Virtual flux predictive direct power control of three-level multi-terminal VSC-HVDC transmission system

In this paper, a virtual flux predictive direct power control-space vector modulation is proposed to control three-level multi-terminal voltage source converter HVDC transmission system. The main goal of the proposed control is to regulate the power flow independently in order to minimize instantaneous active and reactive power errors, operate with constant switching and produce sinusoidal currents with low harmonic distortion. Three-level space vector modulation is achieved to balancing the DC capacitors of three-level converters based on the effective use of the redundant switching states of voltage vectors. The obtained results are compared with the conventional direct power control. These outcomes allow to exhibit excellent transient response during a range of operating conditions.