Wind turbine requirements for vibration sensors

Requirements for the vibration sensor of the wind turbine: To measure the vibration of the wind turbine, its vibration source must be analyzed first. The cause of the fan vibration is the rotation of the fan impeller and the unbalance and wear of the generator rotor. The rotor unbalance is the main vibration of the fan vibration One of the sources. Due to design and structural reasons, the rotor has mass eccentricity. When the rotor rotates, the vibration is caused by the centrifugal force generated by the mass eccentricity; or uneven materials, manufacturing and installation errors, wear and dust accumulation during use, make the fan The central inertial axis of the rotor often deviates from its rotational axis. These inertial forces will generate excessive additional dynamic pressure in the motion system, which will eventually be transmitted to the support bearings of the fan rotor. Periodic changes in the magnitude and direction of these inertial forces will destroy The balance of the fan rotor, causing vibration and noise to the fan, damage to the speed bearings and bearing seals, loose foundation of the fan or loose anchor screws of the coupling and motor, machining or assembly errors of each coupling and shaft, and wear or bending of each shaft.

According to statistics, the faults caused by rotor unbalance account for more than 80 percent of the faults of rotating machinery. In addition, there are rolling bearing damage, transmission belt damage, oil film whirl and oil film contact oscillation, excessive wind speed, instability, electrical reasons, pneumatic unbalance or Vibration caused by blade angle, etc. Secondly, wind turbines are generally located in low-temperature and windy sandy areas such as Northwest China, North China and Northeast China, or in humid and coastal high-corrosion areas in the South, and their locations are remote. This environmental characteristic requires the fan sensor to have low temperature resistance and high humidity , anti-wind and sand, corrosion resistance, stable performance, no maintenance and other good characteristics. Due to the harsh environment of wind turbines, higher requirements are placed on the monitoring system. However, the vibration sensor is the main equipment for signal acquisition, and its precision and accuracy The performance directly affects the quality of the monitoring system. Therefore, it is very necessary to choose a vibration sensor with good performance. On the one hand, the sensor has a good low-frequency response, and on the other hand, its natural frequency should be high to prevent resonance.

Finally, the signal collected by the vibration sensor is transmitted to the PLC. Through the judgment of STEP7 software programming, it can accurately judge whether the vibration of the wind turbine is out of tolerance, so as to avoid the long-term operation of the wind turbine at the resonant frequency, deal with the problem in time, and maintain it.