Unified Control Strategy for Microgrid Solid-State Transformers

Solid-state transformers (SST) are particularly useful components in distributed generation systems (DG). This research approaches the control of the SST in a more comprehensive and an organized way. It proposes a compact, versatile and an efficient unified control strategy. This proposal gives rise to three more proposals. i) A method to mitigate the current harmonic distortion which is uniquely software-based and ii) An efficient low-voltage ride-through (LVRT) scheme. Both of those functions come at no extra cost using the proposed unified control scheme. These proposals further demonstrate the proposed strategy’s ability to accommodate further features and modifications. A further contribution to this research addresses the unbalanced load conditions. It proposes a simple, cost-free modification to a resonant filter - making it suitable for the proposed control strategy thus maintaining its simplicity without compromising its practicality. All the proposals of this research have been validated through simulation in Simulink.