Multi-In-Feed HVDC interaction studies using small signal stability assessment

This paper presents an analysis of multi-in-feed HVDC interactions using small signal analysis techniques. The modeling details necessary to adequately represent the dynamics of the HVDC converters and the AC network are investigated and the models are validated against an Electromagnetic Transient Simulation program. The paper shows that AC network dynamics must be modeled in order to obtain meaningful results from the small signal stability study. A small test system with two HVDC in-feeds is then used to demonstrate the presence of interactions in that system. The case studies presented in the paper indicate that it is possible to have interactions between the HVDC terminals in an AC system. The paper recommends that a small signal interaction study similar to what is presented in the paper should be performed to identify these interactions.