Performance of a Fault-Current Limiter with a New Type of Direct-Cooled Tubular Element

As one component of a fault-current limiter a high-speed acting type of high capacity current limiting fuse has been developed by using a direct forced cooling of the fusible tubular element. Although several coolants such as air, water, liquid nitrogen etc. were tested, water was recommended to be the best coolant. This kind of current limiter is available as not only an AC interrupter, but also a high-voltage DC interrupter for protection of thyristors in AC/DC substations and so on. The fault- current limiter consisting of multi-stage fuses could interrupt a prospective current of 7kA under a voltage of DC 40kV in l9ms after a fault occurrence.