Direct Torque Control with Space Vector Modulation (DTC-SVM) of ...

DSP implementation of DTC-SVM control
7.2 Steady state behaviour
The experimental steady state no load operation at 25Hz stator frequency for
conventional ST-DTC (Fig. 4.10) and DTC-SVM (Fig. 5.46b) control is presented in
Fig. 7.5. The sampling time has been set at T = 200µ
s for DTC-SVM and T = 25µ
s for
hysteresis based ST-DTC method, respectively.
a)
s
s
b)
Figure 7.5. No load experimental steady state oscillograms at stator frequency 25Hz.
(a) ST-DTC for T = 25µ
s (b) DTC-SVM for T = 200µ
s.
s
From the top: line to line voltage, phase current, amplitude of stator flux, motor torque.
s
As we can observed from Fig. 7.5a the motor phase current characterized by high
current ripples. This is mainly because the inductances of the PMSM is smaller than an
equivalent power induction motor IM. In order to reduce the current ripples the
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