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 ...
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<strong>Direct</strong> <strong>Torque</strong> <strong>Control</strong> <strong>with</strong> <strong>Space</strong> <strong>Vector</strong> <strong>Modulation</strong><br />
M e _ ref<br />
U sy<br />
C () M<br />
s GM<br />
() s<br />
M e<br />
Figure 5.35. Block diagram <strong>of</strong> torque control loop in s-domain.<br />
The transfer function <strong>of</strong> torque control loop is obtained as:<br />
G<br />
M _ closed<br />
() s<br />
M () s C () s G () s<br />
e_<br />
ref M M<br />
= = (5.73)<br />
M<br />
e() s 1 + CM() z GM()<br />
s<br />
Substituting in equation (5.73) transfer function for CM<br />
( s)<br />
-Eq.5.28 and GM<br />
( s)<br />
- Eq.5.72 we<br />
may calculate:<br />
KiM<br />
AMKpM( s+<br />
)<br />
K<br />
pM<br />
GM<br />
_ closed()<br />
s = =<br />
2<br />
s + ( B + K A ) s+ C + K A<br />
M pM M M iM M<br />
(5.74)<br />
Discrete design<br />
z −1<br />
Using backward difference method for discretization process ( s = ) the transfer function<br />
Tz<br />
for discrete PI controller is expressed as:<br />
s<br />
K<br />
pM<br />
( z − )<br />
Tz<br />
KpM<br />
+ K<br />
s<br />
iM<br />
CM( z) = KpM(1 + ) = ( KpM + KiM)<br />
T ( z−1) ( z−1)<br />
iM<br />
(5.75)<br />
Where:<br />
K<br />
iM<br />
K<br />
pM<br />
= Ts<br />
- integration gain;<br />
s<br />
TiM<br />
T - sampling time<br />
101