is a novel DC transmission technology,
which is based on the voltage source converter, the
self-turn-off devices and pulse width modulation technology.
The technique can not only realize the independent decoupling
control of active and reactive power fast, but supply power to
the passive network with no communication between two
stations, and easy to form mu1ti-DC system. In addition,
providing the emergency support of active and reactive power
to the system, it has obvious advantages in improving the
stability and the transmission capacity of the system [1]. In the
prospect of using extensively in new energy, the excellent
characteristics of VSC-HVDC will play an important role for
generating new energy power and paralleling in AC systems in
the future.