Back-to-back connection
In HVDC terms, links used to connect neighboring grids are often referred to as “back-to-back” connections, indicating that the distance between the two grids is minimal. Such connections are able to link independent power grids, including those operating at different frequencies, and enable power to flow from one grid to another. This means that generators on either grid can be used to secure the supply of electricity across the extended network. The connections can also improve voltage and frequency stability in the linked grids.
Note: The term “back-to-back connection” is also used to describe a test set-up for electrical devices where a motor and a generator are connected to the same shaft line.