Method of protecting electric networks in case of oscillations by means of a blocking device, and blocking device for carrying out this method

摘要

for the protection of electrical networks with oscillation using a pendelsperre (p), the all the time, regardless of the impedanzwert,the temporal change in either the measured impedance or voltage multiplied by the cosine of the phase difference between current and voltage is monitored and analysed.the power supply (ir) and the spannungsanschluss (ur, us) is used.two parallelgeschaltete abtast and halteglieder (8,8 '), whose output signals in a device (9) to form a difference be subtracted.so that the downstream triggerschaltung (10) and a counter (11) at the output (12) of the pendelsperre (p), a logical signal only, makeif the triggerschaltung (10) within a predetermined time twice in a row, a logical signal.the electrical networks for security in pendelungen in cooperation with arbitrary kurzschlusschutzrelais sufficiently protected against initiation.