Bond Graph and Flatness-Based Control of a Salient Permanent Magnetic Synchronous Motor

This paper deals with flatness-based control of a salient permanent-magnet synchronous motor in the bond graph (BG) domain. It develops two main points. The first proposes and develops a new flat outputs identification procedure valid for multiple-input non-linear BG models without elements in derivative causality assignment. This procedure exploits a variational (tangent) BG model obtained by using Kähler differentials. The second deals with control design based on physical system decomposition into electrical, mechanical, and coupling submodels. Each loop of the decomposition tracks a reference for the local flat output of the corresponding subsystem. This decomposition enables the designing of a control block for each submodel by means of system inversion using the concept of bicausality. Then, the resulting blocks are concatenated in order to build the global controller. Finally, the global stability of the feedback system for both cases (known and unknown load torques) is tested and the control scheme is assessed through simulations in order to illustrate the performances of the method.