In future HVDC grids, or ‘Supergrids’, high voltage DC circuit breakers will almost certainly be used in order to remove a faulted element of the HVDC Grid whilst allowing power flow to continue on the remaining grid. However, associated with these HVDC circuit breakers will be the need for a means of fast fault detection, location and isolation. This paper presents a none-conventional approach to protection, drawing parallels with AC protection and highlighting some fundamental differences.