FIELD: electricity.
SUBSTANCE: invention can be applied to electrical engineering. According to method of identifying direction, wherein malfunction in three-phase electric network (12a) of medium voltage power supply occurs relative to measurement point (19a, 19b) in medium voltage power supply network (12a), electric protective device (18a, 18b) control device (37) for detection of fault direction are used both measured current values, relating to phase conductor, and measured voltage values, relating to phase conductor. Measured current values are recorded at measurement point (19a, 19b) in medium voltage power supply network (12a). In order that direction where malfunction occurs relative to measurement point (19a, 19b) was easy and thereby efficiently recognized, it is proposed, that measured voltage values were recorded on the side of low-voltage transformer (13), connecting medium voltage power supply network (12a) with low-voltage power supply network. Invention also relates to correspondingly made electric protective device (18a, 18b).
EFFECT: higher reliability and simple determination of fault direction.
9 cl, 2 dwg
