抄録
As for the protection relay, the innovations of relay technology was accomplished for 30 years leaping-ly. This relay technology innovations corresponded to the expansion of the electric power system are accomplished by the foresight.
In the composition of the protection relay equipment, it improved from the mobile contact-type relay of electromagnetic power to the solid state-type relay and moreover the technology was innovative at the digital-type relay by MPU. Then, the innovations of this hardware technology could be achieved by the establishment of the technology which make relay systems a high degree of the reliability by automatic and watching over equipment itself. On the other hand, because the innovations of this relay hardware technology could leave out the limitation of the protection relay function, it brought about the innovations of the software technology which protect bulk power systems to a high degree. The protection relay technology in Japan is the technology which have been most advanced in the world and is the technology which fitted in with the Japanese state of the affairs. As for this paper, it introduces the outline about the contents of the technology innovations and the big results of the technology innovations.
