Home > Products > T&D Systems > Protection & Control Systems > History of P&C Systems
| 2005 | Fully numerical line differential protection for communication either by pilot wire or direct fibre optic link (GRL150) |
|---|---|
| 2004 | Distance relay (GRZ100) with IEC61850, a prototype demonstrated at CIGRE in Paris |
| 2003 | Distance relay (GRZ100) with integrated communication |
| 2002 | Distribution system protection (GRD100 series) |
| 2001 | World's first commercial GPS synchronised line differential relay (GRL100) installed on 400kV network in the UK. |
| 2000 | Network solution equipment for the system monitoring and measurement |
| 1999 | Compact & high performance numerical relay (GR-series) Substation automation system (GSC1000) |
| 1993 | Toshiba's third generation numerical relay (D3) |
| 1989 | World's first microprocessor-based substation automation system applied to 275kV substation |
| 1986 | Toshiba's second generation numerical relay (D2)Since then, numerical relays have been developed to satisfy all types of application. |
| 1985 | Microprocessor-based transformer protection relay |
| 1984 | World's first microprocessor-based power system stabilizing relay applied to TEPCO's metropolitan underground cable network |
| 1980 | World's first microprocessor-based PCM current differential relay applied to 275kV line (D1)World's first microprocessor-based distance relay applied to 66kV line |
| 1977 | World's first FM current differential relay applied to 275kV line |
| 1969 | World's first static phase comparison relay having automatic testing and self diagnosis |
| 1968 | World's first preventive fault extension protection system |
| 1960 | Multi phase autoreclosing with segregated phase comparison relay applied to 275kV |
| 1959 | Static busbar protection relay |
| 1956 | Phase comparison relay applied to 275kV line |
| 1954 | Transformer protection relay based on percentage current differential |
| 1952 | Pilot wire relay applied to 275kV line |
| 1951 | Directional comparison relay |
| 1950 | Distance relay |
| 1939 | Induction cup type directional relay |
| 1920 | Induction disk type overcurrent relay |
| 1907 | Plunger type overcurrent relay |
