Detecting Generator Faults Using both Electrical and Mechanical Signals

Dominic Yellezuome, Isaac Osei


With the rapid growth of wind energy, increasing the availability and reliability of Wind Turbines (WT) will aid to boost energy production and minimise cost of energy. This paper presents a comparison of electrical and mechanical signals used in detecting both electrical and mechanical faults in induction generators. A series of experiments were conducted in steady state condition in order to obtain specific fault harmonic component present in the spectrum of the measured signals which are consistent and rise in magnitude with increasing generator speed when rotor winding imbalance and dynamic eccentricity were implemented on the test rig. This was then applied to a short period of variable speed condition. The spectral analysis was carried out using both Fast Fourier Transformation (FFT) and Continuous Wavelet Transform (CWT) algorithms to identify fault frequency components when faults were induced. The experimental results from the steady state condition shows a gradual rise in certain faulty frequency components magnitude with increasing speed. Rotor current was found to be very sensitive to rotor winding imbalance than vibration signal and vice versa when the test rig was operated under dynamic eccentricity condition. It was also revealed that the electrical and mechanical fault exhibit the same air gap flux distortion which reflected on the spectral analysis.


Induction Generator; Rotor Winding Imbalance; Dynamic Eccentricity; Current Signals; Vibration Signals

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