Versant Power to add technology that benefits New England transmission system

The new synchronous condenser will regulate varying electrical voltage

Ellsworth, ME— Over the past few months, Versant crews have been preparing the Boggy Brook substation in Ellsworth to accommodate new equipment. The incoming device, called a synchronous condenser, will be the first of its kind on Versant’s transmission system.

The need for this equipment was identified in a 2021 ISO-New England study. The study found situations that could potentially cause voltage irregularity within the Down East loop electrical system, which extends from the Bangor area to Epping.

To regulate voltage in certain scenarios, such as the addition of wind generation, the study found that the Down East Loop system could benefit from an increase in short circuit current, which has several benefits. Short circuit current stabilizes power supply for renewable energy sources, provides the necessary power to ensure reliable service, detects faults and helps maintain voltage levels in the event of service interruptions.

The synchronous condenser can be thought of as a giant synchronous motor that provides short circuit current as well as voltage stability. The 12-foot-tall, 100-ton device adds stability to the system, coupling electrical properties with physical characteristics. The synchronous motor rotates at set revolutions per minute, and the mass of the rotor adds inertia, resisting overvoltage in the case of excess generation, or providing voltage stabilization during times when generation is lower.

“If you think of power going to the transmission system like water flowing through a pipe, and then a hole appears in the pipe causing a leak, you can think of short circuit current as the backup water tank,” said Versant Project Manager Brian Green. “The synchronous condenser is generating that current and keeping power supply flowing on the transmission system.”

The project also includes new power inductors that are electrically connected on a ring of breakers with the synchronous condenser. The inductors will help manage the reactive power on the transmission system. This will help to ensure reliable service to thousands of customers not just in Down East Maine, but throughout the New England transmission system. The Boggy Brook substation work is an ISO-New England pool transmission facility project, which means all members contribute to the cost and benefit from it.

Preliminary work at the site has consisted of groundwork for the foundations of the electrical structures and constructing a building to house the condenser. Project planning, construction and configuration involve Versant engineers, line crews, power system technicians, safety, environmental, and system operations team members, along with the help of WEG, TRC Engineering and Cianbro.

The project is expected to be completed in mid-2024. For more Versant news, please visit versantpower.com.