The present invention uses a driving mechanism to drive the motor under test, and does not use a transformer and / or a controller, thereby fundamentally avoiding the influence of their impedance on the test results;
[0027] The present invention uses a driving mechanism to drive the motor under test, so when the motor under test is short-circuited, there is no problem of rotation speed attenuation, thereby ensuring the authenticity and accuracy of the test result.
[0028] The first data is current data, and the computer module can analyze the current data and generate a first waveform diagram; the first waveform diagram is a real-time waveform diagram of the current data, and the real-time waveform diagram includes an open circuit interval waveform and a short circuit interval waveform, which can better reflect current data in various states.
[0029] The short-circuit interval waveform in the real-time waveform diagram includes an oscillation zone and a stable zone, wherein the oscillation zone is used to collect the maximum and minimum values of the short-circuit current, and the stable zone is used to calculate the effective value of the short-circuit current;
[0030] The computer module can analyze the current data and generate characteristic values, which include at least one of the maximum value, minimum value, and effective value of the current of the motor 4 under test within a set time interval under the short-circuit state, so as to facilitate the test personnel to view and judge.
[0031] The present invention can also measure the short-circuit current of the motor under test at multiple speeds, and continuously increase the test speed until the short-circuit current of the motor under test tends to be stable. Figure 2 As shown, the rationality of the magnetic circuit design of the motor under test can be judged.
[0032] The driving mechanism is a servo motor, and the speed fluctuation of the servo motor is ≤0.01%. The smaller the speed fluctuation of the servo motor, the more accurate the test result.
[0033] The driving mechanism is a servo motor, and the stable output torque of the servo motor at all test speeds is ≥1.2*the braking torque generated when the tested motor 4 is short-circuited. If the braking torque of the tested motor when it is short-circuited is greater than the output torque of the driving motor, the servo motor will lose steps or stall due to insufficient output torque when it is short-circuited. 1.2 times is the margin reserved under normal circumstances.
[0034] The computer module includes a computer 1, a data acquisition module 2, and a short-circuit / open-circuit module 3. The computer 1 is electrically connected to the driving mechanism 5, the data acquisition module 2, and the short-circuit / open-circuit module 3, respectively. The data acquisition module 2 and the short-circuit / open-circuit module 3 are electrically connected to the motor 4 under test, respectively. The computer 1 can control the rotation speed of the driving mechanism 5. The computer 1 can obtain the current data of the motor 4 under test when it is in action through the data acquisition module 2 and generate a waveform diagram of the current data. The computer 1 can control the short-circuit and open-circuit of the motor 4 under test through the short-circuit / open-circuit module 3.
[0035] The short-circuit / open-circuit module 3 includes an electromagnetic relay electrically connected to the computer 1 , and the electromagnetic relay can short-circuit or open-circuit the winding of the motor 4 under test.
[0036] A method for testing short-circuit current of a permanent magnet motor comprises the above-mentioned short-circuit current testing device of a permanent magnet motor, and the testing method comprises the following steps: controlling the rotation of a driving mechanism 5 by a computer 1, driving a motor 4 to be tested to run to a specified speed and stably by the driving mechanism 5, controlling the action of a short-circuit / open-circuit module 3 by the computer 1 at the specified speed, causing the motor 4 to perform at least one of short-circuit and open-circuit actions, while a data acquisition module 2 acquires real-time values of the motor 4 to be tested and feeds them back to the computer 1, and analyzing and generating a first waveform diagram of current data of the motor 4 to be tested in the short-circuit and open-circuit states by the computer 1.
[0037] The instantaneous value of the current is collected in real time through the computer module, and the real-time current waveform and data of the motor winding under test in the open circuit, short circuit and open circuit states are generated in real time. After the test is completed, the maximum value, minimum value and effective value in the specified waveform interval are calculated, and the waveform and data are stored. By observing and analyzing the waveform and data, it can be preliminarily judged whether there is an abnormality in the test result;
[0038] In order to make the test more accurate, the first waveform diagram is a real-time waveform diagram, and the real-time waveform diagram includes an open circuit interval waveform and a short circuit interval waveform.
[0039] As an implementation mode, the short circuit interval waveform may include a first short circuit interval waveform and a second short circuit interval waveform, and the short circuit interval waveform is located between the first short circuit interval waveform and the second short circuit interval waveform, wherein the first and the second are only for distinguishing the description and have no actual meaning.
[0040] refer to Figure 3 This method starts the current test under the condition of circuit break. At this time, because the winding of the motor under test is circuit-break, there is no current generated in the winding. The test is started at this time only to test the current change at the moment of short circuit. After the short circuit test, the circuit is broken again. Because the motor heats up seriously under the short circuit state, in order to avoid long-term short circuit, the circuit must be quickly disconnected after a period of short circuit. The short circuit time generally ensures that the current in each phase winding can stabilize to a certain value, which is generally stable within 5 to 50 electrical cycles. The specific value can be determined according to the waveform change of the current during the test or calculated according to the electrical cycle.
