SeaTwirl is a floating vertical axis wind turbine placed offshore. The vertical axis wind turbine is mounted on an underwater structure that reaches deep beneath the water’s surface. This underwater structure contains a buoyancy part and, at its lowest point, a weight part. This makes the structure stable. The full body from the wind turbine in the top to the lowest underwater weight is rotating as one piece and all its weight is carried up by the water.
To translate the kinetic energy into electrical energy, a generator is placed around the rotating tower. The generator is placed above the sea level and is held in place using anchoring to the bottom of the sea. Since SeaTwirl uses an anchoring method, it may be placed on deep waters.
Emotron Active Front End (AFE) regenerative drives offer the option of feeding energy back to the mains, and are rated for four quadrant operation with 100% power in both directions.
The AFE units are delivered as complete IP54 classified solutions and are based on Emotron standard AC drives. Emotron AFE produces typically less than 5% THDi compared to 30-50% in conventional drives, thereby fulfilling the IEEE-519 standard.
For the SeaTwirl project, a VFXR46-146 was mounted in an 800 mm wide cabinet with a HMI panel placed in the front door for faster and easier access. Modbus TCP/IP communication were used for data collection and monitoring of actual values. Using this technique gave SeaTwirl a reliable and cost-effective drive solution.