Case Study

345kV PDC Addition

Client challenge:

Our client, is a leading sustainable energy company with $38 billion in assets and operations in 24 U.S. states. They came to us for assistance the addition of a phasor data concentrator (PDC) installation for an existing substation. The project addressed the Owner’s compliance with Independent Service Operator – New England (ISO-NE) OP22 regulatory requirements. SGC Engineering provided the expertise to design and configure the PDC system which collects real-time phasor data from 345kV relays in the station. On-site commissioning services were provided, and the project included a field investigations to document the existing GPS clock and to correct the existing station drawings.

How we helped:

SGC Engineering was commissioned to correct the phasor data issues to comply with ISO-NE regulations. The former system required each relay to communicate with a remote PDC at the client’s energy control center over a low speed serial data connection. After analyzing a report by Schweitzer Engineering Labs (SEL) and the field investigation our team determined that the data issues were caused by high latency and GPS clock synchronization issues.

To reduce the latency, a PDC was installed and connected to the station network. Each of the individual relays responsible for measuring phasor data on the 345kV system were connected to the PDC via high speed serial connections or fiber optic connections over the existing Station network.

During the design process and a subsequent site visit, it was determined that the existing GPS clock IRIG-B system exceeded the limitations provided by SEL. Long IRIG-B chains were reconfigured and terminating resistors were added to the end of each chain. All IRIG-B chains were confirmed on-site, and all affected drawings were updated to match the on-site conditions.

Our team was deeply involved in nearly every aspect of the Buxton PDC Addition Project from start to finish. SGC performed the complete protection and control design and field services necessary to install the new PDC, including soliciting pricing for equipment from vendors, and overseeing the PDC installation. SGC assisted with completing outage applications for the affected equipment prior to the installation. SGC prepared the PDC Configuration Settings so that the PDC could collect, archive, and send the phasor data to the central PDC at the client’s energy control center over their fiber optic network.

Powerful results:

The project was completed with no notable issues and our client was thrilled with the SGC’s performance. During testing, it was reported by ISO-NE that all phasor data collection issues were resolved for all relays at Buxton 345kV S/S. All work was completed on time and within budget without putting additional burden on the client and client resources. The project was direct award and not competitively bid, therefore the work was appropriately estimated and demonstrated SGC’s value sales ability.