What is superconducting magnetic energy storage (SMES)?

(1) When the short is opened, the stored energy is transferred in part or totally to a load by lowering the current of the coil via negative voltage (positive voltage charges the magnet). The Superconducting Magnetic Energy Storage (SMES) is thus a current source [2, 3]. It is the “dual” of a capacitor, which is a voltage source.

How to design a superconducting system?

The first step is to design a system so that the volume density of stored energy is maximum. A configuration for which the magnetic field inside the system is at all points as close as possible to its maximum value is then required. This value will be determined by the currents circulating in the superconducting materials.

What is a large-scale superconductivity magnet?

Keywords: SMES, storage devices, large-scale superconductivity, magnet. Superconducting magnet with shorted input terminals stores energy in the magnetic flux density (B) created by the flow of persistent direct current: the current remains constant due to the absence of resistance in the superconductor.

What is the main objective of a energy storage system?

The general objective, apart from the minimization of the production cost and the maximization of the discharge speed etc., is to abase the losses over the charges/discharges of the system. The first step is to design a system so that the volume density of stored energy is maximum.

How to design a superconducting coil system?

When designing an SMES system, the superconducting coil structure must have the best performance depending on the application for which the SMES will be used. The general objective, apart from the minimization of the production cost and the maximization of the discharge speed etc., is to abase the losses over the charges/discharges of the system.

What is the value of stored energy per unit mass?

Assuming a reasonable working stress of 100 MPa, the virial theorem gives for a magnet with steel structure the value of stored energy per unit mass (mass specific energy) of 12.5 kJ/kg (3.5 Wh/kg). The CMS (Compact Muon Solenoid) magnet of the LHC collider almost reaches this value for its cold mass (2.6 GJ/225 tons or 11 kJ/kg).