Superconducting magnet apparatus and method of operating same
A superconducting magnet apparatus includes a plurality of superconducting magnet coil sections connected in series and housed within a cryogenically cooled, vacuum container. A power source generates a current. A first lead is electrically connected to the superconducting magnet coil sections. A second lead is enclosed entirely within the vacuum container. The second lead has a first section and a second section, and the first section is electrically connected to the power source. The second section is electrically connected to the first lead, and rigidly connected to a linear displacement device enclosed entirely within the vacuum container. The linear displacement device linearly displaces the second section relative to the first section, so that the first section contacts the second section thereby electrically connecting the first and second sections, or by creating a gap between the first section and second section thereby electrically disconnecting the first section from the second section.
1. A superconducting magnet apparatus comprising:
a plurality of superconducting magnet coil sections connected in series and housed within a cryogenically cooled, vacuum container;
a power source configured to generate a current;
a first lead electrically connected to the plurality of superconducting magnet coil sections;
a second lead enclosed entirely within the vacuum container, the second lead having a first section and a second section, the first section is electrically connected to the power source, the second section is electrically connected to the first lead, the second section is rigidly connected to a linear displacement device enclosed entirely within the vacuum container;
wherein the linear displacement device is configured to linearly displace the second section relative to the first section, so that the first section contacts the second section thereby electrically connecting the first section and the second section, or by creating a gap between the first section and the second section thereby electrically disconnecting the first section from the second section; and
wherein the second section is rigidly connected to the linear displacement device by an electrically insulating rigid member having thermal resistance.
2. The superconducting magnet apparatus of claim 1 , the linear displacement device comprising:
a piezoelectric linear displacement device or a pneumatic linear displacement device.
3. The superconducting magnet apparatus of claim 1 , wherein the linear displacement device is mounted to:
the vacuum container, or a thermal shield enclosed within the vacuum container.
4. The superconducting magnet apparatus of claim 1 , the plurality of superconducting magnet coil sections electrically connected to a plurality of series connected switches, and wherein each of the plurality of series connected switches are connected in parallel to one of the plurality of superconducting magnet coil sections.
5. The superconducting magnet apparatus of claim 3 , wherein the linear displacement device is controlled by a remote signal to selectively connect or disconnect the first section and the second section; and
wherein a ramp mode of operation is applied to the plurality of superconducting magnet coil sections when the first section contacts the second section, and a persistent mode of operation of the plurality of superconducting magnet coil sections is enabled when the first section is disconnected from the second section.
6. The superconducting magnet apparatus of claim 5 , wherein the plurality of superconducting magnet coil sections are electrically connected to a dump resistor located external to the vacuum container during a ramp-down mode.
7. A wind turbine comprising:
a tower;
a nacelle coupled to the tower;
a rotor comprising one or more blades, the rotor coupled to the nacelle; and
the superconducting magnet apparatus according to claim 1 housed within the nacelle, the superconducting magnet apparatus configured as a superconducting generator.
8. The wind turbine of claim 7 , the linear displacement device comprising:
a piezoelectric linear displacement device or a pneumatic linear displacement device.
9. The wind turbine of claim 7 , wherein the linear displacement device is mounted to:
the vacuum container, or a thermal shield enclosed within the vacuum container.
10. The wind turbine of claim 7 , the plurality of superconducting magnet coil sections electrically connected to a plurality of series connected switches, and wherein each of the plurality of series connected switches are connected in parallel to one of the plurality of superconducting magnet coil sections.
11. The wind turbine of claim 7 , wherein the linear displacement device is controlled by a remote signal to selectively connect or disconnect the first section and the second section; and
wherein a ramp mode of operation is applied to the plurality of superconducting magnet coil sections when the first section contacts the second section, and a persistent mode of operation of the plurality of superconducting magnet coil sections is enabled when the first section is disconnected from the second section.
12. The wind turbine of claim 11 , wherein the plurality of superconducting magnet coil sections are electrically connected to a dump resistor located external to the vacuum container during a ramp-down mode.