VSC-HVDC station with SSSC characteristics

Commercial installations of voltage-source converter-high voltage direct current (VSC-HVDC) are now in service as asynchronous link and as underwater/underground dc transmission. The research reported in this paper is directed to providing VSC-HVDC with synchronizing power and damping power so that after a transient, the steady-state is reached in minimal time. Damping power is achieved by injecting incremental power which is proportional to the frequency deviation measured by a phase lock loop. Synchronizing power is achieved by: 1) introducing a delay in the power measurement and 2) by incorporating a static synchronous series compensation in the VSC-station. The effectiveness of both the synchronizing and damping power is demonstrated through digital simulations of a turbine-generator system which is connected to a VSC-HVDC Station. It is shown that with the synchronizing power and damping power, recovery from the fault disturbance is very much faster. Index Terms--High voltage dc (HVDC) transmission, static synchronous series compensation (SSSC), synchronizing power, voltage-source converter (VSC), voltage-source converter-high voltage direct current (VSCHVDC).