Applied Measurements Ltd (United Kingdom) - AIM – Precisely & Quickly Monitor Power Take-Off Torque on A Wave Energy Converter.

Challenge:

As part of a project funded by Wave Energy Scotland, 4c Engineering needed to test various configurations of the SeaPower Platform, a Wave Energy Converter (WEC), to determine the effects on power capture. To do this they needed a reliable and accurate way of measuring power take-off (PTO) torque, forces, positions and pressures of the waves on the SeaPower Platform.

Why? Establishing the most efficient design with the highest wave power generation, will make it a more cost-efficient form of wave energy.

The SeaPower Platform extracts energy from deep water ocean waves by reacting to long prevailing wavelengths in high resource sites.

Solution – Applied Measurements Accurate DTD-P Parallel Shaft Reaction Torque Transducer:

“We chose the DTD-P torque transducer for its high accuracy and compact size which we needed for tank testing the SeaPower Platform,” explains Andy Hall, Director at 4c Engineering.

• Designed for In-Line Static or Semi-Rotary Torque Measurement
• Capacities: 0-10Nm to 0-10kNm
• High Accuracy – Ideal for Calibration, Development and Testing Applications
• Accuracy: <±0.15% / Full Scale Output
• Customised Capacities, Shaft and Configuration Options Available
• IP67 Waterproof and IP68 Fully Submersible Versions Available

Complete Torque Monitoring System:

Applied Measurements Ltd provided 4c Engineering with a DTD-P 100Nm parallel shaft torque sensor fitted with an ICA4H miniature load cell amplifier, calibrated to UKAS traceable standards and sealed to IP68 to allow complete submersion.  This complete torque measuring system enabled their engineers to reliably and accurately monitor the torque applied by the WEC as it responded to waves in the test tank.

Save on Installation Time:

The DTD-P torque transducer has keyed parallel shaft connections for in-line static or semi-rotary torque measurement in capacities from 0-10Nm up to 0-10kNm (custom capacities readily available).  This version was fitted with a flying lead, however versions with an integral bayonet lock military connector are also available which promise simple and easy connection.

Guaranteed High Accuracy:

The DTD-P torque transducer is highly accurate to better than ±0.15% (typically ±0.05%) of the full scale output, making it ideal for this high precision development and testing application.  Additional applications include the testing of electrical motors, hydraulic pumps, automotive transmissions, steering systems and aircraft actuators.

Need a Specific Design?

The DTD-P torque transducer can be customised with bespoke shaft, configuration options and capacities (to 50kNm+) specific to your application.  For 4c Engineering we customised the design of the DTD-P torque transducer to IP68 submersible for continuous use underwater to 1m, which was essential for use in the wave test tank.

High Stability, Fast Response, ICA4H Miniature Load Cell Amplifier:

“The high speed, reliability and clean output of the ICA4H miniature amplifier enabled the data to be analysed immediately after each test.” says Andy Hall of 4c Engineering.

• Very Compact 19mm Diameter
• Low Current Consumption
• High Speed 1kHz Bandwidth (max.)
• 4-20mA (3-wire) Output (10 to 30Vdc supply)

Very Compact:

To deliver a conditioned load cell output signal we supplied the DTD-P torque transducer with an ICA4H high performance miniature load cell amplifier.  The ICA miniature load cell amplifiers are very compact at only 19mm in diameter allowing them to fit inside the body of most load cells.  In this application the ICA4H was supplied in a gel filled IP68 immersion protected compact enclosure (see image above) along with 10 metres of cable making it suitable for this underwater application.

With High Speed Response:

The engineers at 4c Engineering needed to have a quick and reliable way to process the power take-off torque data from the tests, to determine the power capture and effects of the control settings before running the next test.  The ICA4H miniature load cell amplifier was chosen not only for its high stability and compact size but also for its 1000Hz fast response.

Products Used:

• Customised DTD-P Parallel Shaft Reaction Torque Transducer
• ICA4H Miniature Load Cell Amplifier + In-Line Enclosure

References:

Seapower Ltd. 2018. Technology. [ONLINE] Available at: http://www.seapower.ie/our-technology/. [Accessed 15 May 2018].

4c Engineering. 2018. Sea Power Ltd. [ONLINE] Available at: http://www.4cengineering.co.uk/case-studies/sea-power-numerical-modelling/. [Accessed 15 May 2018].