An improved second-order sliding mode control for the distributed generation system in stand-alone and grid-connected modes

The paper presents an innovative application of an improved second-order sliding mode control, (super-twisting technique) on the distributed generation system. The meritorious performance of the presented super-twisting technique is validated by comparing its performance to several versions of the SMC (regular super-twisting, conventional first-order SMC and proposed version of the first-order SMC). The presented super-twisting technique is used to develop a novel control scheme in order to enable the distributed generation system to work in a grid-connected mode and a stand-alone mode, and to seamlessly transfer from a specific mode to another. The core of the adopted distributed generation system is a distributed generation unit, which is the multilevel, 5-level, diode clamped inverter so as to minimize the injected switching harmonics. Eventually, the simulation results are depicted to show the merits of the presented super-twisting technique and how the proposed control scheme operates the distributed generation system such that its output power/voltage can be efficiently controlled in different modes of operation.