Effect of Transverse Compressive Loading on the Quench Characteristics of Epoxy-Impregnated REBCO-Coated Conductor

Abstract

REBCO-coated conductor is widely used in various HTS power applications. The HTS coils for power applications are generally impregnated with epoxy resin to enhance their mechanical stability, and the coil conductors would be subjected to transverse compressive loading in these applications. Although the effect of various operating conditions on the quench characteristics of REBCO-coated conductor have been investigated, the effects of compressive stress on quench characteristics of epoxy-impregnated REBCO-coated conductor has rarely been reported. This study examined the effects of transverse compressive loading on the minimum quench energy (MQE) and normal zone propagation velocities (NZPV) of epoxy-impregnated REBCO-coated conductor. The critical current of the conductor shows little degradation when transverse compressive stress is applied up to 80 MPa. Under the same compressive stress, the MQE decreases but the NZPV increases with the transport current. For fixed transport current, compressive stress increases the thermal contact conductance between conductor and epoxy which allows the heater energy of the conductor dissipating faster towards the surrounding epoxy, resulting in the increase of MQE and decrease of NZPV when increasing transverse compressive stress. The results indicate that higher compressive stress is helpful to decrease the quench damage of the conductor.