A globally convergent energy-based controller for PM synchronous motors

We apply a recently developed energy based controller design technique for Hamiltonian systems to the speed regulation of permanent magnet synchronous motors. We show that the technique yields a globally convergent closed loop system. The resulting scheme is a static state feedback to which a simple linear observer is added to estimate the unknown load torque. An interesting feature of the design procedure is that it can be easily adapted, by adding some standard practical assumptions, to obtain a simplified scheme which is well known in the drives literature. Thus, the proposed controller constitutes an upgrade to current practice for which, in view of the availability of a complete stability analysis, should be easier to tune and yield improved performance. Experimental results are presented to illustrate the performance of the proposed scheme.