Inverness based marine renewable wave power specialists, Voith Hydro Wavegen recently completed installation of a 300kW commercial wave power plant.
Located in Mutriku in Northern Spain, the 300kW power plant is based upon Wavegen’s Nearshore Oscillating Water Column (OWC) technology, which employs Novotechnik RFC4800 series ‘touchless technology’ non contacting angle sensors.
Commissioned by Basque Energy Board (EVE), Wavegen’s Nearshore OWC was built into a new breakwater that was required to provide sea defence protection for the harbour at Mutriku. The civil structure consists of 16 integrated Wells turbines located above a large chamber with a submerged opening. The water level in the chamber rises and falls with the ocean.
Rising water compresses the chamber air, which is forced through the turbine generator. The falling water then sucks the air back through the turbine into the chamber. The Wells turbine is driven in the same direction irrespective of the air direction, generating electricity to the grid, enough to power 250 homes.
The RFC4800 angle sensor is used to provide position feedback for a large butterfly damper located between the chamber and the turbine. Driven by an electrical actuator, the damper is used to isolate the turbine for shutdown purposes as well as throttle the turbine airflow in extreme sea states.
Incorporating no moving parts, the completely non contacting design of the RFC4800 includes a magnetic position marker typically attached to the customer’s shaft that interacts with the sensor electronics, providing an analogue output proportional to angle position.
For the Wavegen application, the position sensor element is fixed to the turbine frame and the corresponding magnetic position marker is located directly on the end of the actuator shaft. With no bearings to wear and with each element IP69 sealed, high reliability and long working life is ensured, delivering an MTBF rating of 50000 hours for the electronics.
Novotechnik’s RFC4800 series angle sensors are used widely for extreme environment applications in agricultural and construction equipment as well as marine and automotive areas. Highly resilient to shock and vibration, the sensors are well suited to space restricted installations in moving vehicles, while the transmissive properties between magnet and sensor means that the operation can be enabled through non-magnetic barriers such as gearbox casings.
RFC4800 series angle sensors are available in a choice of three models for supply voltages of 5 VDC, 12 VDC or 12/24 VDC. Optional output formats include 0 – 10 VDC, 0.5 – 4.5 VDC, a ratiometric voltage based upon a pre-calibrated percentage of the input, and 4 – 20 mA. The standard electrical angle is 360 degrees but optional 30 to 360 degree specials can be supplied in addition to redundant output versions. IP67 environmental protected models are also available.
Novotechnik’s RFC4800 series angle sensors are available in Australia from Veederline