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.
<strong>Control</strong> methods <strong>of</strong> PM Synchronous motor<br />
y<br />
moment <strong>with</strong> active<br />
forward vector<br />
stops <strong>with</strong> zero<br />
vector<br />
Ψ s<br />
moment <strong>with</strong> active<br />
backward vector<br />
γ s<br />
δ Ψ<br />
Ψ =Ψ<br />
r<br />
PM<br />
x<br />
rotates<br />
continuously<br />
α<br />
stator<br />
Figure. 4.7 Stator flux vector Ψ<br />
s<br />
movement relative to rotor flux vector Ψ<br />
r<br />
=ΨPM<br />
under the<br />
influence <strong>of</strong> active and zero inverter voltage vectors.<br />
Therefore, it is possible control the torque angle δ Ψ<br />
across control stator flux vector<br />
position in respect to rotor flux vector produced by permanent magnet Ψ<br />
r<br />
=Ψ<br />
PM<br />
Ψ<br />
s<br />
, what<br />
further allows to have impact on control the electromagnetic torque in accordance <strong>with</strong><br />
following formula:<br />
M<br />
e<br />
3 Ψ sin<br />
2 s<br />
ΨPM<br />
δΨ Ψs<br />
( Lq<br />
−Ld)sin2δ<br />
Ψ<br />
= pb[ − ]<br />
(4.3)<br />
2 L<br />
2L L<br />
d d q<br />
Generally the <strong>DTC</strong> technique operate at constant stator flux amplitude<br />
Ψ<br />
s<br />
, what<br />
correspond to CSF operation, because <strong>of</strong> simple reference stator flux amplitude equal<br />
nominal value <strong>of</strong> permanent magnet. For <strong>DTC</strong> technique can be also apply all control<br />
strategies discussed in Chapter 2.<br />
Using the block generator for reference stator flux amplitude and electromagnetic<br />
torque as is shown in Fig 4.8. it is possible to draw the relationship between required<br />
Reference<br />
Flux<br />
Calculation<br />
reference<br />
flux<br />
Ψ s _ ref<br />
M<br />
e_<br />
ref<br />
reference<br />
torque<br />
reference<br />
torque<br />
M e _ ref<br />
Figure 4.8. Reference flux and torque generator block for <strong>DTC</strong> technique.<br />
reference flux and torque. His graphical illustration in Fig. 4.9 is presented.<br />
58