Offset-Free Robust Adaptive Back-Stepping Speed Control for Uncertain Permanent Magnet Synchronous Motor

This paper proposes a speed-control law for a parametrically uncertain surface-mounted permanent magnet synchronous motor (SPMSM) using a multivariable approach, which robustly and optimally stabilizes the tracking error dynamics using only the lower and upper bounds of the SPMSM parameters. The contributions of this article are twofold. First, both the innerand outer-loop controllers are designed using a multivariable approach; the back-stepping controller design method ensures stability and the offset-free property. Second, it is shown that it is possible to systematically assign the robust global stabilizing control gains by solving an optimization problem. The efficacy of the proposed method is experimentally verified using a 3-kW SPMSM.