Finite-Set Quasi-Sliding Mode Predictive Control of LC-Filtered Voltage Source Inverters

Three-phase voltage source inverters (VSIs) with output LC filter are preferred topologies to provide voltage and frequency support for islanded ac microgrids. This article proposes a finite-set quasi-sliding model predictive control (FS-QSMPC) scheme for LC-filtered VSIs to improve the output-voltage quality. By explicitly including a predictive sliding-mode function into the cost function, reduced steady-state ripple and enhanced robustness to model mismatches are achieved. Besides, theoretical analysis of stability and robustness for the proposed FS-QSMPC is given. Analytical tuning of the weighting factor is also derived to decrease the tuning effort. Simulations and experiments verify the presented approach.