US 12,749,605 B2 · HTS magnet ramping to reduce screening currents

Abstract

A method of energizing or de-energizing a high temperature superconducting, HTS, coil, from an initial transport current to a final transport current. The HTS coil includes a plurality of turns of HTS material. A transport current is supplied to the HTS coil, starting at the initial transport current and varying over time to the final transport current. Cooling is applied to the HTS coil. An operating condition of the HTS coil is monitored, which is indicative of a ratio I/Ic of transport current, I, to critical current, Ic, of the HTS material in part of the HTS coil. The transport current applied to the coil and/or a net cooling applied to the coil are controlled in a feedback loop responsive to the operating condition, to maintain the operating condition in a desired range during energisation or de-energisation, such that the ratio I/Ic is maintained above a threshold (e.g. 0.7).

Claims20

Dependent claims

A method of energizing or de-energizing a high temperature superconducting, HTS, coil, from an initial transport current to a final transport current, the HTS coil comprising a plurality of turns of HTS material, the method comprising:

supplying a transport current to the HTS coil, the transport current starting at the initial transport current and varying over time to the final transport current;
applying cooling to the HTS coil;
monitoring an operating condition of the HTS coil, wherein the operating condition is indicative of a ratio I/Ic of the transport current, I, to a critical current, Ic, of the HTS material in at least a part of the HTS coil;
and
controlling one or both of the transport current applied to the HTS coil and a net cooling applied to the HTS coil in a feedback loop responsive to the operating condition, in order to maintain the operating condition in a desired range during energization or de-energization such that the indicated ratio I/Ic is maintained above a threshold ratio and below 1.

2 more elements

supplying a transport current to the HTS coil, the transport current starting at the initial transport current and varying over time to the final transport current;
monitoring a non-inductive component of the start to end voltage across the HTS coil;
applying cooling to the HTS coil to maintain the temperature of the HTS material at or below the zero field critical temperature of the HTS material;
and
controlling one or both of:
a rate of change of transport current;
or
a net cooling power applied to the HTS coil, where the net cooling power comprises the applied cooling and any applied heating of the HTS coil;
such that the non-inductive component of the start-to-end voltage across the HTS coil remains above a threshold at least until the transport current is equal to the final transport current.

6 more elements

A high temperature superconducting, HTS, magnet system, the HTS magnet system comprising:

an HTS coil comprising a plurality of turns of HTS material;
a power supply configured to supply a transport current to the HTS coil;
a cooling system configured to apply cooling to the HTS coil to maintain the temperature of the HTS material at or below the zero field critical temperature of the HTS material;
a voltage monitoring system configured to monitor the start-to-end voltage of the HTS coil;
a controller configured to control ramping of the HTS coil by:
causing the power supply to provide a transport current which starts at an initial transport current and varies over time to a final transport current;
and
determining the non-inductive component of the monitored start-to-end voltage of the HTS coil;
and
controlling one or both of:
a rate of change of transport current;
a net cooling power applied to the HTS coil, where the net cooling power comprises the cooling applied by the cooling system and any applied heating of the HTS coil;
such that the non-inductive component of the start-to-end voltage of the HTS coil remains above a threshold at least until the transport current is equal to the final transport current.

10 more elements

Dependencies are inferred from the claim text.

HTS magnet ramping to reduce screening currents

Life of this patent

HTS magnet ramping to reduce screening currents

Life of this patent

Abstract

Claims20