Integrating Phase-Shifted Pulse-Width Modulation to Model Predictive Current Control of Modular Multilevel Converters

Model predictive current control (MPCC) is a promising candidate for modular multilevel converters (MMCs) due to its advantages of direct modeling and quick dynamic response. However, the conventional MPCC experiences high load current and circulating current tracking errors since only one switching state is selected and applied during one control period. To address these issues, this paper proposes an MPCC with integrated phase-shifted pulse-width modulation (PS-PWM) for improving the steady-state control performance. The arm voltages are considered as a whole to implement the proposed MPCC. The optimal duty cycle is obtained based on the load and circulating current tracking errors minimization and applied using a PS-PWM. As a result, the tedious tuning process of weighting factor is eliminated and a better steady-state performance is achieved with the same sampling frequency. Experimental results are presented to demonstrate the effectiveness of the proposed MPCC.