Diagnosis Method for Hydro-generator Rotor Fault Based on Stochastic Resonance

Abstract

The rotor of hydro-generator is in the state of rotary vibration. Rotor faults is a common fault in hydrogenerators. The fault is not easy to detect in the early stage, but with the development of the fault, it will pose a threat to the safe operation of hydro-generator. Many faults will change the vibration of generator rotor. In order to detect small fault signals, time frequency compression stochastic resonance method (FCSR) is proposed. This method uses vibration noise to enhance weak fault signal characteristics. The frequency range of stochastic resonance can be improved by the time-frequency compression algorithm. The algorithm eliminates the limitation of the system on the measurement signal frequency and extends the stochastic resonance system to the whole frequency band. In addition, according to the rotor vibration of the hydro-generator, the range of the relevant parameters of the method is improved. The stochastic resonance method is used to reduce the noise of hydrogenerator rotor vibration signal and improve the signal-to-noise ratio of the signal. This is conducive to the extraction of rotor fault feature vectors. The results show that the method can accurately identify the abnormal vibration of hydro-generator and has high rotor early fault diagnosis accuracy.