Direct Torque Control with Space Vector Modulation (DTC-SVM) of ...
Direct Torque Control with Space Vector Modulation (DTC-SVM) of ...
Direct Torque Control with Space Vector Modulation (DTC-SVM) of ...
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Voltage source PWM inverter for PMSM supply<br />
rectifier by fully controllable active rectifier [8] (see Fig. 3.3), which guaranties<br />
following futures:<br />
• power flow from AC/DC or DC/AC side (there is no need <strong>of</strong> break resistor ),<br />
• significant reduction <strong>of</strong> phase current THD,<br />
• unity power factor (phase voltage is in phase <strong>with</strong> current),<br />
• reduction <strong>of</strong> DC link capacitor,<br />
• controllable DC link voltage.<br />
Three-phase<br />
grid<br />
Active<br />
Rectifier<br />
DC link<br />
filter<br />
Inverter<br />
AC motor<br />
Choke<br />
Fig. 3.3 Modern AC/DC/AC converter topology <strong>of</strong> adjustable speed drives.<br />
In the next part <strong>of</strong> this thesis the author will be focus on voltage source inverter.<br />
3.2 Voltage source inverter (VSI)<br />
The made constant DC voltage by rectifier is delivered the to the input <strong>of</strong> inverter (Fig.<br />
3.4), which thanks to controlled transistor switches, converts this voltage to three-phase<br />
AC voltage signal <strong>with</strong> wide range variable voltage amplitude and frequency [3].<br />
Voltage Source Inverter<br />
C F<br />
T 1<br />
D 7<br />
T 3<br />
D 9<br />
T 5<br />
D 11<br />
U DC<br />
O<br />
C F<br />
T 2<br />
D 8<br />
T 4<br />
D 10<br />
T 6<br />
D 12<br />
A B C<br />
U<br />
sAN<br />
U<br />
sBN<br />
U<br />
sCN<br />
N<br />
Three-phase motor windings<br />
Figure 3.4 Basic scheme <strong>of</strong> voltage source inverter circuit.<br />
35