Model predictive current control of a grid connected converter with LCL-filter

A method to control the output current of a three-phase grid-tied inverter is presented. An LCL-filter is used to reduce the current distortion injected into the grid. The objective is to minimise current distortion and switching frequency to reduce losses. The control approach is based on finite control set model predictive control with sphere decoding to make the problem computationally tractable for long horizons. A mathematical model was derived that extends on previous work by incorporating the effect of a grid-voltage to the system. The control strategy was evaluated through simulation. The results indicate that this control strategy can achieve the objectives for its application mentioned in the paper.