This paper proposes an improved model predictive current control (MPC) based on discrete space vector modulation (DSVM) to achieve high performance of output current waveforms and a fixed switching frequency. The conventional finite set model predictive control (FS-MPC) has several disadvantages such as large current ripples, variable switching frequency, and excessive acoustic noise. To overcome these problems, the proposed method adapts the DSVM strategy. The proposed DSVM strategy enables to obtain a large number of virtual voltage vectors without complex initialization process or lookup table, which are the drawbacks of the conventional DSVM strategies. To avoid the high computational burden problem caused by a large amount of virtual voltage vectors, the proposed method minimizes the number of candidate voltage vectors by selecting the optimal region in the space vector diagram. Since the MPC and DSVM strategies are adapted in the proposed method, the fast dynamic response and high quality of the output currents are achieved. The simulation and experimental results were presented to verify the effectiveness and performance of the proposed method using a two-level grid-connected voltage source inverter.
