Nonlinear speed control for PMSM using mixed H2/H∞ state output feedback control

For the characteristic of the Performance of Permanent Magnet Synchronous Motor (PMSM) used in direct drive applications suffering from the effect of load disturbances and the model parameter uncertainties. Therefore, based on linear matrix inequality(LMI), a multi-objective mixed H₂/H_∞ static output feedback controller of the PMSM system is designed to replace the traditional PI regulator, which makes all poles of the closed-loop system be located in a prescribed LMI region D to achieve pole placement. The multi-objective controller considers the pole location of the closed-loop system and two important robust performance objects (H₂ and H_∞ norm) simultaneously, which does not only guarantee rapidity and stability of the system, but is better in robustness against external and internal disturbances, and the contradiction between rapidity and robustness are solved to satisfy the direct drive system. Simulation and experimental results both show the robustness and rapidity for PMSM used in direct drive system.