Distribution Automation: Communication Not Required

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Without a doubt, using communications for distribution automation (DA) provides a plethora of advantages for a utility’s grid. But are communications required to do distribution automation? Certainly not.

We’re not suggesting utilities skip consideration of a communication-based system, but distribution automation is not always contingent on communication. Utilities have technology available to them, such as advanced fault interrupters with highly accurate sensing and sophisticated controls, that can support basic DA. And this can be important for places where, because of tough topography, cost, or other issues, communication-based systems aren’t feasible.

An example for doing DA without communications through the use of the electrical pulses for the purpose of improving protection coordination. Fault interrupters work together to automatically and quickly hunt down and isolate faults by sending small pulses of current along the feeder, without using communications, to prevent sustained outages for customers. This technology simplifies and improves coordination while providing greater segmentation.

After the device reaches lockout, an automated loop-restoration scheme can be used to further improve reliability. Using loss-of-voltage timers inherent in the controls, the fault interrupters can reconfigure the feeder and restore power to unfaulted feeder sections, without relying on communications. During reconfiguration, additional pulses of current are sent to prevent the fault interrupters from blindly closing into the fault, thus reducing system stress and improving power quality. There are several examples of technology native in today’s highly intelligent fault interrupters that allow DA without the use of communications.

Non-communicating DA technologies are also expanding to other areas of the grid where they didn’t exist before. Cutout-mounted vacuum interrupters can now be installed in lieu of fuse cutouts used to protect distribution laterals and pole-mounted distribution transformers. Unlike fuses, these devices can automatically reclose and restore power to customers. Because most distribution faults are transient, reliability is greatly improved and truck rolls to replace blown fuses are avoided.

Sure, communications would allow utilities to implement more advanced and elaborate protection and restoration schemes, but utilities shouldn’t let anyone try to convince them they need communications for distribution automation. With advanced technology, a utility can do distribution automation in certain applications without communications.

I’d be interested in learning your thoughts on this topic in the Comments section below.