A new method research of fuzzy DTC based on full-order state observer for stator flux linkage

In this paper, permanent magnet synchronous motor is the controlled object. Aiming at the big torque and flux linkage ripple problem of traditional PMSM DTC system, fuzzy control concept was introduced. Simultaneously, the new system utilizes the full-order state observer to replace the integral part of the stator flux linkage observer in traditional direct torque control, and this method effectively reduces the dc drift, the integral error accumulation and other shortcomings. By the experimenting for the traditional PMSM DTC system with stator flux linkage integral observer and the PMSM fuzzy DTC system with full-order state observer that was designed in this paper, the results show the control performance of the new fuzzy DTC system is better than the one of traditional DTC system evidently. In other word, the stator flux linkage and torque ripple of new system are decreased significantly.