Introduction to the History of Selective Protection

Author: Walter Schossig, Germany

The Introduction of Electronics

In 1934 Wiederöe proposed the use of electronics in protection devices. Four years later Maret proposed the use of electronic tubes instead of electromechanical relays for line differential protection. The introduction of analogue measuring techniques began in 1965 and by 1967 Morrison had analyzed the use of computers for grid and network simulation. Two years later Rockefeller published his Masters thesis "Computer Protection" and from hence digital protection technology was to become a reality.

In 1977 the 110-kV/20-kV substation Bad Kissingen substation in Germany became the first substation in Europe that was completely protected by digital protection. This substation had a computer to implement the protection processes and for the real-time logging of events.

Figure 13 Process Computer in the Substation Bad Kissingen (SIEMENS)

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