A Deadbeat Predictive Flux-Weakening Control Considering Voltage and Current Constraints for Surface-Mounted PMSMs

To extend the operating range of permanent magnet synchronous motors (PMSMs), it is necessary to inject negative daxis current above the rated speed to reduce the back electromotive force (EMF). In applications requiring rapid flux-weakening response, stringent demands are placed on both the current regulator and the flux-weakening controller. This paper proposes a deadbeat predictive flux-weakening control method that simultaneously considers voltage and current constraints. First, the surface-mounted PMSM (SM-PMSM) model is discretized using an eigenvalue-based approach, and the accurate discrete model is obtained through state decoupling and coordinate transformation. Based on this discrete model, a deadbeat predictive regulator and a flux-weakening controller are designed. When the control commands exceed voltage or current constraints, the commands are modified according to four different cases. The proposed controller achieves fast torque and flux response within the flux-weakening region. Finally, a series of simulations are conducted to validate the theoretical results.