Modified predictive direct power control of voltage-sourced converters under network voltage unbalance conditions

This paper proposed a novel multi-objective predictive direct power control (P-DPC) approach to achieve three different control targets dependent on the operation of the network: eliminating negative sequence currents, eliminating active power oscillation and eliminating reactive power oscillation. The proposed P-DPC strategy decouples positive and negative sequence components in the stationary reference frame without the necessity of the synchronous speed d-q transformation and the complicated design of current inner loop. Power compensations are injected into power references for different control objectives, respectively. Simulation studies verified the effectiveness of the proposed multi-objective P-DPC strategy under unbalanced grid voltage conditions.