Directional detection of a fault, in particular in a network with compensated or insulated neutral

• Main Authors: CUMUNEL, PASCAL, VERNEAU, GUILLAUME
• Format: Patent
• Language: English; French; German
• Published: 11.06.2014
• Subjects: CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION

The device has a first module (20) to provide a signal representative of homopolar voltage (V0) of a set of phases. A second module (40) provides a signal representative of derivative with respect to a time of homopolar current (I0). An activation unit activates the second module according to a detection signal (D) of occurrence of a ground fault in a multiphase medium voltage network. A location module (50) includes an evaluation unit to evaluate a phase shift between the homopolar voltage and the derivative of the homopolar current provided by the second module with respect to pi. Independent claims are also included for the following: (1) an indicator for indicating passage of ground fault (2) a relay for protecting a current line against ground fault (3) a method for directional detection of a ground fault in a multiphase medium voltage network (4) a method for protecting a current line during occurrence of a ground fault. Dans un réseau moyenne tension, notamment à neutre compensé et/ou à neutre isolé, la localisation d'un défaut monophasé selon l'invention repose sur : - une détection du défaut par la variation de la tension homopolaire (V 0 ) ; - une directionnalité déterminée sur le déphasage, notamment via l'angle ou le signe du produit, entre la dérivée du courant homopolaire (dI 0 /dt) et la tension homopolaire (V 0 ), en régime de défaut établi. Cette solution permet notamment une détection à faible échantillonnage.