Influence of Inverter Controller Parameters on the Small-signal Stability of LCC-HVDC System Based on a Practical Project

Abstract

Unreasonable control parameters of the Line Commutated Converter based High Voltage Direct Current (LCC-HVDC) system may induce small-signal instability. This paper studies the impact of inverter controller parameters on steady response of the LCC-HVDC system under weak AC grid condition. Firstly, according to a practical project, the small-signal model of LCC-HVDC system is established based on the switching function. Then, the eigen-analysis method is adopted to study the impact of the controller parameters on the inverter side on the oscillation mode and damping characteristics of the LCC system, and the correctness of results is verified by PSCAD/EMTDC simulation. The conclusion shows that reasonable controller parameters can improve the stability margin of the system.