The job to “keep the lights on” is the hero’s work of the utility engineers and line crews who put themselves in harm’s way in bad weather. Snow, ice and freezing rain is a dreaded situation for any utility, but add to that an aging infrastructure and failing assets and you have a treacherous combination. According to the Weather Channel, there is a new high tech solution that can make response a lot easier and safer. The answer is Tollgrade LightHouse® Smart Grid Sensors. Here are a few of our favorite recent examples of how Tollgrade helped utilities get the lights back on faster.
Restoring Power in Six Feet of Snow
This past winter, one northeastern utility was buried under six feet of snow. Roads were impassable and the Governor issued a warning urging residents to stay home. Luckily, six weeks earlier this utility installed Tollgrade LightHouse Smart Grid Sensors and reported an outage that was impacting 6,000 residents in less than two minutes. Because the Sensors could additionally report the outage location, the utility was able to send the crew exactly to the segment of the grid that was in trouble and avoid hazardous foot patrols or unnecessary driving. By driving directly to the switching location, the crews had power restored in about five hours. Without sensors, its estimated those 6,000 residents would have been sitting in the dark for 20 hours or more with six feet of snow at their doorsteps.
Finding Aging, Failing Equipment About to Cause a Significant Outage
On December 3, 2014, LightHouse Smart Grid Sensors installed on a 34.5kV network started reporting Line Disturbances at about 16:00 hours on B and C phases of the distribution network at a large northeastern utility in the United States. Over the course of the next several hours, additional Line Disturbances were reported with a similar waveform shape. The sensors located the origin of the fault so there was no need to patrol the entire 20 mile section of power lines looking for problems in the dark.
When the troubleman arrived at the substation, he found a voltage regulator arcing internally and about to fail. Seeing the gravity of the situation, the utility acted immediately and in the next hour was able to prepare a plan of attack to isolate the equipment and make the repairs. Had the voltage regulator ruptured, it would have spilled oil onto the ground and caused a fault which would have blown the 34.5kV fuses, interrupting power to about 2,000 customers for two to three hours causing a total 360,000 Customer Minutes Interrupted (CMI).
Tollgrade LightHouse Sensors were the key to identifying this failing device. There were no visual indications that the voltage regulator was about to fail. The fault current was too low to be detected by the substation relays connected to the circuit breaker. Therefore, the circuit breaker did not have any momentary interruptions and there was no notification by any SCADA devices. Without Tollgrade LightHouse Sensors, this utility would have been dealing with a full power outage impacting 2,000 customers.
Ready to learn more about how Tollgrade can help your utility? Download our Predictive Grid Quarterly Report to see more examples of a smarter grid in action.