Rotating asynchronous converter and a generator device

A rotating asynchronous converter for connection of AC networks with equal or different frequencies, wherein the converter comprises a first stator connected to a first AC network with a first frequency f1, and a second stator connected to a second AC network with a second frequency f2, wherein the converter comprises a rotor which rotates in dependence of the first and second frequencies f1, f2, and wherein at least one of said stators comprises at least one winding, including at least one current-carrying conductor, and an insulating system including

• a first semiconducting layer surrounding the conductor and being in contact therewith;
• a solid insulation layer surrounding the first layer;
• a second semiconductor layer surrounding the insulating layer;
• said insulating system forming an equipotential surface surrounding the conductor, and wherein said first and second semiconducting layers and the solid insulation layer have substantially equal thermal expansion coefficients.