Power lead for electrically connecting a superconducting coil to a power supply

A power lead electrically connecting a superconducting coil with an AC power supply, comprising:

• a first and second thermoelectric cooling means, each of said means including a pair of an N-type thermoelectric member and a P-type thermoelectric member;
• a first switch provided between one terminal of said AC power supply and said first thermoelectric cooling means;
• and
• a second switch provided between an other terminal of said AC power supply and said second thermoelectric cooling means;
• said superconducting coil being accommodated on a side facing one end of said first and second thermoelectric cooling means, said side being in an opposite direction against a side facing said AC power supply;
• wherein said first and second switches are changed in response in a power line frequency so that said N-type thermoelectric members and said p-type thermoelectric members of said first and second thermoelectric cooling means are arranged in an upper stream and a down stream respectively to drive said superconducting coil in an alternating current mode.

A power lead electrically connecting a superconducting coil with a first power supply, comprising:

• a first and second thermoelectric cooling means, each of said means including a pair of an N-type thermoelectric member and a P-type thermoelectric member;
• said N-type and P-type thermoelectric members of said first and second thermoelectric cooling means being electrically connected in common on one end facing said superconducting coil, said ends being electrically connected to associated ends of said superconducting coil;
• second power supplies connected to said first and second thermoelectric cooling means on a side of facing said first power supply to provide a positive voltage to said N-type thermoelectric member against said P-type thermoelectric member;
• and
• a means for monitoring currents flowing through said superconducting coil and said first and second thermoelectric cooling means to control said first and second power supplies for providing an optimum cooling.

A power lead electrically connecting a superconducting coil with a first power supply, comprising:

• a plurality of thermoelectric cooling means, each of said means including at least a pair of an N-type thermoelectric member and a P-type thermoelectric member;
• and
• a plurality of second power supplies;
• said pair of said N-type and P-type thermoelectric members of said plurality of thermoelectric cooling means being connected in common at one end to be connected to said superconducting coil for magnetization, and on other end opposite to said superconducting coil being connected to said first and/or second power power supplies through a group of switches;
• wherein during a time period for exciting said superconducting coil for magnetization, said N-type and P-type thermoelectric members are connected in parallel to feed a current to said superconducting coil at least from said first power supply and during a time period when said superconducting coil is not excited, said group of switches are switched to change connections to configure plurality of thermoelectric cooling means in series for reducing a current flowing said second power supply.

A power lead electrically connecting a superconducting coil with a power supply, comprising:

• a thermoelectric cooling means including at least an N-type thermoelectric member and a P-type thermoelectric member being connected to a positive side and a negative side of said power supply respectively;
• conductors, made up of meal of a semiconductor, one end of said conductors being connected to said thermoelectric cooling means;
• a high temperature superconducting member accommodated between said conductor and said superconducting coil;
• and
• a switch for electrically connecting said conductors, said conductors being connected to said N-type and P-type thermoelectric members;
• wherein said switch is controlled to be open when exciting said superconducting coil for magnetization and closed when said superconducting coil being not excited.