Robust Control Invariant Sets and Lyapunov-Based MPC for IPM Synchronous Motor Drives

This paper proposes a novel simplified model predictive control (MPC) scheme for interior permanent-magnet synchronous machines (PMSM) drive systems. The control problem is formulated in the αβ stator flux space. The current-flux relation is eliminated from the MPC formulation and can be implemented as nonlinear map or an affine approximation without affecting the MPC complexity. The model is combined with the Lyapunov-based MPC concept. This scheme is shown to be asymptotically stable using the convex control set (CCS) input constraint with space vector modulation or pulse width modulation and asymptotically set stable using the finite control set (FCS) input constraint (with direct actuation). The stability properties are guaranteed for any cost function that is globally defined and any prediction horizon N ≥ 1. These results are validated using a software-in-the-loop (SiL) platform and an experimental test bench.