Direct and alternating currentHVDC grids
HVDC grids represent the next development stage in multi-terminal operation. In terms of their function they work like a meshed AC grid, but have several special features. Since power flow inversion is an essential quality of large-scale meshed grids, only VSC converters come into consideration. As with AC grids, balanced electrical power is also required with DC grids. Before DC grids can be used on a commercial scale, it will be necessary to develop suitable power switches.