Stability Assessment of Uncertain AC/DC System

  • Rian Fatah Mochamad

Student thesis: Phd


This research has been conducted in order to gain a greater understanding of how the increasing penetration of renewable energy sources and Voltage Source Converter (VSC) -a type of high voltage direct current (HVDC) converter, affect the stability of power systems. Upon completing the research, this thesis has thoroughly assessed the stability of uncertain mixed AC/DC system considering four types of stability, several different connection topologies of VSC-HVDC -a type of high voltage direct current (HVDC) converter and a combination of varying renewable energy sources (RES) penetration levels and loading conditions. Two types of stability assessment techniques, namely deterministic and probabilistic have been performed. This thesis has investigated and established the multi-stability operating boundaries with high penetration of RES and VSC-HVDCs. A comprehensive assessment on the impact of VSC-HVDC connection topologies on the interdependency of power system stabilities also has been completed. Moreover, priority ranking of critical uncertainties for each stability types and its physical importance have been identified. This thesis provides a means to thoroughly understand the stability of uncertain mixed AC/DC systems. The methodologies outlined within this thesis will enable a greater understanding of the complex stability related phenomena in future volatile power systems.
Date of Award31 Dec 2019
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorJovica Milanovic (Supervisor) & Robin Preece (Supervisor)


  • mixed AC/DC system
  • renewable energy source
  • voltage stability
  • small-disturbance stability
  • large-disturbance stability
  • frequency stability

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