Finite Control Set–Model Predictive Control of H8 Inverter Considering Dead-Time Effect for PMSM Drive Systems With Reduced Conducted Common-Mode EMI and Current Distortions

Abstract

To reduce the conducted common-mode (CM) electromagnetic interference (EMI) and current total harmonic distortion (THD) in permanent magnet synchronous motor drive systems, this article proposes a finite control set–model predictive control (FCS–MPC) method for an H8 inverter considering the dead-time (DT) effect. In a real system, the DT causes unexpected peak common-mode voltages (CMVs) and distortion of the inverter output voltage, which deteriorates both the CM EMI and current THD. The conventional double active voltage vector (VV) based MPC methods with an H6 inverter may not be a good solution because of the numerous CMV variations and the limit of the VV transitions. In contrast, the proposed FCS–MPC method allows all VV transitions possible without the peak CMVs by instantly operating the series-connected switch of the H8 inverter based on the previous VV, predicted current sector, and next optimal VV. Furthermore, the nonlinearity of the inverter output voltage due to the DT is compensated in a discrete-time model used for the current prediction, considering the calculation delay of the digital controller. Consequently, the current THD as well as the CM EMI can be improved. The simulation and experimental results are presented to verify the effectiveness of the proposed method.