We often think of our amazing lineworkers when it comes to ensuring safe and reliable power. But there’s another team of unsung heroes at PEC who work behind the scenes to keep the lights on for our members. They work in our substations.
Substations are the fenced yards that house large electric equipment that serve different areas of our communities. These substations are a critical component of the power grid, taking high-voltage electricity from the power plant and converting it into the power that serves your home or business.
Maintaining the complex system of dangerous equipment in our substations is a meticulous and critical task.
“If a substation goes down, thousands of members lose power, so we have a lot of responsibility in monitoring and maintaining this equipment,” PEC Substation Supervisor Ron Moyer said.
The substation has a control house that is home to carefully programmed, maintained, and monitored devices called relays that act as the brain of the substation, constantly monitoring the system. Relays can sense a problem — in the substation or out on the lines — and instruct the relevant breaker to open in a fraction of a second, protecting equipment and isolating the fault so minimal members are affected.
PEC Director of Substation and Transmission Maintenance Jerry Bible explained that a major factor in the reliability of our substations is redundancy. If one relay protection device fails, another one will immediately activate to protect the equipment. And, certain pieces of equipment have backups in case of failure.
“Most substations have two transformers,” Bible said. “If one transformer fails, we switch power to the other one and the customer is immediately back online.”
To work on equipment safely, substation crews sometimes have to de-energize equipment. When equipment can’t be de-energized without interrupting service, a mobile substation is brought in and power is re-routed without causing even a blink to our members. These mobile units serve an enormous role in system reliability, allowing PEC staff to perform wide-scale voltage conversions, maintenance, and construction projects in and around substations.
When building or upgrading substations, every item goes through a series of tests that can take months to complete, in part because every single circuit must be tested. An ongoing upgrade at PEC’s Leander substation required two months of prep work. When the time came to make the upgrade, the crew was able to do so without any service interruption — an impressive feat of engineering.
All the construction, upgrades, and maintenance keep our substation crews very busy. In 2019, we installed and upgraded five distribution substations, completed two substation voltage conversions, and performed 860 substation inspections and maintenance tasks. Because of record growth in our service area, three new substations are scheduled to come online in 2020 alone.
“We look forward to a busy year helping to keep the lights on for our members,” Bible said. “I’m sure we’ll stay busy for years to come.”