A balanced and properly dimensioned grid has the same current flowing in each of its 3 phases, and no current in its neutral (or earth) return line. However a distribution grid continuously evolves, with its ever changing loads and their varying characteristics (e.g. harmonics generation), and distributed dynamic intermittent renewable energy sources (RES). So detecting and locating earth faults (as in the diagram) on both MV and LV distribution grids can be difficult, costly and time consuming.
Earth faults on traditional high-impedance static networks generate hundreds of amps, are readily detected, but are very unsafe.
While earth faults on “fault tolerant” isolated-neutral networks can range from less than an amp to hundreds of amps and are inherently safer, but much more difficult to detect and locate. Their wide range of fault currents can overload and destroy sensors, or not be detected at all.
In addition, the resilient nature of such networks, means that the direction of the fault current can dynamically change and is critical to detect the source of cascading failures.
The ADMS Distributed Network System (DSN) uses unique state-of-the-art sensors to accurately, reliably and cost-effectively detect all such faults, and their direction, to low fault currents of < 1 Amp
Contact us for an ebook on “Reducing Distribution Outages by Low Cost LV Monitoring” to find out how to transform your distribution grid.