Bi-directional grid-tied inverter with predictive current control

The objective of this paper is to propose a bidirectional grid-tied inverter (BGI) with predictive current control (PCC). The proposed BGI can be operated either in the grid connection mode (GCM) or the power factor correction mode (PFCM) which are necessary features for the renewable energy supplied DC power system. For the proposed PCC, the duty ratio for the power switch in BGI is determined by the output current and the duty ratio of the previous switching cycle. The proposed PCC will regulate the amplitude and direction of the BGI current as well as the DC bus voltage. In this paper, mathematical expressions of the proposed PCC for both the GCM and PFCM are derived step by step. A 1 kVA BGI for DC power system is built and tested. Experimental results are used to verify the performance of the proposed BGI with PCC.