Details:

Project: Maritime Link 500 MW VSC

Service: VSC HVDC

Client: ENL

Country: Canada

Year: 2012 — 2013

Overview:

The Maritime Link is a 500 MW +/- 200 kV point-to-point VSC HVDC system connecting the Island of Newfoundland to Nova Scotia via overhead transmission line and submarine cable. The Newfoundland terminal of the VSC link is electrically close to the inverter terminal of a 900 MW 2-terminal LCC HVDC link connecting Labrador to Newfound Island (Labrador Island Link). Therefore, possible interaction of the HVDC links was important to consider. TGS performed the pre-specification studies and developed the technical specification for the Maritime Link VSC converters.

TGS Study services:

  • Custom PSCAD VSC HVDC Model & Reduced AC System Model Development
  • AC System Network Reduction — performed using PSS/E
  • Detailed Electromagnetic Transient Studies — performed using PSCAD
  • Harmonic Impedance Scans — at the VSC HVDC terminals
  • Interaction Study — performed using in-house small signal tool TGSSR

TGS Equipment & Project Execution Services:

  • Development of the Technical Specification
  • Witnessing of VSC valve type tests

Challenges:

Needed to develop controls to operate the VSC under extremely weak short circuit levels.