Increase in Local CFII in Multi-Infeed HVDC System with STATCOM

Abstract

This paper investigates the increase in Local Commutation Failure Immunity Index (LCFII) for multi-infeed HVDC configurations. The HVDC is considered most sustainable solution to transfer bulk power over long distance. The commutation failure is an adverse unavoidable phenomenon which suspends power transfer temporarily. The literature isn’t clear about the effect of multi-infeed interaction factor (MIIF) on LCFII. This research estimates the increase in LCFII with MIIF. It is investigated that with higher MIIF the LCFII increases. The higher MIIF causes reactive power support to flow from remote converter to local converter which improves the voltage profile, consequently it reduces chances of commutation failure. A power flow approach is used here to estimate the impact of reactive power support on LCFII. The theory presented is verified using PSCAD/EMTDC simulations and the results clearly validate the concept presented.