Predictive Current Control of PMSM Drive Supplied with ۴-Level Diode-Clamped Inverter

A mandatory issue in the control of a permanent magnet synchronous motor (PMSM) drive is to overcome its nonlinear dynamic characteristics. This challenge becomes more severe when a multilevel diode-clamped inverter (DCI) is used for supplying the PMSM drive. In this case, it is indispensable to provide an accurate speed tracking performance as well as the capacitor voltage balance. The model predictive control (MPC) approach can properly solve this issue by considering different objectives in the cost function of the controller. This paper concentrates on the model predictive current control (MPCC) of the PMSM drive fed through a ۴-level DCI. A comparative assessment of the ۴-level DCI and ۲-level VSI is performed in the PMSM drive with the MPCC approach. Different objectives are considered in the MPCC process including the d-q current control, limitation of the stator currents, voltage balance of capacitors, mitigating of the CM voltage, and reduction of the switching frequency. Simulation results reveal the superior dynamic performance and capacitor voltage balance in the suggested MPCC of PMSM drive with the ۴-level DCI. Results manifest that the current total harmonic distortion (THD) and the torque ripple are lower in the PMSM drive with a ۴-level DCI than with the ۲-level VSI. The current THD is reduced from ۸.۶۱% in the ۲-level VSI to ۴.۵۹% in the ۴-level DCI. Moreover, the torque ripple is reduced from ۱.۲ Nm in the ۲-level VSI to ۰.۳۲ Nm in the ۴-level DCI.

کلیدواژه ها:

Capacitor voltage balance ، diode-clamped inverter ، model predictive current control ، permanent magnet synchronous motor ، weighting factor