Starting, off-streaming control function mainly includes the
VSC-HVDC system converting suspending to running or in
turn and the transmission power from zero to a given value,
such normal start, normal off-stream, emergency off-stream
and start again automatically. In order to induce the
extra-voltage and extra-current in the process of starting and
off-streaming, and the lash to the two AC systems, the normal
start and suspend of VSC-HVDC system must have rigid
operation order. If the order is incorrect, it will damage the
devices and cause the system fault.