Method for detecting broken bar fault of cage type asynchronous motor rotor based on multiple signal classification (MUSIC) and pattern search algorithm (PSA)

Abstract

The invention discloses a method for detecting broken bar fault of a cage type asynchronous motor rotor based on multiple signal classification (MUSIC) and a pattern search algorithm (PSA). The method comprises the following steps of: firstly, applying a multiple signal classification technique to obtain frequency values of a fundamental component and a side frequency component of a stator current momentary signal which is acquired according to a certain frequency; secondly, estimating amplitude values and initial phase angles of the fundamental component and side frequency component of the stator current momentary signal by applying the PSA; thirdly, calculating the ratio of the amplitude value of the current side frequency component to that of the fundamental component and taking the ratio as a fault characteristic; fourthly, calculating the specific value of the ratio to a detection threshold value to determine a fault index; and finally, judging whether a rotor broken bar fault exists according to the fault index. By using the method, the broken bar fault of the asynchronous motor rotor can be detected in an on-line manner with high sensibility and high reliability by using few stator current signal sampling points, so the influence caused by adverse factors such as load fluctuation, noise and the like is effectively overcome, and the method is very suitable for the condition that an asynchronous motor runs at a low slip ratio.

Description

technical field [0001] The invention relates to a method capable of detecting broken bar faults of a cage-type asynchronous motor rotor on-line, and belongs to the detection technical field. Background technique [0002] During the operation of the cage-type asynchronous motor, the rotor guide bars are subjected to alternating stresses such as radial electromagnetic force, rotating electromagnetic force, centrifugal force, thermal bending deflection force, etc., and rotor manufacturing defects may lead to broken bars. Such failures The probability of occurrence is about 15%. [0003] Broken rotor bars are a typical progressive fault. Usually one or two guide bars break at the initial stage, and then gradually develop until the output of the motor decreases or even shuts down. Therefore, on-line detection of broken rotor bars must be implemented. [0004] After the broken rotor bars of cage-type asynchronous motors occur, there will be The frequency of the additional curr...

AI Technical Summary

Problems solved by technology

In engineering practice, disturbances such as load fluctuations or noise are unavoidable. Too long signal acquisition time often means introducing these disturbances and affecting the results of Fourier spectrum analysis, and even worsening the performance of rotor broken bar fault detection, and even failure

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