Control System for Start-up and Shut-down of a Floating Vertical Axis Wind Turbine

A baseline control system for the Deepwind floating vertical axis wind turbine (VAWT) concept is analysed with em- phasis on start-up and shut-down schemes. The turbine concept includes a rotating spar with a 2-bladed rotor at the top and a submerged generator at the bottom, anchored to the seabed with mooring lines attached to the stator-side of the generator. The controller is a typical PI control system with a notch filter to damp 2p torque variations. Start-up and shut-down logic is presented in detail, with simulation results demonstrating smooth start-up and shut-down at high wind speeds without severe spikes in generator torque.