Three-Phase Unbalance Compensator Using Neutral Point Clamped Multilevel Interleaved Inverter

This paper proposes a three-phase unbalance compensation system using interleaved NPC inverter and a fast current regulation method. The proposed compensator can reduce in volume of passive filters and voltage and current stress on power devices by using NPC and interleaved circuit structure. The proposed current regulation method decouples interference between reactive and unbalance current compensation on d-q rotating frame. Experimental results of the unbalance compensation clarify the proposed system having a capability of a good compensation performance in steady states and a fast current response in transient states. The proposed system is applicable for wide load range and improving power quality of the grid.