VSC Transmission Operating Under Unbalanced AC Conditions—Analysis and Control Design
Abstract—This paper presents an analysis and a new control
design of a voltage-source converter (VSC) transmission system
operating under unbalanced network conditions. The system
is analyzed in the positive and negative synchronous reference
frames. The proposed control strategy contains a main controller
and an auxiliary controller. The main controller is implemented in
the positive d–q frame using decoupling control without involving
positive/negative-sequence decomposition. The auxiliary controller
is implemented in the negative-sequence d–q frame using
cross-coupling control of negative-sequence current. Simulation
results using the SIMULINK power system blockset show good
performance of the proposed control strategy for a 300-MW
300-kV dc VSC transmission system during both balanced conditions
and unbalanced conditions as may be caused by a solid
single-phase-to-ground fault.
Reference:
1.0 IEEE Transaction Paper - Weblink