Suffolk 500-kV Substation

Completion Date: 2009

Dominion Virginia Power’s Suffolk Substation was the Burns & McDonnell Transmission & Distribution Group's first opportunity to work on Dominion’s 500-kV transmission system. This project provides accommodations for the expansion of the Suffolk Substation with new 500-kV/230-kV, an 840 MVA transformer bank, two 500-kV circuit breakers, a 23-kV low-side breaker and all associated auxiliary equipment.

  • 230-kV, 500-kV protection and control design
  • 230-kV, 500-kV physical design
  • Grounding analysis
  • Transformer oil containment

Burns & McDonnell provided engineering services at Dominion Virginia Power’s Suffolk Substation for the installation of a 500-kV/230-kV autotransformer bank with two 500-kV breakers and one 230-kV breaker. As the first phase of a two-phase plan to install a six-position, 500-kV ring bus with two transformer banks and four lines, this project cut Dominion Virginia Power’s existing 500-kV 531 Line — a portion that travels in the right-of-way adjacent to the Suffolk Substation — from Surry Substation to Yadkin Substation.

For this 500-kV yard addition, Burns & McDonnell provided all facets of physical design — design for rigid bus, strain bus, grounding, conduit, cable scheduling, grounding simulation with CDEGS, foundation, surface voltage gradient, steel structures and lightning protection — and implemented all associated equipment.

System protection work included the addition of two line panels, three breaker panels, one transformer differential panel, one DFR cabinet, two communications processors, three logic controller annunciators and the replacement of two breaker panels. Related design includes one-lines, relay schemes, communication schemes, panel wiring diagrams and wiring diagrams.

  • Separation of a 500-kV transmission line
  • Upgrading existing site to a 500-kV station
  • Four single-phase, 500-kV/230-kV 280 MVA transformers (includes one
    spare transformer) 
  • Two 500-kV Mitsubishi dead tank breakers
  • 12 relay panels
  • 125 VDC, 400 AH battery system and 35A charger