FIELD: electricity.
SUBSTANCE: short circuit (SC) current is registered at the input of supply transformer (ST) and in outgoing lines. SC current is registered at the ST input between input breaker and ALT breaker. SC current is registered at the same moment of time in outgoing lines. Voltage is monitored in section of ST buses, and if SC current is both available at ST input and in one of outgoing lines, and after its disconnection by protection there is no voltage on section of ST buses, conclusion is made that short circuit occurred in outgoing line and its breaker failed. In this case ALT prohibition signal is sent. Additionally SC current is registered at the ST input between input breaker and ALT breaker. SC current is registered at the same moment of time in outgoing lines. Position of short-circuited outgoing line breaker is monitored. Voltage is monitored in section of ST buses, and if SC current is both available at ST input and in one of outgoing lines, and after its disconnection the breaker of this line remained in connected position, besides there is no voltage on section of ST buses, conclusion is made that short circuit occurred in outgoing line and its breaker failed, in this case ALT prohibition signal is sent.
EFFECT: improved reliability of method.
2 dwg
