SHM.Tower^® – Intelligent and Certified System for Monitoring Tower Vibrations and Maximizing Lifetime Extension

Depending on the location and mode of operation of a wind turbine (WTG), the vibration stress – especially on the tower – varies greatly. The monitoring system SHM.Tower records these stresses via an integrated sensor. Due to the permanent comparison of the current RMS-values with the applicable standards – e.g. ISO 10816-21 and VDI 3834 – the condition of the turbine is always visible at first glance. Turbine settings and operating mode can be continuously and proactively optimized. The system issues warning messages if predefined threshold values are exceeded. WTGs with excessive loads are thus immediately identified and countermeasures can be initiated.

Wind turbines are usually designed for a lifetime of 20 years. However, at the end of this design lifetime there is often a great potential for further operation. The decision on this is made within the scope of a lifetime extension report. So far, these are usually based on historical operating and wind data as well as turbulence reports. However, due to conservative load assumptions and insufficient consideration of the wind direction – and thus the distribution of lifetime consumption across the tower cross-section – the overall potential for a lifetime extension for as long as possible is often significantly underestimated.

SHM.Tower calculates the loads that actually occur and are distributed over the tower cross-section based on the accelerations measured in the tower and thus enables an exact statement to be made about the actual lifetime consumption. Even critical extreme conditions are directly recorded. Thus, the lifetime prognosis is no longer based on assumptions alone. The lifetime extension can be maximized and the entire yield potential can be tapped.

Sensors and electronics of SHM.Tower are built into a compact housing and allow for an easy installation in the tower head of the turbine. If the system is used right from the start, the operating status and the consumed lifetime are precisely recorded throughout all phases of use – thanks to the energy-autonomous mode even during construction and in the event of power failures. However, even if SHM.Tower is retrofitted, the system provides significantly improved lifetime assessments compared to conventional methods – even though the vibrations of the first years of operation are not recorded. Extrapolations enable the assessment over the entire service life.

After the initial lifetime extension report, you can optimally accompany the remaining service life of your WTG by continuously monitoring the vibration levels and tower loads.