Feasibility studies and engineering support for Manitoba Hydro

For decades, Manitoba Hydro has used hydroelectric power along the northern Nelson River paired with two line-commutated converter (LCC) high-voltage direct current (HVDC) bipoles to transmit the generated power to a load center near Winnipeg and for export to the US.

After a storm at the end of the 20th century caused damage to both lines, the utility began planning for a third, geographically separate overhead line with a capacity of 500 kV, 2,000 MW to improve reliability, which was finalised in the late 2010s.

Bipole configurations can offer more capacity and flexibility in connecting grids and transporting energy over long distances, as compared with monopole configurations.

Prior to the installation of the third LLC HVDC bipole, Manitoba Hydro retained Ramboll to investigate the feasibility of two technologies – voltage source converter (VSC) and the standard LCC. Ramboll’s experts conducted feasibility studies to compare the use of LCC technology to the use of VSC technology for this new HVDC bipole. We also developed the full technical specification for the VSC option (2300 MW, +/- 500 kV VSC bipole), which was released to suppliers as an option to bid using VSC technology instead of LCC technology.

Ramboll’s work for the client included a transient stability study comparing the two options for frequency performance, interactions with existing bipoles, and requirements for synchronous condensers and VSC power transfer reduction. An electromagnetic transient (EMT) study and a full interaction study using Ramboll’s in-house subsynchronous resonance (SSR) tool was also performed. Further, the team provided ongoing support for design review, witness of factory testing, and commissioning for the chosen LCC technology.

Although Ramboll’s findings showed that it was feasible and there were potential benefits to the newer VSC technology, the client ultimately decided to propose LCC solutions, which is what was built and in operation today.

^References

^{D.A.N. Jacobson, P. Wang, C. Karawita, R. Ostash, M. Mohaddes, B. Jacobson, “Planning the Next Nelson River HVDC Development Phase Considering LCC vs. VSC Technology”, CIGRÉ, Paper B4-103, Paris 2012.}

^{S. Zoroofi, D.H.R Suriyaarachchi, D. Kell, M. Mohaddes, P. Wang, D. Jacobson, “Investigation of Paralleling Bipole II and the Future Bipole III in Nelson River HVDC System”, IET International Conference on AC and DC Power Transmission (ACDC), Birmingham UK 2012.}

^{D.A.N. Jacobson, P. Wang, R. Ostash, M. Mohaddes, M. Rashwan, “A Preliminary Look at the Feasibility of VSC HVDC in Manitoba”, IEEE, Electrical Power and Energy Conference, Winnipeg Canada 2011.}