Design of a laminated-steel magnetic core for use in a HT-SMES

Since mid-1990s there was an impressive progress in manufacturing high-temperature superconducting (HTS) wires. However neither their prices nor properties still do not allow manufacturing efficient superconducting magnetic energy storage devices (SMES's). One of the ways to increase the stored energy of the coil and reduce the cost of SMES lies in the use of a magnetic core. We found that the so-called pot-core configuration simultaneously minimizes a volume of the core and magnetic field on the winding. Two laboratory models of an SMES's with a ferromagnetic core were constructed and tested. We also developed a method for analytical calculation of the optimal air gap of magnetic core necessary for maximizing stored energy, where we used power approximation of the B-H curve of the ferromagnetic material. This method is valid for the calculation of the dependence of the stored energy on the value of air gap of the core. One of these models was used as an example of stored energy calculations. The experimental stored energy values are close to the calculated values.