Fixed-Switching Frequency Model Predictive Current Control: Closed-Form Solution in the Stationary Reference Frame

Current control of three phase loads is a basic functionality in applications ranging from the control of electrical machines to grid-tied inverters. Commonly adopted approaches fail in case of low switching-to-fundamental frequency ratio, e.g., very high-speed motor drives (high fundamental frequency) and large power inverters (low switching frequency).Model Predictive Control (MPC) has been applied to overcome the limitations of the traditional approach and improve control performance in terms of dynamics and current distortion. The adopted MPC formulation considers the current error at the switching instants of the inverter.The main original contribution is the closed-form solution of the optimization problem, leading to simpler and more efficient implementation, which requires a fixed number of steps. Simulations results are reported for an isotropic Permanent Magnet Synchronous Machine (PMSM), confirming the validity of the approach. Implementation details such as execution time estimation and weight selection are addressed.