Field coil protection for a SMES-supported all-purpose compensator

The use of superconducting coils to complete static volt ampere reactive (VAr) controllers provides an efficient protective system which detects quenches and saves the quenched coil from being damaged by thermal and electrical stresses. The authors deal with the peculiarities of designing the protective system of a 1.36-MJ experimental superconducting magnetic energy storage (SMES) system which will form part of a static compensator for multiple use in public power supply networks. A concept for selective use of the available protective devices which serves to achieve maximum energy recovery at a minimum thermal load of both field coils and cooling circuit in case of a quench is presented.<>