A FAULT CURRENT LIMITER

摘要

A three phase fault current Iimiter (FCL 6) has three spaced apart input terminals (10) for electrically connecting to respective terminals (5) of a transformer (2). Three output terminals (1 1 ) electrically connect FCL (6) with a load circuit (9) which draws load current ILOAD- FCL (6) includes two longitudinally spaced apart generally circular High Temperature Superconducting (HTS) DC coils (12) which have central generally cylindrical cavities. FCL (6) also includes a longitudinally extending magnetically saturable core (14) which has six like coextensive parallel and elongate posts (15). Each post (15) includes a first longitudinal portion (16) and, a second longitudinal portion (17) and a third longitudinal portion (18) extending longitudinally oppositely away from the first portion (16). Each second portion (17) and third portion (18) is received within one of the central cavities. Three copper-based insulated AC coils (20, 21 and 22) are each wound about respective first portions (16) for carrying load current ILOAD between input terminals (10) to respective output terminals (1 1 ). DC coils (12) magnetically bias the core (14) such that, in response to one or more characteristics of the load current ILOAD, the AC coils (20, 21 and 22) move from a low impedance state to a high impedance state.