On-line methods to detect broken rotor bars in squirrel cage asynchronous motors

Rotor bar breaking is one of the frequent faults of the squirrel cage asynchronous motors. The spectrum analysis of the stator current, which is based on Fast Fourier Transform, is widely utilized to detect the fault on-line. The self-adaptive filter approach, the Park transform approach, the Hilbert transform approach and the instantaneous power approach are usually adopted. The theoretical principles and the experimental results of these methods are given in this paper, at the same time, by thoroughly analyzing experiment results, a series of interesting highlights to guarantee the sensitivity and reliability of the detection scheme for detecting broken rotor bar fault have been revealed explicitly. Furthermore, this paper reviews the four approaches, analyzes their advantages and deficiencies. Based on that, this paper also discusses the researching pivots in the future.