News From Japan

Electrical power networks are part of the basic infrastructure of today¿s society. Therefore, when a fault occurs in a power network, a prompt recovery is essential. For underground cable lines, fault point location systems, in which a surge current due to the fault is detected, are widely used. In conventional systems, detection of electro-magnetic induction induced by a surge current is widely used as a sensing method. However, sensing devices utilizing this method are easily affected by external electro-magnetic noise, and thus stable and reliable operation of the fault detection systems is compromised. Furthermore, conventional current detecting systems have several disadvantages, e.g., large sensing heads and heavy signal transmission lines, and thus they lack flexibility and portability.