The concept, developed for 3MW-plus machines, features a beefed up slip-ring construction to boost reliability and cut maintenance costs.

"We believe DFIGs are long-runners as they are a proven technology - even as onshore turbines continue to get bigger," ABB head of wind power Alfredo Parres tells Recharge.

"We felt the industry needed a new design that fits with this size of turbine - which we see as the main play for onshore markets."

Testing