Robust control of a grid-connected converter with an LCL-filter using a combined sliding mode and adaptive controller in a multi-loop framework

This paper proposes a multi-loop controller for current control of a grid-connected inverter with an LCL-filter. The inner loop uses the converter current error as the sliding surface in a Sliding Mode Control (SMC) approach. The model obtained allows the application of an outer Model Reference Adaptive Control (MRAC) for the tracking of the grid current in a robust fashion with disturbance rejection. Simulation results are presented to validate the theoretical analysis.