KE or KN detection method and device of direct current brushless permanent magnet motor

Abstract

The invention relates to a KE or KN detection method and device for a direct-current brushless permanent magnet motor, and the method comprises the following steps: 1), the motor is powered on and automatically operates at a stable rotating speed, and a back electromotive force original signal P1 in a stable rotating speed period is collected; (2) the motor is powered off, X real-time counter electromotive force amplitudes P (X) are collected within the finite time from self-running to running stop of the motor depending on inertia during power failure, an envelope diagram of a counter electromotive force original signal is formed, the instantaneous phase is obtained, and the instantaneous frequency or the rotating speed is obtained; 3) a counter electromotive force constant KE is calculated; and 4) a rotating speed constant KN is calculated. Compared with the prior art, the method has the advantages that the tested motor does not need to be connected in a twin-dragging mode, time and labor are saved, testing is reliable, full-digital processing is achieved, and the economic value is remarkable.

Description

technical field [0001] The invention relates to a detection technology of electrical performance parameters of a motor, in particular to a detection method and device for a KE (counter electromotive force constant) or KN (rotational speed constant) of a DC brushless permanent magnet motor. Background technique [0002] As long as the motor is rotating, there must be a coil cutting the magnetic force line, so there will be a back electromotive force. For a specific type of motor, the faster the rotation speed, the higher the generated back electromotive voltage. That is, the back EMF voltage is proportional to the motor speed. The counter electromotive force constant KE is used to express this proportional relationship. For a specific motor, as long as any one of the two parameters of the back electromotive force constant KE and the torque constant KT is known, the other is known, and the key electrical performance parameters such as the output torque and speed of the motor...

AI Technical Summary

Problems solved by technology

[0007] Existing technology 1) The clamping motor is cumbersome, the test efficiency is low, the tester’s skill requirements are high, the repeatability of the test data is poor (subject to the concentricity of the prime mover and the output shaft of the motor under test), and the digital work cannot be automated. When the outer diameter of the output shaft of the motor under test is small or irregular, there is basically no connection method to ensure that the output shaft of the prime mover and the motor under test are concentric

[0008] Prior art 2) The clamping of the motor is cumbersome, and automatic clamping is easy to accidentally damage the rotating shaft of the motor under test. The repeatability of the test data is poor (subject to the concentricity of the prime mover and the output shaft of the motor under test), and the output shaft of the motor under test is encountered. When the diameter is small or irregular, there is basically no connection method to ensure that the output shaft of the prime mover and the motor under test are concentric

[0009] Neither of the above two methods can realize automatic digital detection, which is time-consuming and labor-intensive and has no economic benefits.

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