Analysis and control of the permanent magnet synchronous motor model

The permanent magnet synchronous motor (PMSM) is rapidly becoming a cornerstone of diesel–electric ship propulsion. The dynamics of the PMSM are highly nonlinear and require thorough understanding to enable efficient operation. In this work, bifurcation analysis and multi-objective nonlinear model predictive control (NMPC) are performed on a PMSM model. The PMSM is frequently used for diesel–electric ship propulsion. Bifurcation analysis is a powerful mathematical tool used to address the nonlinear dynamics of such processes. Several factors must be considered, and multiple objectives must be met simultaneously. MATLAB program MATCONT was employed to perform the bifurcation analysis. The MNLMPC calculations were carried out using the optimization language PYOMO, in conjunction with advanced global optimization solvers IPOPT and BARON. The bifurcation analysis revealed the existence of Hopf bifurcation points and a limit point. The MNLMC converged on the Utopian solution. The Hopf bifurcation point, which causes an undesirable limit cycle, is eliminated using an activation factor involving the tanh function. The limit point, which can lead to multiple steady-state solutions, is advantageous because it allows the Multiobjective nonlinear model predictive control calculations to converge to the Utopia point, representing the optimal solution in the model.