[0041] As an implementation method, the motor under test is installed on a test platform, and the servo motor is connected to the motor under test. The servo motor drives the motor under test to run at a specified speed; the short-circuit module is started to short-circuit the winding of the motor under test, and after running for a period of time (which can be set according to needs) in the short-circuit state, the winding is disconnected; the data acquisition module records the relevant current data in real time, and generates the corresponding curve and related characteristic values through a computer.
[0042] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technical solution, conception, and design obtained by equivalent replacement or modification of the technical solution and inventive concept of the present invention by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.
Claims
1. A permanent magnet motor short-circuit current test device, characterized in that: The invention comprises a motor to be tested (4) and a driving mechanism (5), wherein the motor to be tested (4) and the driving mechanism (5) are both connected to a computer module, the power output end of the driving mechanism (5) is drivingly connected to the rotating part of the motor to be tested (4), the computer module can control the movement of the driving mechanism (5), the computer module can implement at least one of short-circuiting and disconnecting the motor to be tested (4), and the computer module can detect and analyze first data when the motor to be tested (4) is in motion.
2. A permanent magnet motor short-circuit current testing device according to claim 1, characterized in that: The first data is current data, and the computer module can analyze the current data and generate a first waveform diagram.
3. A permanent magnet motor short-circuit current testing device according to claim 2, characterized in that: The first waveform diagram is a real-time waveform diagram of the current data, and the real-time waveform diagram includes an open circuit interval waveform and a short circuit interval waveform.
4. A permanent magnet motor short-circuit current test device according to claim 3, characterized in that: The short-circuit interval waveform in the real-time waveform diagram includes an oscillation area and a stable area, wherein the oscillation area is used to collect the maximum and minimum values of the short-circuit current, and the stable area is used to calculate the effective value of the short-circuit current; And / or the computer module is capable of analyzing the current data and generating a characteristic value, wherein the characteristic value includes at least one of a maximum value, a minimum value, and an effective value of the current of the measured motor (4) within a set time interval under a short-circuit state.
5. A permanent magnet motor short-circuit current test device according to claim 1, characterized in that: The driving mechanism is a servo motor, and the rotation speed fluctuation of the servo motor is ≤0.01%.
6. A permanent magnet motor short-circuit current test device according to claim 1, characterized in that: The driving mechanism is a servo motor, and the stable output torque of the servo motor at all test speeds is ≥ 1.2*the braking torque generated when the tested motor (4) is short-circuited.
7. A permanent magnet motor short-circuit current testing device according to any one of claims 1 to 6, characterized in that: The computer module comprises a computer (1), a data acquisition module (2), and a short-circuit / open-circuit module (3); the computer (1) is electrically connected to a driving mechanism (5), a data acquisition module (2), and a short-circuit / open-circuit module (3), respectively; the data acquisition module (2) and the short-circuit / open-circuit module (3) are electrically connected to a motor (4) to be tested, respectively; the computer (1) is capable of controlling the rotation speed of the driving mechanism (5); the computer (1) is capable of acquiring current data of the motor (4) to be tested when it is in motion through the data acquisition module (2) and generating a waveform diagram of the current data; and the computer (1) is capable of controlling the motor (4) to be tested to be short-circuited or open-circuited through the short-circuit / open-circuit module (3).
8. A permanent magnet motor short-circuit current testing device and method according to claim 7, characterized in that: The short-circuit / open-circuit module (3) comprises an electromagnetic relay electrically connected to the computer (1), and the electromagnetic relay is capable of short-circuiting or opening the winding of the motor (4) under test.
9. A method for testing short-circuit current of a permanent magnet motor, characterized in that: The invention comprises a permanent magnet motor short-circuit current test device as described in any one of claims 1 to 8, wherein the test method comprises the following steps: controlling the rotation of a driving mechanism (5) by a computer (1), driving the motor (4) under test to run to a specified speed and stably by the driving mechanism (5), controlling the action of a short-circuit / open-circuit module (3) by the computer (1) at the specified speed, causing the motor (4) under test to perform at least one of short-circuit and open-circuit actions, and at the same time, a data acquisition module (2) acquires the real-time value of the motor (4) under test and feeds it back to the computer (1), and a first waveform diagram of the current data of the motor (4) under the short-circuit and open-circuit states is analyzed and generated by the computer (1).
10. A permanent magnet motor short-circuit current testing device and method according to claim 9, characterized in that: The first waveform diagram is a real-time waveform diagram, and the real-time waveform diagram includes an open circuit interval waveform and a short circuit interval waveform.