A Comparative Study of the Traditional FS-MPC and the Proposed CSF-PCC for the Three-Phase Grid-Connected Inverters

Traditional finite set model predictive control (FS-MPC) and a proposed constant switching frequency predictive current control (CSF-PCC) for the three-phase grid-connected inverter are compared in this paper. Traditional FS-MPC is superior in terms of transient performance and flexibility. However, its variable switching frequency makes the total harmonics distortion (THD) of current spread in the whole switching range. With a voltage vector dichotomy solution approach, a constant frequency based CSF-PCC is proposed. According to the comparison with the traditional FS-MPC method, the proposed CSF-PCC not only can achieve the same good dynamic performance with the FS-MPC, but also has much smaller steady-state current ripple, as well as can reduce the current THD and locate the current harmonic in a certain range for easy filter design.