Fundamental Analysis of Voltage and Power Stability of Single-Infeed Voltage-Source Converter HVDC Systems

This paper presents a comprehensive and fundamental analysis of the steady-state voltage and power stability of single-infeed voltage-source converter (VSC) HVDC systems. The classical stability concepts developed for such analysis of line-commutated converter (LCC) HVDC systems are also shown to be applicable to VSC-HVDC systems as well. The voltage-support capability and power delivery capacity of the VSC-HVDC system to a weak receiving ac system are also shown in relation to the LCC-HVDC system. These contributions are shown to be particularly effective for the VSC-HVDC system having a typical reactive ac power control but supplemented in this work with an ac voltage modulation control. Time-domain dynamic simulations on a single-infeed VSC-HVDC system also validated the fundamental derivations in this work.