Analysis of the interactions between close HVDC links inserted in an AC grid

This paper focuses on interaction between two closed-connected high-voltage DC (HVDC) lines. This interaction is studied by employing electromagnetic transients (EMT)-based nonlinear modeling in MATLAB
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/Simulink
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software environment. In order to describe the mechanism behind the HVDCs interaction, both nonlinear time-domain simulations and modal analysis of the coupled HVDC links, have been performed. System small-signal stability has been assessed and the path of interactions has been identified by computing the participations of various states in the oscillatory modes.