Application of vector and direct torque control methods to permanent magnet sysnchrnous motor

Permanent magnet synchronous motors have been used in many fields. They are seen attractive in some practical application because of they have certain good features such as high efficiency, flexible structure due to the magnets and high power density. Magnet prices are declining while energy prices are increasing in world. For this reason, life-long costs of PMSM?s are less than those of induction motors. There are a lot of high performance applications and research about PMSM?s.Vector and direct torque control methods are the basis of high-performance AC drive systems. They make principally torque control and they are commonly used in electrical drive systems.In this study, vector and direct torque control of PMSM are investigated. Speed control systems based on these methods are simulated and the results are evaluated.Vector control methods using hysteresis current control method and space vector modulation method are separately discussed.Stator flux can be estimated according to the voltage or the current model approaches in Direct Torque Control (DTC) method. These models were used in order to examine the structure of DTC system. Moreover, the DTC system based on the SVPWM method was also examined. Speed control systems based on the investigated methods are simulated in Matlab/Simulink program.Vector and direct torque control methods are compared in according to simulation results obtained from speed control system of PMSM.