This paper proposes a method of applying the Space Vector Modulation technique for Direct Torque Control (DTC) of a permanent magnet synchronous motor (PMSM) drive. By this method it is preserved the principle of the conventional DTC regarding the decoupled torque and flux control, while providing more flexibility for the inverter voltage utilization, in order to compensate the torque and flux errors in a smoother way than conventional DTC. For this purpose, a reference voltage space vector is calculated every sample time, using a simple algorithm, based on the torque error and the stator flux angle. Numerical simulations have been made to test the proposed method and results are presented.
- Direct Torque Control
- permanent magnet synchronous motor
- Space Vector Modulation
Fig. 1 Block diagram of the conventional DTC
EXPECTED SIMULATION RESULTS:
Fig. 2 Classic DTC, at 100 rpm
Fig. 3 Classic DTC, at 1000 rpm
Fig. 4 DTC with voltage control using the proposed method, at 100 rpm
Fig. 5 DTC with voltage control using the proposed method, at 1000 rpm
In this paper it was presented a method of utilisation of Space Vector Modulation for the Direct Torque Control of a PMSM. For this purpose, at every control sample time a reference voltage vector is calculated and applied to the inverter using SVM. To determine the reference voltage, a simple algorithm was proposed, based on the torque error and the flux phase angle.
The results show that a smooth steady state operation was obtained when using the proposed method. Moreover, a constant inverter switching frequency is ensured by using SVM.
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