Method and apparatus for a superconducting direct current generator driven by a wind turbine

A direct current (DC) generator for a wind turbine mounted on a tower comprising:

• an annular armature driven directly by a wind turbine and rotating with a rotating component of the wind turbine;
• a non-rotating annular field winding coaxial to the armature and separated by an annular gap from the armature, wherein the field winding includes superconducting coil magnets;
• a non-rotating support for the field winding;
• a fixed support coupling the non-rotating support for the field winding to a base fixed to an upper region of the wind turbine, wherein the fixed support is connected at one end region to the non-rotating support and is connected at an opposite end region to the base, and wherein the fixed support suspends the field winding over the base;
• and
• a commutator assembly configured to transfer DC current generated by the rotating armature to a power conversion system, the commutator assembly comprising a rotating first portion disposed proximate the annular armature and configured to rotate therewith and a stationary second portion coupled to a stationary platform and configured to receive direct current generated by the rotating armature through the at least two commutator segments.

A method for generating a direct current (DC) for a wind turbine comprising:

• generating a magnetic field in a non-rotating annular field winding in a DC generator, wherein the field winding includes superconducting coil magnets and the DC generator is mounted in an upper section of a tower for a wind turbine;
• applying torque from the wind turbine to rotate an armature of the DC generator, wherein the armature is coaxial and electromagnetically coupled to the superconducting field winding;
• generating electrical current in the armature by the rotation of the armature around the stationary field winding;
• transferring the direct current from the rotating armature to a power conversion system via a commutating assembly wherein a rotating first portion is disposed proximate the annular armature and configured to rotate therewith, the rotating first portion configured in electrical contact with the rotating armature and a stationary second portion is coupled to a stationary platform and configured to receive energy generated by the rotating first portion;
• cooling the superconducting coil magnets to a superconducting condition using a cooling liquid that is at least partially vaporized as it cools the coils;
• and
• condensing the vaporized cooling liquid in a re-condenser elevated above the DC generator, wherein the condensed cooling liquid flows by gravity to the superconducting coil magnets.