The researchers aimed to detect early bearing damage in wind turbines using vibration analysis. They intentionally damaged bearings to simulate faults and analyzed the vibration spectrum. Normal bearings showed no damage frequency, but high frequencies from shaft rotation. Damaged bearings exhibited distinct fault frequencies in the outer and inner raceways, hidden by other components in the frequency spectrum. Envelope analysis revealed low-energy impacts and highlighted the fault frequencies clearly. This method effectively identified multi-fault bearing damage in wind turbines.