EMS ELONGATION MEASUREMENT SYSTEM Strain measurement system for wind turbines optimizing the control & condition monitoring
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EMS ELONGATION MEASUREMENT SYSTEM 1 Rotor blade Rotor blades are the point of origin for generating the power and major system loads in a wind turbine. Special sensors in the rotor blades, particularly those located in the root position of each blade, are used to measure these individual loads. If required, sensors can also be positioned at up to 50 % of the blade length. The data collected by these sensors can be used for additional condition monitoring, as validation between calculated and precise measurement data and for implementing new control concepts. For more efficiency and yield. 2 Machine frame The machine frame holds the main components (e.g. generator, gearbox) inside the wind turbine and serves as the link between rotor and tower. Wind turbine operation causes dynamic interactions among the individual components, which in turn subjects the machine frame to many complex loads. Sensor solutions used for this purpose are designed to measure the relative movement of the components in relation to each other as well as indicators for component wear and tear. The knowledge gained from these data enables adaptive WT control for load optimization. Costly downtimes can be reduced to a minimum. 3 Tower and foundation The trend toward larger rotor diameters and higher hub heights also cause an increase of the load on the tower and foundation of wind turbines. At the same time, these components are major cost factors and represent an ever growing logistical challenge. A sensorbased, optimized WT control system can significantly reduce the loads in a wind turbine. This results in a noticeable reduction in component size and material cost.
EMS ELONGATION MEASUREMENT SYSTEM Up to 50 % blade length VRG Blade root VRG VRG PDB VRG VRG VRG Tower top VRG Tower bottom VRG
1 Installation and position in rotor blade 2 to 8 ESR x25 sensors per rotor blade Installed in the radial section of rotor blade root, preferably on the spar caps of the pressure and suction side and the leading and trailing edge Measurement direction along the rotor blade axis One or two fieldbus gateways per rotor blade for the connection of the sensors 2 Installation and position in tower 4 x ESR x25 sensors for each tower measuring position (tower head/tower bottom) Not to be installed in any area strongly influenced by geometry changes (e.g. a door). Ideally installed in the tower top and base and in the requisite intermediate sections Measurement direction along longitudinal axis of tower Each tower measuring position has a fieldbus gateway for connecting the sensors
ESR ELONGATION SENSOR ROTARY Picture: ESR 125 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. The sensor technology enables a high resolution of 0.025 με at a measuring range of +/- 5000 με. The integrated temperature sensor can be used for extended signal compensation during system operation. Additional information on the sensor electronics condition can also be read out. The EMS sensor is suitable for both short term measuring campaigns as well as for permanent operation as part of turbine control.
Products Robust strain sensor for sustained use in wind turbines ESR x25 The sensor is offered in different versions that enable highly accurate measurements possible under harsh ambient conditions and over long time spans. Thanks to the material-adjusted measurement section the sensor can be used for measurements on both glass fibre reinforced plastics (GFRP), carbon fibre reinforced plastics (CFRP) as well as on steel. This allows load measurements in the rotor blade, on the main frame and in the tower for the purpose of collecting information on the operating conditions of the wind turbine. Proven sensor technology Measuring section is adjusted to the material to be measured Force-free measurement and operation Quick and cost-efficient sensor installation Robust sensor design with treading protection High resolution with low signal noise Encoder exchange on site possible Upgradable for existing installations An ESR versions list can be accessed at our website www.ll-systems.com. Designs Measuring step 0.025 με (1 µε = 1 µm/m) Measuring range +/ 5000 µε Operating range 40 C +100 C Electronics EnDat 2.2, maximum sampling rate 100 khz, digital Electrical connection Mechanical connection M12, 8 Pin Adhesive installation and screw assembly, measuring section adaptable for temperature compensation Dimensions 337 x 77 x 82 mm (L x W x H) Weight about 0.65 kg Additional features Integrated temperature sensor, sensor condition information, electronic nameplate, OEM memory
ESR x25 sensor versions Optimally adapted to measurement task and installation Version Material* GFRP 8 x 10-6 K Austenitic steel 16 x 10-6 K CFRP 1 x 10-6 K Adhesive installation ESR 125 (version -01) ESR 125 (version -02) ESR 125 (version -03) Adhesive installation (screw-on adapter) ESR 225 - accessories Screw-on installation (screw-on adapter) ESR 325 - accessories ESR 225 (version -01) ESR 225 (version -02) ESR 225 (version -03) Adapter set for adhesive installation Template for adhesive installation ESR 325 (version -01) ESR 325 (version -02) ESR 325 (version -03) Adapter set for screw-on assembly Drill template for screw-on assembly *coefficient of thermal expansion of the ESR x25 measurement section ESR 125 ESR 225 ESR 325 With adhesive surfaces for direct bonding on the surface area to be measured. With screw-on adhesive surfaces to facilitate bonding on surface to be measured. For direct screwing on the surface area to be measured.
