Improved Model Predictive Control for Single-Phase Grid-Tied Inverter With Virtual Vectors in the Compacted Solution-Space

Abstract

In this letter, an improved model predictive control (MPC) has been proposed for single-phase grid-tied converter with virtual vectors in a reshaped and compacted solution space, while improving ac power quality, without increase of the virtual vectors number. Combining linear solution space reconstruction method, the global optimization solution space can be shrunken and reshaped in real-time, only relying on grid angle information. Therefore, MPC can select the optimal virtual-vector in a finer and closer solution subspace, then, much finer control effect can be obtained. Implemented by finite-control set MPC with an integrated difference modulator, equivalent fixed double switching frequency at the output can be achieved. Experimental results validate the effectiveness of the proposed methods.