Current Harmonics Minimization of Model-Free Predictive Current Control for PWM Rectifiers Based on Hybrid SVM

Model-based predictive current control using space vector modulation (SVM-MBPCC) is widely used in pulsewidth-modulated (PWM) rectifiers due to the advantages of quick dynamic response and low current harmonics when the system parameters are accurately known. However, it presents increased current harmonics and power tracking errors when there are parameter mismatches. To improve the robustness against parameter variations, model-free predictive current control based on SVM (SVM-MFPCC) is an effective solution. However, its current harmonics are still relatively high due to the use of fixed voltage vector sequences in the whole working point. This article proposes an improved MFPCC based on hybrid SVM (HSVM-MFPCC), which obtains minimal current harmonics without increasing switching frequency while inheriting the strong robustness against parameter variations of conventional MFPCC. The simulation and experimental results show that the current total harmonic distortion (THD) of the proposed method can be reduced above 26% than conventional SVM-MFPCC when the modulation index is above 0.92.