A comparison study of different control strategies for grid-connected three phase two-level power converters

This paper presents a comparison study of different control schemes for grid-connected three phase two-level power converters. All control strategies adopt the double-loop control structure which consists of voltage regulation loop and instantaneous power tracking loop. In the external loop, voltage regulation loop, PI, fuzzy PI, adaptive controllers and PI controller plus extended state observer (ESO) are utilized to regulate the output voltage. The merits, drawbacks and design procedures of four methods are compared, investigated and analyzed. The second order sliding mode (SOSM) controllers are applied into the internal loop, instantaneous power tracking loop, to drive the active power and reactive power tracking their set points. The performance differences of these control strategies are compared through the real simulation.