Device suitable for measuring output torque of frequency converter

Abstract

The utility model relates to the technical field of frequency converters, in particular to a device suitable for measuring the output torque of a frequency converter, which comprises a motor frame, an asynchronous motor and a permanent magnet synchronous machine are arranged on the motor frame, and the output end of the asynchronous motor is in coaxial transmission with the permanent magnet synchronous machine through a motor coupler. The permanent magnet synchronous machine is connected with the torsion tester through a wire, the output end of the permanent magnet synchronous machine is provided with a motor shaft-to-encoder shaft torsion tester, one end of the motor frame is provided with an encoder mounting frame along the edge, and an encoder is mounted on the encoder mounting frame; the input end of the encoder is connected with the motor shaft-to-encoder shaft torsion tester through an encoder coupling, and the output end of the encoder is sequentially connected in series with a tested frequency converter and a matched testing frequency converter through wires. According to the testing scheme, the motor can be replaced according to the type of the frequency converter driving motor, so that the testing of multiple types of frequency converters can be realized; measurement operation is simple, and measurement precision is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of frequency converters, in particular to a device suitable for measuring the output torque of a frequency converter. Background Art

[0002] In modern industrial production, motor speed control is widely used in various fields. As an important speed control device, the performance of the frequency converter (VFD) has a crucial impact on the stability and efficiency of the production process. The output torque of the VFD is a key parameter, directly affecting the normal operation of the load driven by the motor. Therefore, measuring the output torque of the VFD has important application backgrounds.

[0003] In the prior art, the measuring device for the output torque of the frequency converter has the following defects and deficiencies:

[0004] 1. The installation is complicated, requiring special processing of the measured shaft, and is easily affected by environmental factors such as temperature and humidity;

[0005] 2. The accuracy is relatively low and is greatly affected by magnetic field interference;

[0006] 3. High cost and complicated installation and debugging;

[0007] 4. The inverter can drive a variety of motors, but only a single test motor type is available on the market.

[0008] Aiming at the above problems, an improvement is made and a device suitable for measuring the output torque of a frequency converter is proposed. Utility Model Content

[0009] The purpose of the utility model is to solve the shortcomings of the prior art and to propose a device suitable for measuring the output torque of a frequency converter.

[0010] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0011] A device suitable for measuring the output torque of a frequency converter includes a motor frame, on which an asynchronous motor and a permanent magnet synchronous machine are provided, the output end of the asynchronous motor is coaxially driven with the permanent magnet synchronous machine through a motor coupling, the permanent magnet synchronous machine is connected to a torque tester through wires, the output end of the permanent magnet synchronous machine is provided with a motor shaft rotation encoder shaft torque tester, an encoder mounting frame is provided along an edge of one end of the motor frame, an encoder is mounted on the encoder mounting frame, the input end of the encoder is connected to the motor shaft rotation encoder shaft torque tester through an encoder coupling, and the output end of the encoder is sequentially connected in series with a tested frequency converter and a matching frequency converter through wires.

[0012] The beneficial effects of the utility model are:

[0013] 1. According to the type of inverter drive motor, replacing the motor can realize multiple types of inverter testing.

[0014] 2. You only need to adjust the parameters on the inverter, observe the phenomenon, and record the data to achieve measurement. It is easy to operate and has high safety performance.

[0015] 3. High precision and strong anti-interference ability.

[0016] 4. Use motor for testing, which has long service life and the test platform is not easy to wear and aging. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the overall structure of the measuring device proposed in the present utility model.

[0018] In the figure: 1. Asynchronous motor; 2. Torque tester; 3. Motor coupling; 4. Motor frame; 5. Permanent magnet synchronous motor; 6. Motor shaft to encoder shaft torque tester; 7. Encoder coupling; 8. Encoder mounting bracket; 9. Encoder; 10. Inverter under test; 11. Matching inverter under test. DETAILED DESCRIPTION

[0019] 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.

[0020] In this embodiment, refer to Figure 1 A device suitable for measuring the output torque of a frequency converter includes a motor frame 4, on which an asynchronous motor 1 and a permanent magnet synchronous machine 5 are arranged. The output end of the asynchronous motor 1 is coaxially transmitted with the permanent magnet synchronous machine 5 through a motor coupling. The permanent magnet synchronous machine 5 is connected to a torque tester 2 through wires. The output end of the permanent magnet synchronous machine 5 is provided with a motor shaft rotation encoder shaft torque tester 6. An encoder mounting frame 8 is provided along the edge of one end of the motor frame 4. An encoder 9 is installed on the encoder mounting frame 8. The input end of the encoder 9 is connected to the motor shaft rotation encoder shaft torque tester 6 through an encoder coupling 7. The output end of the encoder 9 is connected in series with a tested frequency converter 10 and a matching frequency converter 11 through wires.

[0021] This measuring device is used to perform torque testing. The specific test method is as follows:

[0022] S1. Static load test. Set the inverter to speed mode, set the operating frequency to 0, and test the inverter's electric torque upper limit (adjust the braking torque upper limit to a low value, such as 80%).

[0023] S2. Run the tested inverter and wait for it to run stably. Run the tested inverter and check whether it can start normally. Record the maximum value of the torque sensor. After the test, stop the tested inverter.

[0024] S3: If it can start, increase the upper limit of the electric torque and the upper limit of the braking torque of the inverter; if it cannot start, reduce them and repeat the above operation;

[0025] S4. When the tested inverter is in the critical state between normal startup and abnormal startup, record the upper limit of the braking torque of the tested inverter and the torque value on the torque tester. The static loading test is completed.

[0026] S5. Dynamic loading test. Set the torque mode of the inverter to a low value, such as 100%.

[0027] S6. Run the inverter under test and wait for it to stabilize. Run the inverter under test and record the inverter current, torque and speed values ​​on the torque sensor. Stop testing the inverter.

[0028] S7. If the inverter under test operates normally, increase the torque setting and repeat the operation. If one of the two inverters reports a fault or the torque setting reaches the maximum value, record the data and the dynamic loading test is completed.

[0029] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A device for measuring the output torque of a frequency converter, characterized in that: The invention comprises a motor frame (4), wherein an asynchronous motor (1) and a permanent magnet synchronous machine (5) are arranged on the motor frame (4), the output end of the asynchronous motor (1) is coaxially driven with the permanent magnet synchronous machine (5) through a motor coupling, the permanent magnet synchronous machine (5) is connected to a torque tester (2) through an electric wire, the output end of the permanent magnet synchronous machine (5) is provided with a motor shaft rotation encoder shaft torque tester (6), an encoder mounting frame (8) is arranged along an edge of one end of the motor frame (4), an encoder (9) is mounted on the encoder mounting frame (8), the input end of the encoder (9) is connected to the motor shaft rotation encoder shaft torque tester (6) through an encoder coupling (7), and the output end of the encoder (9) is sequentially connected in series with a tested frequency converter (10) and a matching frequency converter (11) through electric wires.

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