Measurement reports and certificates Quality inspection certificates and German Accreditation Body Calibration Certificates (DAkkS GmbH) Before delivery, every ESR x25 sensor is tested for proper functioning and measured for precision. A quality control certificate compliant to DIN 55 350-18-4.2.1 is supplied with each sensor. The certificate documents sensor accuracy by specifying the respective item and series number. The certificate also states the calibration standard and ensures compliance with national and international standards and traceability. Optional: DAkkS calibration according to DIN EN ISO/IEC 17025 can be performed on demand. The created calibration certificate documents a generally recognized traceability of the measuring device by an independent and neutral body. Example of quality inspection certificate:
EMS ELONGATION MEASUREMENT SYSTEM CRG 1:1 VRG 4:1 Compact and robust fieldbus gateways for sustained use in any environment The EMS measurement system include compact and robust fieldbus gateways. These gateways convert the sensor signal into a fieldbus signal and enable optimal and flexible adaptation to the given operating conditions. Up to four ESR x25 strain sensors can be connected to the VRG 4:1 fieldbus gateway. This version gives complete access to not only the strain measurement data, but also the sensor data: sensor temperature, sensor condition and electronic nameplate. If the VRG 4:1 is attached on the rotor blade side, it can be connected with a cable for power supply and data transfer. This greatly simplifies handling, especially when assembling or dissembling large components such as the rotor blade. A single ESR x25 strain sensor can be connected to the CRG 1:1 fieldbus gateway. The CRG 1:1 is a more cost-effective version for decentralized strain measurements with a low number of measuring points (e.g. on the machine frame).
Products Robust fieldbus gateways for flexible adjustment to match wind turbine design VRG 4:1 CRG 1:1 This robust gateway allows the connection of up to four ESR x25 strain sensors. It is designed for use in the rotor blades and tower of a wind turbine so that all measurement signals and data from the strain sensors can be collected, converted and transmitted. Applications that call for the analysis of highly dynamic movements are also possible since high sampling and transmission rates are supported. This gateway is also extremely robust and allows the connection of an ESR x25 strain sensor. This design features a large selection of fieldbus interfaces and connection options. Due to its wide temperature and operating range, the gateway can be installed in high-temperature areas. Designs VRG 4:1 CRG 1:1 Input signal sensor 4 x EnDat 2.2, digital 1 x EnDat 2.2, digital Output signal fieldbus CANopen, POWERLINK CANopen, PROFINET, PROFIBUS, Ethernet/IP Operating range 25 C +50 C 40 C +80 C Protection class IP 65 (IEC 60529) IP 65 (IEC 60529) Electronic connection EnDat 2.2: M12 EnDat 2.2: M12 fieldbus, fieldbus, voltage supply: M12 voltage supply: M12, cable gland Mechanical Connection adhesive installation, mounting rail, screw assembly wall assembly, Dimensions 150 x 185 x 70 mm (L x W x H) 90 x 29 x 125 mm (L x W x H) Weights 2.2 kg 0.4 kg Available information ESR x25: ESR x25: at the fieldbus position, temperature, position, electronic nameplate diagnostics, electronic nameplate Gateway: electronic nameplate Gateway: electronic nameplate
EMS ELONGATION MEASUREMENT SYSTEM PDB Electronic evaluation unit for data collection and analysis The robust PDB assessment unit can be a part of the EMS measuring system, which gathers all strain and diagnostics signals of the connected sensors by means of VRG fieldbus gateways. All raw values of the connected ESR sensors are thus available in an individual field bus node, enabling straightforward integration into the turbine control or measuring system. Depending on the selected software module, various functions for data analysis are alongside the raw values: reduction of measuring uncertainties, plausibilisation of measurement values, support of system calibration, evaluation of sensor-diagnostics and additional monitoring functions.
