Fuzzy Logic-Based Direct Torque Control of Permanent Magnetic Synchronous Motor

In order to improve the system stability and raise the response speed, a new control scheme, fuzzy logic-based direct torque control, for a permanent magnet synchronous motor (PMSM) was put forward. In this scheme, zero voltage space vectors are introduced to simplify fuzzy control rulers. Simulation results show that compared with the common direct torque control, the flux locus of the fuzzy direct torque control is more approximatively a circle, and the rotational speed can reach up to a stable value quickly. Subjected to an external disturbance, the torque for the proposed scheme can change smoothly and reach to a new stable value. Furthermore, the high frequency components of the stable current decrease greatly.