Decoupling Control of Cascaded Power Electronic Transformer Based on Feedback Exact Linearization

This article addresses the decoupling control design for cascaded power electronic transformer (PET) in input-series–output-parallel connection. Due to coupling and interaction between submodules substages, essence it is a complex nonlinear system. A strategy based on feedback exact linearization (FEL) developed decouple all objectives so as realize dc-link output voltages fast stabilizing submodule balancing without interactions. Based separation of ac current time-scale dc voltage time-scale, FEL law derived, specific tuning process parameters given desired bandwidths. Taken dynamic influences current-loop, filter, delay into account, further analyses are made compared with dual active bridge (DAB) control-based show improvement effect performance proposed control. Finally, simulation experimental results verify theoretical analysis, which exhibit better features minimal under condition bidirectional changes parameter inconsistency uncertainty.