Transformation based tracking controller for a GaN microinverter

Differential-mode Ćuk inverter (DMCI) represents a class of single-stage inverter with low device count, modular symmetry, and topological simplicity. Recently, discontinuous modulation scheme (DMS) has been proposed for the DMCI. This paper extends the modular nature of the power stage to the control architecture and proposes a transformation-based tracking controller using adaptive control algorithm for the same. A key challenge in designing a controller for DMS-based DMCI is to take into account the inherent converter nonlinearity and startup transient at the start of every line cycle. Experimental results are provided for startup, steady state, load transition, and total harmonic distortion (THD) using GaN-FET based DMCI, which validate the efficacy of the implemented modular transformation-based tracking controller.