Impact of AC-line-emulation controllers of VSC-HVDC links on inter-area-oscillation damping

This paper presents a fundamental study on the impact of AC-line-emulation controllers of High Voltage Direct Current links based on Voltage Source Converters (VSC-HVDC) on inter-area-oscillation damping. The analysis has been carried out using eigenvalue and frequency-domain methods. The results presented in the paper show that an AC-line-emulation controller in a VSC-HVDC link can have either a positive or negative impact on the damping ratio of inter-area modes, depending on the value of the filter time constant of the controller. The study concludes that the filter time constant must be high enough to avoid negative interactions of this control alternative on power oscillations and the paper provides guidelines for the design of this parameter.