Batteries Included

When discussing the development of the utility "smart grid" infrastructure, most people think of adding advanced metering devices to homes and businesses. The concept of adding automation and distributed intelligence in utility distribution networks has been in process for almost two decades, however. One area of signifi cant progress is the creation of "self-healing" distribution networks, or zones where intelligent feeder switching and protective devices communicate in real time to isolate faults and restore service in seconds without waiting for supervisory control and data acquisition (SCADA) commands from utility network control centers. This basic concept has been taken to the next level by adding distributed energy storage in the grid to allow networks occupying fairly large areas to continue to operate as selfpowered "island" power grids in the event of transmission feeder loss.