METHOD OF DIFFERENTIAL RELAY PROTECTION, INCLUDING FOR TRANSIENT MODES ACCOMPANIED BY SATURATION OF MEASURING CURRENT TRANSFORMERS (VERSIONS) Russian patent published in 2024 - IPC H02H3/28 

FIELD: power engineering.

SUBSTANCE: inventions relate to power engineering, namely to methods of differential relay protection. Disclosed are relay protection methods that meet the requirements of selectivity and speed not only in the period of time after the beginning of the short circuit, when measuring current transformers (CT) operate without saturation, but also after this time interval, when measuring CTs are saturated, i.e. on the entire time interval of the emergency mode existence. For this purpose, in the time interval when the measuring CTs operate without saturation, the actuation characteristic is used (Fig. 2), and at the time interval when measuring CTs are saturated, change in the direction of currents or zeroing of the effective current value is monitored in the arms of the protected object.

EFFECT: ensuring correct operation of relay protection devices in transient modes accompanied by saturation of measuring current transformers.

5 cl, 17 dwg