Digital strain measurement for wind turbines -
Optimizing the control & condition monitoring

Robust and stable strain sensor for sustained use.

The ESR strain sensor is based on an industrial sensor technology that has already been installed a million times over - optimally adapted to meet the high demands of wind turbines. The ESR x25 is designed to measure with zero force to prevent fatigue in the measuring section. The strain sensor features quick, easy and safe installation and can be adapted to the material of the surface to be measured. This allows the sensor to expand along with the material and, as a result, automatically provides passive temperature compensation.

DIGITAL ROBUST STRAIN SENSOR FOR LONG-TERM OPERATION

HIGH PRECISION

Temperature compensation by adapted measurement arm
Best in class sensor resolution 0.025 µɛ and measuring range ± 5000 µɛ
Sampling frequency range up to 100 kHz
Temperature check
Sensor range reserve
Plausibility checks

INTEGRATED DIAGNOSTICS

Protection Class IP64
Lightning protection acc. IEC61400-24
Stressless measurement: fatigue-free

Rotor blade

One to eight ESR x25 sensors per rotor blade
Measurement direction along the rotor blade axis
Several fieldbus gateways for sensor signal conversion

Machine frame

Several ESR x25 sensors for strain measurement at the machine frame possible
Several fieldbus gateways for sensor signal conversion

Tower and foundation

Several ESR x25 sensors for strain measurement in the tower possible
Measurement direction along longitudinal axis of the tower
Several fieldbus gateways for sensor signal conversion

STRAIN MEASURMENT FOR …

CONTROL OPTIMIZA TION

Direct integration into wind turbine control system
System components incl. strain sensors ESR x25 made for continuous operation
Optionally provided software increases availability and reduces uncertainties
Turbine control support for system calibration procedures

MEASUREMENT CAMPAIGNS

Direct signal recording using data loggers
Ideal for load measurement campaigns based on IEC 61400-13
Installation 50% faster than conventional strain measurement systems
Re-useable system components incl. strain sensors ESR x25

MEASUREMENT IN TOWER BOTTOM

Comparison to strain gauge signals
Good match between strain gauge and ESR
No offset-drift at high deformation levels
Better signal-to-noise ratio through larger measuring distance

Measurement reports and certificates

Every ESR sensor is tested for proper functioning and measured for precision
Based on article and serial number a quality inspection certificate is supplied with each sensor
Optional: On demand a DAkkS calibration according to DIN EN ISO/IEC 17025 can be performed