Voltage sensitivity-based transient voltage stability analysis considering HVDC recovery characteristics

This paper presents a method based on V-Q sensitivity and modal analysis to study the transient voltage stability of receiving AC network with HVDC feeding. When faults of receiving network occur, HVDC recovery characteristics are analyzed, which have an important effect on voltage stability of receiving network. The model of active power and reactive power time series responding to the recovery characteristics is built for simplicity, which is applied to replace HVDC systems for transient simulation. Based on simulating results, at each of time frames, Q-V sensitivity and modal analysis can be utilized, and the moment when the reactive power consumed by the HVDC systems rising to high values is the main concern to investigate voltage stability. Bus participation factors are calculated by modal analysis and weak voltage area is found out. Finally, a multi-infeed HVDC test system is studied to verify the feasibility of the method.