Diseño de un Sistema de Monitoreo de Vibraciones Mecánicas en Generadores Hidroeléctricos de Media Potencia

The objective of the research was to elaborate a methodology aimed at monitoring and forecasting the actual condition of a medium power hydroelectric generator. The proposed procedure was based on the continuous monitoring of the energetic behavior of the vibration signals, using accelerometers with output proportional to the general speed vibration level. The variable considered is the RMS value of the vibration velocity referential to the amount of fatigue stress. Through virtual instrumentation, the signals were processed and converted into a numerical value, defining the upper and lower limits for each of the critical zones (A, B, C, D) according to the parameters described in the STN ISO 10816 standard. Measurements and historical records were made over 3 weeks, during this evaluation period the generator operated at 80% of its capacity, and a wave spectrum with constant trend within the same range of values ranging from 0.21 to 1.79 mm/s (for the axial axis) and 0.39 to 2.23 mm/s (for the radial axis) was visualized, it was concluded that these values do not exceed the RMS value of the range 0.71 to 2.80 mm/s. Defining that the real state of the rotating machine at present is within the criticality limits of zone A (new or reconditioned machine), due to the fact that two years ago the generation group was subjected to maintenance works, where several elements of the equipment were repaired, in which the change of impellers and the replacement by a turbine with more blades stands out, guaranteeing at least a normal operation in this zone during the following 6 years.