PROJECT TITLE :

Individual Phase Current Control Based on Optimal Zero-Sequence Current Separation for a Star-Connected Cascade STATCOM Under Unbalanced Conditions

ABSTRACT:

This paper proposes a private phase current control (IPCC) methodology primarily based on optimal zero-sequence current separation for star-connected cascade STATCOMs below unbalanced grid voltage. The IPCC is adopted to induce better adaptation to unbalanced conditions. Each cluster of the cascade STATCOM has its own section current control loop and dc-voltage feedback loop, and it can generate the required negative-sequence current automatically to rebalance power. But, the zero-sequence current that is unnecessary and harmful in star configuration is introduced in the method. An optimal zero-sequence current separation is presented to get rid of the zero-sequence current by reconstructing the reactive current command. This improved IPCC allows star-connected STATCOMs adapt to unbalanced conditions while not the need for any power balancing algorithms. Conjointly, the operation vary of the proposed control method is analyzed. Simulation analysis studies are performed to verify the operation vary analysis, and therefore the experimental operation is tested on a 25-level ±10 Mvar/10-kV STATCOM product put in at a wind farm.