East Avenue & Queen City Substation Improvement Project
Vermont Electric Power Company proposes to install two air core reactors at the East Avenue substation and one air core reactor at the Queen City substation. During contruction, VELCO will also take the opportunity to make improvements to the physical security of the Queen City subtation.
Needs & Benefits
Recent improvements to the grid have increased the level of quality and reliability of the power that VELCO is able to deliver. However, as the power grid expanded and grew, and as the topology of the system changed, so did the fault current levels on the system. The fault current is the maximum current available should there be a short circuit, such as a ground fault on the system. These faults can occur for a number of reasons, such as wildlife (squirrels, birds, snakes, etc.), vegetation (tree limbs), weather (wind-blown conductors, lightning, etc.), and structural failure (car driving into a pole). When the fault current reaches or exceeds the capability of the existing infrastructure – its electrical ratings – system reliability, worker safety and, in some cases, public safety is at risk. Fault current on the system has now reached a level that must be reduced in order to ensure that the ratings on some electrical components on the distribution system are not exceeded.
VELCO proposes to decrease the available short circuit current on the transmission system by installing air core reactors within the existing East Avenue and Queen City substations. This solution will limit the available fault current on the system to within the electrical ratings of the existing system equipment without reducing the reliability of the power that we deliver.
During construction of the proposed solution at the Queen City Substation, VELCO will also take the opportunity to improve the physical security of the substation by extending the existing fence approximately 10 feet outside the existing control building in the south-west corner of the substation. Currently, the control building is integrated into the station fence which serves as the security perimeter to the substation infrastructure. This change in our fence layout will help us maintain a high level of safety and guard against any potential vandalism or terrorism.
The project consists of the following upgrades:
Component One: Reactor installation at East Avenue substation
- Install two (2), 115kV, three-phase air core reactor assemblies, each consisting of three (3), single-phase reactors, in a stacked configuration. Each single-phase reactor measures approximately 4 feet tall by 7 feet in diameter;
- Install two (2) reactor stands (one for each reactor assembly);
- Install two (2) bus support stands (one for each reactor assembly);
- Install concrete footings and foundations to support the reactor and bus support stands;
- Modify existing bus work as required to integrate the new reactors into the electrical circuit.
Component Two: Reactor installation at Queen City substation
- Install one (1), 115kV, three-phase air core reactor assembly, consisting on three (3), single-phase reactors, in a stacked configuration. Each single-phase reactor measures approximately 4 feet tall by 7 feet in diameter;
- Install one (1) reactor stand;
- Install two (2) conductor support stands;
- Install concrete footings and foundations to support the reactor stand and conductor support stands;
- Movement of conductors outside of the fence to inside the fence to connect to the reactor assembly.
VELCO’s aesthetic consultant reviewed the preliminary design plans and performed a visual analysis of the areas of the proposed Project. The findings indicate the Project will not create any adverse aesthetic impacts. The Project at the Queen City substation is not expected to be visible from the roadside due to existing vegetative screening.
A full analysis of potential aesthetic impacts will be included with the Certificate of Public Good Petition filed with the Public Utility Commission. VELCO does not anticipate adverse aesthetic impacts from the project.
VELCO’s noise consultant, Resource Systems Group Inc. (RSG) assessed the potential noise impacts associated with the additional equipment proposed for each substation. A complete engineering noise analysis will be provided as part of the Certificate of Public Good filing with the Public Utility Commission. VELCO expects no significant noise impacts to the closest residences at the sites.
- Fall 2017
- Public meetings (click here to view public outreach schedule)
- Fall 2017
- Regulatory and permitting process
- Spring 2018
- Expected construction start
- Winter 2018
- Anticipated completion