Project: Nelson River HVDC Bipoles 1 & 2

Service: LCC HVDC

Client: Manitoba Hydro

Country: Canada

Year: 2013 — on-going


Manitoba Hydro currently has two LCC HVDC bipoles that bring hydroelectric power from the far north of Manitoba to the southern load center and for export to the USA. Manitoba Hydro is currently building a third +/-500 kV 2000 MW LCC HVDC bipole. TGS has provided study services for Manitoba Hydro as shown below:

TGS Study services:

  • Insulation Coordination: Arrester replacement study — performed using PSCAD
    • Defining the staging sequence to replace the gapped arresters with gapless arresters
    • Determining the required duty of the new gapless arresters caused by temporary and switching overvoltages
    • Development of detailed electromagnetic transient model - PSCAD
    • Verification of the adequacy of the proposed arresters
  • Bypass switch study — performed using PSCAD
    • Determining the impact on existing equipment by removing the existing bypass vacuum switch.
    • Determine equipment ratings for the new bypass switch
  • Paralleling Study — performed using PSCAD
    • Looked at the impact of running the existing BPII with the newly proposed BPIII. This study looked at BPIII being either a LCC converter or a VSC converter
  • AC on DC Study — performed using PSCAD and PSSE
    • Looked at if Manitoba Hydro suffered a catastrophic failure of the converter stations, how much power could be transmitted by converting the dc lines to ac lines.
  • RTDS Assistance — performed using RTDS
    • Assisting Manitoba Hydro in developing replica controls for BPI and BPII for use with their RTDS system


Most of the studies listed above deal with integrating new equipment with existing equipment, so all studies need to ensure that any retained equipment’s ratings are not exceeded and determine how to stage the integration of the new equipment in order to minimize outages.