High voltage direct current (HVDC) transmission technology has begun to play a great role in power transmission industry over the last decade. However, short-circuit fault seriously threatens the safety of an HVDC network. In order to reduce the fault current level of an HVDC network, utilizing a superconducting fault current limiter (SFCL) was proposed by researchers and engineers worldwide. Recently, Guangdong Grid Company of China Southern Power Grid, Co. has led a project to develop a 160 kV/1 kA resistive type DC SFCL. As a middle-step objective, a 160 kV/1 kA laboratory prototype has been developed. Due to a facility with an adequate capacity for testing such DC equipment is practically inaccessible, the current limiting performance of the prototype cannot be tested with a straightforward current limiting experiment. In practice, effectual alternative methods have to be adopted. Since the AC half-wave impact method requires less equipment and cost than the DC impact method, we took on an AC half wave impact current method to evaluate the current limiting function of the prototype alternatively. In this paper, we report the procedures and results of these tests.

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High Temperature Superconducting (HTS) cables have numerous advantages in comparison with conventional power cables, such as high power density and low power losses, so they have great potential in enhancing the transmission capacity and improving the quality of power grids. In this work, we studied various cases to evaluate the feasibility of replacing conventional cables with HTS cables in metropolitan distribution networks. These cases represent three principal strategies. The first, HTS cables are applied at the same or lower voltage levels with the same transmission capacity, named as "equal capacity replacement". The second, considering the increasing power demands we demonstrate how HTS cables can benefit the power grids with expanded capacity (expanded capacity replacement). The third, we consider the case of unequal routes from the perspective of saving land resources (unequal routing replacement). In this paper, we introduce the methods and results of this study and give some preliminary conclusive remarks.

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