Many long term installations, such as wind turbine or other renewable energy generators, or marine propulsion systems, can over time develop problems caused by excessive static or dynamic in-service loading. Retrofitting typical instrumentation to troubleshoot problems would often require expensive and time-consuming modifications.
Transmission Dynamics has developed an all-in-one, quick-deployment package based on our standard Radio Microlog, which can be retrofitted to in-service wind turbine shafts for periods of up to several months, to monitor the most significant (highest positive and highest negative) torque events experienced during routine operation. The package includes magnetic mounting clamps to fit to any shaft diameter (larger than 300 mm) and integral battery supply, allowing unattended torque data collection. Installation can be as simple as clamping the instrument, and adhering one or two pre-wired gauges to the shaft with rapid setting epoxy.
The equipment is also suitable for other applications, such as other renewable energy generators or marine propulsion systems.
From our considerable experience gained from in-service load measurements, we have confirmed that the majority of in-service wind turbines experience occasional unexpected transient torque overloads, including overloads in the negative direction, which were significantly outside the gearbox manufacturer's specifications. Additionally, occasional events cause a rapid torque reversal (from high positive to negative, and vica versa), which can result in exceedance of the permissable contact stresses in the rolling element bearings. Sudden load reversals can result in instantaneous loading of the misaligned rollers in the unloaded zone, and such events may explain frequent bearing failures which occur under loads well within the manufacturer's specification. Most of these events can typically occur during mode change, deployment of the aerotip or caliper brake systems, or engagement onto the grid.
The device, equipped with high-capacity batteries, measures 120x100x56 mm. Microlog has a configurable sampling rate of up to 4,000 Hz at true 16-bit per channel, and can log and evaluate real time torque and bending loads simultaneously on two channels. The system also functions as a powerful telemetry system with reliable signal transfer from rotating machinery, exceptionally low noise and high reliability of performance. High immunity and exceptional rejection of interference make this device an ideal tool in the most critical data acquisition tasks.
On most occasions, our customers are able to communicate with the device installed inside the nacelle (up to a height of 80 m) with our transceiver at ground level, allowing data to be downloaded without stopping or climbing the turbine. Many of our customers choose to install our stationary GPRS transceiver in the turbine, powered from the mains supply (and where mobile/GPRS signal is available), allowing remote data download via the internet, without having to travel on-site.
Click here to view our information sheet (PDF) for our Magnetically attachable, quick-deployment data logger system.
Click here to view our technical report, detailing torque reversals and consequent roller bearing damage witnessed on a customer's site
For a full technical specification on the system, please see our Radio Microlog product page, upon which this product is based.