METHOD AND PROTECTIVE DEVICE TO COMPUTE ELECTRIC NETWORK AS ROUTE SWITCHES IN LONG-DISTANCE NETWORK

摘要

FIELD: electricity.;SUBSTANCE: protective device for an electric network realises a method to balance measurement times of the first and second measurement of an electric value, where measurements are carried out at different ends of the electric network line and are transferred with their measurement times via the long-distance network. In the method the transfer time to transfer from a local (A) to a remote (B) end of the line and the time to receive from the remote (B) to the local end (A) of the line is determined on the basis of signals from inner clock oscillators. After the global timing for synchronisation of inner clock oscillators is lost, the drift of clock oscillators is identified between the inner clock oscillators. The time to measure the first and second measurements is balanced using transfer times during transfer and reception, as well as the clock oscillator drift. Sudden variation of the clock oscillator drift is identified to recognise switching of a route in the long-distance network, and the clock oscillator drift is corrected.;EFFECT: higher security of an electric network.;10 cl, 6 dwg