Interconnection

We have selected to distinguish interconnections within a grid and new interconnections between grids.

By this we mean constructing or strengthening a circuit between two points that belongs to the same synchronous grid (or group of grids). If the electrical distance is short or of moderate length, it is often enough to build one or two uncompensated AC-lines or cables. But with increasing distance, the addition of FACTS (Flexible AC Transmission Systems) and utilising HVDC can be the optimum choice.

ABB Case Stories of typical applications:

• The Namibia-South Africa interconnection (AC)
• The Manitoba-Minnesota interconnection, Canada-USA (AC)
• The Zimbabwe-Botswana-South Africa interconnection (AC)
• Western USA interconnection (Pacific Intertie) (AC and HVDC)
• Finland - Sweden submarine interconnection (HVDC)
• Cross Sound Cable, USA (HVDC Light)

Further applications:

• Controlled interconnections within a city (HVDC Light)

This means linking two separate networks that are not running in synchronism so that exchange of power can take place. If they are linked by an AC circuit assuming the same nominal frequency), then the combined network becomes one synchronous grid with common frequency control. But if the power transfer is on a HVDC link, the networks can maintain their separate frequencies.

ABB Case Stories of typical applications:

• North-South interconnection, Brazil (AC)
• Unique FACTS interconnection between the USA and Mexico (HVDC Light)
• The Scandinavia - Northern Europe interconnection (HVDC)
• The Argentina - Brazil interconnection (HVDC)