EMS-Elongation Measurement System

EMS Load-reduced turbine control (IPC)
Strain measurement system for supporting load-reduced turbine control (IPC)

Modern wind turbines (WT) are subject to stronger loads due to turbulent wind flows and the ever increasing size of rotors. The individual pitch control (IPC) can optimize the load on individual components which causes material fatigue. The EMS strain measurement system is used in this process to continuously and efficiently support the WT control unit: The ESR 125 sensors measure the strains that occur in the root area of the rotor blade. The EMS fieldbus CPU, which can be installed in the pitch cabinet for example, relies on scalable sensor sampling rate to check the plausibility of the measurement data in real time. Measured and pre-processed data can be sent directly to the pitch system or the WT control unit via a fieldbus interface.
EMS Measurement campaigns
Strain measurement system for design validation and prototype measurement

Strain measurements of design-specific structures are required for wind turbine certification in accordance with guidelines and ­standards such as DNV-GL, IEC or DIBt. By placing ESR 125 sensors on load dimensioned components, strains/loads can be measured with high precision and then compared with numerical simulations for validation purposes. In addition, local strain measurements can be used to evaluate mechanical stresses – the optimal basis for internal validations and further development. Unlike strain ­measurement systems, ESR sensors can also measure critical crack growth. To compensate for surface imperfections, ESR 125 sensors have a wider measurement range and longer measurement distance. A sampling rate of up to 100 kHz allows the analysis of highly dynamic movements.