Abstract：This paper proposes an advanced small-signal stability model for multi-terminal MMC-HVDC systems based on dynamic phasors and state-space. As ignoring the dynamic process of converter, the traditional models based on quasi-steady state assumption are difficult to reflect the rapid dynamic process of electronic devices. In accordance with active and passive network control strategies for multi-terminal MMC-HVDC, the small-signal stability models based on dynamic phasors are conducted, and related theoretical derivation is carried out. From the simulation analysis of a typical multi-terminal MMC-HVDC network with offshore wind generation and conventional power sources, the comparisons among the advanced small-signal model, electromagnetic-transient model and traditional small-signal state-space model are performed. It is shown that, the advanced small-signal state-space model can successfully follow the electromechanical transient response with small errors, predict the damped oscillations, and reduce the whole simulation time. Consequently, the validity and applicability of the proposed model are well confirmed.
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2017, Vol. 32 
