FIELD: electricity.
SUBSTANCE: invention is referred to the relay protection of power plants and automated substation systems, in particular, to forecasting and detecting the saturation of the current transformer at the sympathetic inrush current. The method for forecasting the saturation of the current transformer contains the following stages, whereat the first current from the first current transformer is detected at a high-voltage side of the transformer and the second current from the second current transformer is detected at a low-voltage side of the transformer; the first fundamental vector, the first DC component and the first total root-mean square value of the first current are computed and the second fundamental vector, the second DC component and the second total root-mean square value of the second current are computed; a signal is generated for forecasting the saturation of the current transformer in compliance with the first fundamental vector, the first DC component and the first total root-mean square value, the second fundamental vector, the second DC component and the second total root-mean square value.
EFFECT: saturation of the current transformer may be forecasted effectively before the actuation of the transformer differential protection; thus the incorrect operation of the transformer differential protection may be prevented.
11 cl, 10 dwg
