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 />
The references <strong>of</strong> stator flux components (see Fig. 5.3) are compared <strong>with</strong> estimated value:<br />
Ψ<br />
Ψ<br />
= Ψ<br />
cos θ ,<br />
sα<br />
s Ψs<br />
= Ψ<br />
sin θ ,<br />
sβ<br />
s Ψs<br />
The command voltage can be calculated from flux errors in<br />
(5.5)<br />
α, β coordinate system as<br />
follows:<br />
U<br />
U<br />
∆Ψ<br />
= + R I<br />
sα<br />
sα<br />
_ ref s sα<br />
Ts<br />
∆Ψ<br />
= + R I<br />
sβ<br />
sβ<br />
_ ref s sβ<br />
Ts<br />
(5.6)<br />
Where: T<br />
s<br />
is sampling time,<br />
∆Ψ = Ψ − Ψ , ∆Ψ =Ψ<br />
_<br />
−Ψ .<br />
sα sα_<br />
ref sα<br />
sβ sβ ref sβ<br />
The presented bellow design methodology for flux and torque control loops based on the<br />
approach presented in literature [11,43].<br />
5.2.1 Digital flux control loop<br />
The flux control loop is based on the voltage equations <strong>of</strong> PMSM machine in stator<br />
coordinates.<br />
U<br />
U<br />
dΨ<br />
dt<br />
sα<br />
sα<br />
= RsIsα<br />
+ (5.7a)<br />
dΨ<br />
sβ<br />
sβ<br />
= RsIsβ<br />
+ (5.7b)<br />
dt<br />
Using Laplace transformation the above equations can be written as:<br />
U = sΨ + R I<br />
(5.8a)<br />
sα sα s sα<br />
U = sΨ + R I<br />
(5.8b)<br />
sβ sβ s sβ<br />
It corresponds to flux model <strong>of</strong> PMSM machine in α,<br />
β system presented in Fig. 5.4.<br />
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