Interleaving quasi-sliding mode control of parallel-connected inverters

An interleaving fixed switching frequency quasi-sliding control algorithm based on the zero average dynamics (ZAD) approach is reported and applied to the design of a modular system of parallel-connected single-phase inverters. This approach is used in a laboratory prototype of three inverters with an FPGA control-based implementation embedding this algorithm. Experimental results are provided to illustrate the design features in terms of AC output voltage regulation, balanced current sharing among mismatched modules, interleaved fixed switching frequency operation and robustness with respect to load variations.