Performance Comparison of Voltage Control Strategies of VSC-HVDC Grids

Voltage source converters (VSC) based HVDC grids are a secure alternative for power transmission in the electric regional integration of many countries around the world, and the integration of renewable sources. The main objective of this paper is to compare the dynamic performance of three modes of control of VSC stations the voltage control methods “Control margin voltage” and “Droop control voltage” to show that the droop voltage control strategy has better results than the voltage margin control strategy. The performance of these controllers is evaluated by means of a perturbation on a VSC station that consists of outage of the negative pole over the bipolar converter station in the DC subsystem DSC3 of the CIGRE DC Grid benchmark test system. The dynamic simulation allows conclude that using a strategic voltage control like margin control voltage is possible have a better level of voltage and active power in the lines DC, the establishment time of the system is 6s. The droop control voltage with acceptable levels of voltage and active power can be faster, stabilizing the system at 1s.