Method and apparatus for differential protection of protection section, relay protection device

A relay protection device capable of providing differential protection for a protection section of a power system, the protection section comprises a first current transformer and a second current transformer connected at each end of the protection section, the relay protection device comprises:

• a current obtaining module for continuously obtaining a first secondary current value of the first current transformer and a second secondary current value of the second current transformer;
• a determination module for determining a differential current value and a braking current value based on the first secondary current value and the second secondary current value;
• and
• a judgment module for opening a judgment window in response to an occurrence of a fault in the power system, and in response to the differential current value and the braking current value satisfying an in-section fault condition during the judgment window, judging the fault as an in-section fault, otherwise judging the fault as a fault to be determined;
• wherein the in-section fault condition is that the absolute value of the differential current value is consistently greater than the absolute value of the braking current value, and the absolute value of the differential current value is monotonically increasing.

An apparatus for differential protection of a protection section of a power system, comprising:

• at least one processor;
• and
• at least one memory in which is stored an executable program which, when the executable program is executed by the at least one processor, performs a method for a protection section of a power system, a first current transformer and a second current transformer are respectively connected to each end of the protection section, the method comprises:
• continuously obtaining a first secondary current value of the first current transformer and a second secondary current value of the second current transformer;
• determining a differential current value and a braking current value based on the first secondary current value and the second secondary current value;
• and
• opening a judgment window in response to an occurrence of a fault in the power system, in response to the differential current value and the braking current value satisfying an in-section fault condition during the judgment window, judging the fault as an in-section fault, otherwise judging the fault as a fault to be determined,
• wherein the in-section fault condition is that the absolute value of the differential current value is consistently greater than the absolute value of the braking current value, and the absolute value of the differential current value is monotonically increasing.