Voltage stability analysis of multi-infeed HVDC systems using small-signal stability assessment

This paper presents an analysis of multi-infeed HVDC systems voltage stability using small-signal analysis techniques (eigen-structure analysis). A correlation ratio relating to voltage stability is put forward. A small test system with two HVDC infeeds is built to study the voltage stability of the multi-infeed HVDC system. Then the detailed dynamic models of the HVDC system including DC system control model, the generator, the induction motor load and the AC network are investigated. The case studies presented in this paper indicate that the voltage stability correlation ratio (VSCR) can effectively identify the critical elements which strongly correlate with voltage stability in multi-infeed HVDC systems.