Power hardware-in-the-loop validation of primary frequency robust control in stand-alone microgrids with storage units

This paper describes a multi-variable robust control scheme for frequency regulation in a diesel–photovoltaic–supercapacitor hybrid power generation system operating in stand-alone mode. The proposed control structure relies on a two-level architecture, with conventional PI-based current tracking controllers placed on the lower control level and receiving references from an ℋ_∞ -control-based upper level. The specific engineering demands of microgrid operation are cast into an ℋ_∞ control formalism. A rapid-prototyping test bench composed of a real supercapacitor-based energy storage system and an emulated diesel–photovoltaic–load grid is developed using real-time digital simulators, namely RT-LAB ^ and dSPACE ^ , in order to experimentally validate the proposed frequency robust control strategy under realistic operating conditions.