FIELD: electricity.
SUBSTANCE: from the moment the first short-circuit current surge appears on buses of the main power supply source, simultaneously they start counting time of delay for protection actuation in sectionalising (SCB) and head (HCB) circuit breakers of the line of the main source of power supply, at the same time they monitor the moment of short circuit current disconnection, and if at the moment of SCB delay time ending the short circuit current does not switch off, but it switched off at the moment of HCB delay time ending, the conclusion is made on failure of SCB disconnection and HCB disconnection, from the moment of disconnection of the first short circuit current surge they start counting time of delay for connection of a circuit breaker of a network station of ALT (NSCB ALT), and at the moment of count stop at the buses of the reserve power supply source transformer they monitor appearance of the second surge of short circuit current, and if it appears, then the conclusion is made on connection of this circuit breaker to short circuit, from the moment the second surge of short circuit current appears, they simultaneously start counting time of delay of protection actuation with acceleration of NSCB ALT and time of delay of protection actuation of SCB in the line of the reserve power supply source, and if the second surge of short circuit current switches off at the moment of ending of not the first specified time, but the second time, the conclusion is made on the failure of NSCB ALT disconnection and disconnection of SCB in the line of the reserve source of supply.
EFFECT: expansion of functional capabilities.
