Nuevas reglas para la protección contra sobrecorrientes de fuentes distribuidas

The distributed sources of great development at the present time, using generators or energy storage devices, introduce the necessity of protection devices fundamentally against overcurrents. These distributed sources possess characteristic very different to those of the traditional sources of the electric systems. Such differences have generated numerous inconveniences and damages at the present time, happened due to have extended the concepts and traditional devices of protection directly from the distribution electric systems to the one having distributed sources. The differences that are presented now and that are discussed in the article are: low overcurrent faults, extremely variable fault currents, disappearance of the “strictly in series” circuits, direction change of the fault currents, desensitized of the protective devices, new reclosing approaches, etc. Also stands out the necessity of coexistence and its requirements, of the new protection schemes with the traditional devices in use in the current distribution systems, as function of the penetration level of these distributed sources. It is concluded in the necessity to have protective devices with diverse intelligence degrees, according to their location in the distribution circuit.