A novel power-flow model of multi-terminal VSC-HVDC systems

• Power flow model of M-VSC-HVDC.
• PTP HVDC.
• PWM.
• IEEE-300 bus test system.

This paper proposes a generalized framework for power-flow modeling of voltage-sourced converter (VSC) based multi-terminal high voltage DC (M-VSC-HVDC) network(s). The modeling strategy pertains to the point-to-point (PTP) HVDC network configuration, which is more generic and widely used than its back-to-back (BTB) counterpart. Unlike existing models, the modulation indices of the pulse width modulation (PWM) converters also appear as unknowns in the proposed model. In addition, both the HVDC network topology and the number of converters can be arbitrarily chosen in the generalized model. For the master converter, either the DC side voltage or the modulation index can be chosen as an unknown, which renders the model more versatile. Numerous case studies carried out by applying different control modes to varying topologies of M-VSC-HVDC networks incorporated in the IEEE-300 bus test system validate the model.