FIELD: electricity.
SUBSTANCE: invention relates to the method of short-circuit identification (16) in a line (10) of multiphase electrical power supply network with an earthed neutral. Essence: the current and voltage sampling values are accepted and the signal of failure is generated, if the failure assessment made by the electrical protection device (12a) indicates the short-circuit (16), present in the line (10). Instantaneous reference voltage values from accepted before the occurrence of short-circuit (16) instantaneous current and voltage sampling values, and instantaneous comparative voltage values from accepted before the occurrence of short-circuit (16) instantaneous current and voltage sampling values from accepted during the short-circuit (16) instantaneous current and voltage sampling values are calculated. Then the rectified value of the reference voltage from the following one after another instantaneous reference voltage values and rectified comparative voltage value from the following one after another instantaneous comparative voltage values are calculated. The failure signal is generated, if the difference between the rectified comparative voltage value and rectified reference voltage value exceeds the operation threshold value.
EFFECT: improved operation speed.
12 cl, 9 dwg
