Research On The Direct Torque Control For Permanent Magnet Synchronous Motors Using Space Vector Modulation

The theory background and situation of the Direct Torque Control (DTC) are introduced ,dominance and disadvantage are also mentioned in this paper .In order to improve the motor performance ,the Direct Torque Control based on space vector modulation is proposed for synchronous motor and others with low stator inductance.Direct Torque Control using Space Vector Modulation (SVM-DTC) scheme is discussed and the detailed designed ,including space vector choosing and modulating , to overcome the control difficulties coming with the characteristic of low inductance. Comparing with the basic DTC, the simulation results confirm the feasibility and good performance of this strategy. In order to reduce the torque error in dynamic state resulted from the nonlinear relationship between the torque and torque angle, a proportional-plus-integral (PI) torque controller with variable proportion is presented to ensure exact and quick control of torque in dynamic state. Based on the theory and the simulation ,the experimental results verify the feasibility of the SVM-DTC .