THREE-PHASE ELECTRICAL OVERVOLTAGE, NEUTRAL LINE BREAKAGE AND GROUND ANOMALY DAMPENING, ISOLATION AND PROTECTION SYSTEM, EXTERNAL ADDITIONAL MODULE AND METHOD

Abstract

The invention is a protection system comprising a measuring unit (7) that detects the minimum voltage, current and impedance parameters on lines L1, L2, L3 and N to provide protection against overvoltage, neutral line breakage, phase imbalance and ground anomalies in three-phase AC low-voltage electrical installations; a monitoring module (2) that determines the presence of an electrical anomaly based on the electrical parameters obtained from the measuring unit (7); a damping and isolation circuit (3) that limits the current and / or dampes the voltage pulse through at least one semiconductor switching element in case of detection of an electrical anomaly; a tripping and actuation mechanism (4) that enables the tripping of the main circuit breaker; a virtual neutral unit (8) that includes at least one dynamic impedance element to compensate for the potential deviation in the neutral line; and a stepped safety element chain (6) that activates if the main circuit breaker and / or the damping and isolation circuit fail to perform its tripping function.The impedance value of the virtual neutral unit (8) is dynamically changed by closed-loop or open-loop or matrix switching feedback depending on the instantaneous line impedance and / or voltage deviation determined by the measurement unit (7), and this dynamic impedance modulation is carried out during the transition period between the opening of the main circuit breaker and the completion of the electrical insulation; if it is determined that the main circuit breaker and / or the semiconductor switching element cannot perform the breaking function, the stepped safety element chain (6) consists of at least one thermal and / or thermo-mechanical separation step and finally a physical insulation step consisting of a sacrificial metallic conductor trace that can be controlled and decommissioned, sized according to the energy I²t.

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