Monitoring magnetic poles of hydro generators using vibration data

This case study shows how a predictive maintenance programme was installed and used at the Cerrón Grande hydro plant, where unit 1 showed high vibrations on the generator bearing. A vibration analysis report concluded that generating poles were implicated. The recommendations were followed by the maintenance and OEM teams at site, who confirmed the fault, and then replaced or repaired seven poles of the 48 in this generator. After the maintenance works, the poles were restored to a good condition, and the vibration levels returned to acceptable levels.