Performance comparison of Simplified Feedback Linearization control with classical dual loop control for single-phase grid-connected inverters

In Distributed Power Generation Systems (DPGS), the control system of the converter, interfacing the electrical source with the main grid, is generally based on a dual loop cascade control structure where the internal loop is in charge of the current control while the outer loop controls the voltage at the DC link. The DC voltage can be subjected to transient conditions due to the change of the power produced by the source. If the system experiences high and abrupt variations of the DC voltage, the control system designed starting from a small signal linearized model can fail. In this paper, a Simplified Feedback Linearization (SFL) control is designed for a single-phase grid-connected converter. The system is compared with a classical dual loop control in terms of stability and dynamics performances. Simulation and experimental results confirms the effectiveness of the SFL control also in case of high variations of the DC voltage reference.