Products Robust evaluation unit for operation in wind turbines. PDB The compact process and data analysis box allows simple and quick integration of the entire measurement system into the the wind turbine. The evaluation unit can be installed directly at the wind turbine manufacturer or in existing installations. Synchronous data request for up to 36x sensors of type ESR x25 Up to 1 khz sensor sampling rate Integrated surge voltage protection module Quick readiness after switching on Power supply 24V DC, 2 A (for 3x VRG + 12x ESR x25) Software remote update capable Designs PDB Input signal Output signal Gateway: 3 x POWERLINK (of VRG 4:1 POWERLINK) Fieldbus: CANopen, Ethernet (other interfaces on request) Operating range -25 C +50 C Protection class IP 65 (IEC 60529) Electronic connection Mechanical connection 3 x POWERLINK, 3 x Power supply 1 x CANopen, 1 x Ethernet, 1 x Power supply All connections M12 Wall assembly Dimensions 260 x 540 x 130 mm (L x W x H) Weights about 10 kg Additional information Graphical user interface with calibration, Short-term data recording, user roles, Condition monitoring, diagnostics
Features and tests of the EMS strain measuring system Easy sensor alignment during installation Easy and secure mounting thanks to compact size and optimal design Simple and accurate alignment of sensor in the measuring direction with markings on the enclosure (notch and bead principle) Enclosed mounting aid (red) to support measurement arm positioning Intelligent sensor with diagnostic functions Absolut encoder Subsequent electronics U p 0V Absolut position value CLOCK CLOCK DATA DATA Operating parameters Operating status Parameters of the OEM Parameters of the sensor manufacturer for EnDat 2.2 The specially developed ASIC identifies the absolute position, temperature and warning and error messages and sends this information to subsequent electronics using the EnDat 2.2 protocol. Expansion is measured in the form of absolute positions spaced at 5 nm (0.025 με). The temperature refers to the ASIC temperature, which is linearly related to the ambient temperature. Warning and error messages are created when, for example, tolerances are exceeded or position values are incorrect.
Fatigue strength of sensor/rotor blade adhesive connection Load introduction Bending curve Load introduction Bending curve Tests: Fatigue test on test beam with up to ± 0.35% expansion Fatigue test on rotary blade with millions of load cycles in total (impact/pivoting direction) Results: The ESR 125 has a permanently fixed connection to the unit under test. Measurement drifts were not apparent. For comparison, installed strain gauge strips showed drifts and detachments from the surface. EMS lightning protection and grounding concept Tests: System test as per IEC 61400-24 in an accredited testing laboratory Induction test of lightning currents up to 20 ka/μs Results: The EMS strain measurement system with conceived grounding concept has successfully passed the test. The goal was to ensure proper function for installation in wind turbine blades.
Valid as of: 08 / 2017 LLS_EMS_08_17_0_EN Subject to changes and errors. LEINE LINDE SYSTEMS GmbH Am Sandtorkai 50, D-20457 Hamburg T +49-(0)40-3176758-0 F +49-(0)40-3176758-50 info@ll-systems.com www.ll-systems.com