“There are times of the year when you have an elevated fire risk for customers—dry fuel or Santa Ana Winds,” says Charlie Cerezo, a distribution protection and automation engineer with San Diego Gas and Electric (SDG&E). “We used to predict these times throughout the year. Now it seems like it’s all year long.”
These increased risks are a concern for utilities like SDG&E, an investor-owned utility that provides service to 3.7 million people in San Diego and southern Orange County with a service area spanning 4,100 square miles.
Occasionally, an overhead power line (or conductor) can break and fall to the ground—for example, when a car strikes a pole or a line is damaged by a falling tree or lightning. The chances of this happening are minimal, but the results of a broken conductor hitting the ground can be severe.
Traditional protection equipment may detect this fault but take a few seconds to respond. Or, a live conductor can land on high-resistivity earth, dry asphalt, or a concrete surface, creating a high-impedance fault that is hard to detect using traditional equipment. Even when a fault is detected and tripped within a fraction of a second after a conductor hits the ground, if conditions are prime for wildfires, it may be too late.
Chris Bolton, manager of System Protection Automation and Control Engineering at SDG&E, explains, “The risk is to life, property, and territory. A fire doesn't necessarily have to cover many acres to damage or destroy several homes.”
How do you prevent a broken conductor from causing a wildfire? Relying on traditional protective devices might not be enough, especially if the broken conductor causes a high-impedance fault. You’d have to detect the break and cut off power even before the conductor has had a chance to hit the ground. Engineers at SDG&E decided to find a way to do just that, but broken conductors have plagued the industry for years, so it would take innovation, collaboration, and significant testing to come up with a new solution.
“It was an idea,” says Bolton. “That’s all it was. At SDG&E we have the freedom to try new things—to go into a nonoperational environment and test these ideas with a partnership from a third party.”
It’s Like Assembling an Army
The FCP solution alone has involved over seven years of developing settings, testing, validation, and teamwork that have led to more recent hard work in the field, testing and commissioning circuits—a process that requires intense coordination.
“The amount of coordination, work to line up, and people working together to accomplish this is huge,” says Chris Bolton. “So, when our teams go out there to commission everything, it’s like assembling an army.”
Communications teams, SCADA operators, project managers, relay technicians, distribution operators, and more are onsite when a new circuit is being tested and commissioned.
Tanushri Doshi recalls the challenge and excitement of being onsite during an FCP commission. “It was around 110 degrees, and it was 5–7 days of solid work from morning to late evening. But the day we wrapped it up, that was one of the best feelings, to see a circuit in service. It never grows old— seeing the result of everybody’s hard work over the years.”
This exciting collaboration between various departments within SDG&E and SEL has continued on a weekly basis. SEL engineers provide onsite and remote support during commissioning, and Engineering Services and Research and Development teams attend weekly virtual meetings with several engineers from SDG&E to discuss lessons learned, enhancements, and updates to improve the FCP solution.
Jorge Esmerio, an SDG&E protection engineer, attends each week’s meeting to report scenarios, ask questions, and screenshare software to help implement changes for improvements. Speaking of the improvements they’ve made from these meetings and continued collaboration, he says, “I think this solution will just keep getting smarter and better as we learn new things.”
Tanushri Doshi echoes these sentiments from the SEL side: “We started off with pretty much nothing but an idea. It takes a great partnership to see it through, and with SDG&E, it has always been a pleasure.”
So far, SDG&E has implemented seven FCP circuits, with plans for eight more over the coming year through continued collaboration, field work, and weekly meetings. The growing number of these circuits adds a layer of reassurance when it comes to mitigating wildfire risk.
When a new idea can result in an innovative solution like FCP, providing a new layer of safety for customers in the power protection industry, who knows what’s next. But the possibilities around new technology, like synchrophasor data and advanced algorithms in the RTAC, stretch far beyond falling conductors, with the potential for better situational awareness and more reliable service overall.
“Things are looking promising for the future,” says Jorge Esmerio. And as far as the effort it’s taken to get here? “Wow,” he adds, “What a fun journey.”
