Comparison of controllers of hybrid HVDC link in multi-infeed application

Abstract

The increasing power demand in the modern power sector makes inversion of two or more HVDC links in to the same AC system inevitable leading to a multi-infeed HVDC (MI-HVDC) system. With LCC-HVDC, the problems of inversion into weak systems are more pronounced in MI-HVDC systems. These difficulties can be overcome by forming a hybrid MI-HVDC system with one link LCC-HVDC and the other as a hybrid link with a thyristor based rectifier and voltage sourced converter based inverter. The hybrid LCC-VSC link needs a thorough study for its application in multi-infeed systems. This paper emphasizes on a comparative study of different controllers of VSC inverter of the hybrid HVDC link in a multi-infeed application. The simulation study is carried out in the PSCAD/EMTDC environment.