Regulation of DC link voltage in VSC-HVDC to prevent DC voltage instability based on accurate dynamic model

This paper investigates the effect of considering instantaneous power of the intermediary Inductance on the DC voltage stability in Voltage Source Converter-based High Voltage Direct Current (VSC-HVDC) transmission links. Considering the effects of Intermediary Inductance reveal a non-minimum phase zero in transfer function of the DC voltage dynamics such that neglecting this zero might lead to DC voltage instability in case of rectifying operation of inverter. In this paper after calculating the accurate dynamics of the DC voltage, a DC voltage controller has been designed to overcome any instability in either power flow direction of the inverter. Simulation results depict good performance due to utilizing an appropriate controller which has been reclined on the accuracy of the obtained model of the DC voltage dynamics.