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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Modeling and control modes <strong>of</strong> PM synchronous motor drives<br />
Substituting to above equations the following expressions for complex vectors<br />
U U jU<br />
sxy<br />
=<br />
sx<br />
+<br />
sy, Isxy<br />
Isx jIsy<br />
= + , Ψ =Ψ<br />
s<br />
and splitting into real and imaginary parts<br />
sxy<br />
one can obtain the scalar form <strong>of</strong> the machine equations in stationary x,<br />
y reference<br />
frame:<br />
U<br />
dΨ<br />
dt<br />
s<br />
sx<br />
= Rs Isx<br />
+ (2.27a)<br />
U = R I +ΩΨ<br />
Ψ (2.27b)<br />
sy s sy s<br />
s<br />
1 1<br />
Ψ<br />
s<br />
= [( Ld + Lq) −( Lq − Ld)cos 2 δΨ ] Isx<br />
+ ( Lq − Ld)sin 2δΨIsy<br />
+Ψ<br />
PM<br />
cosδΨ<br />
2 2<br />
(2.28a)<br />
1 1<br />
0 = ( Lq − Ld)sin2 δΨIsx<br />
+ [( Ld + Lq) + ( Lq −Ld)cos2 δΨ] Isy<br />
−Ψ<br />
PM<br />
sinδΨ<br />
2 2<br />
(2.28b)<br />
The current-flux equations can be expressed also in simplest form as:<br />
2 2<br />
s<br />
( Ld cos δΨ Lqsin δΨ) Isx<br />
( Lq Ld)sinδΨcosnδΨIsy<br />
PM<br />
cosδΨ<br />
Ψ = + + − +Ψ (2.29a)<br />
2 2<br />
q d<br />
δΨ δΨ sx d<br />
δΨ q<br />
δΨ sy PM<br />
δΨ<br />
0 ( L L )sin cos I ( L sin L cos ) I sin<br />
= − + + −Ψ (2.29b)<br />
Rotor flux fixed system ( dq) ,<br />
In order to take advantage <strong>of</strong> the set <strong>of</strong> equations (2.19) and (2.20) in rotating coordinate<br />
system, one assumes that the coordinate system rotates <strong>with</strong> the rotor flux angular speed<br />
Ω<br />
K<br />
= pbΩ m<br />
and θK = pbγm = θr<br />
d Ψ<br />
U<br />
sdq<br />
R I jp<br />
dt<br />
sdq<br />
s sdq<br />
b m<br />
= + + Ω Ψ (2.30)<br />
sdq<br />
Ld + Lq Lq −Ld<br />
∗<br />
Ψ<br />
sdq<br />
= ( ) Isdq − ( ) Isdq<br />
+Ψ<br />
PM<br />
(2.31)<br />
2 2<br />
Substituting the following expressions for complex vectors U = Usd + jUsq,<br />
I I jI<br />
sdq<br />
=<br />
sd<br />
+<br />
sq, sdq sd<br />
j<br />
sq<br />
Ψ =Ψ + Ψ to (2.30) and (2.31), and splitting for real and<br />
imaginary parts the scalar form <strong>of</strong> the machine equations in rotational fixed reference<br />
frame can be obtained:<br />
dΨ<br />
sd<br />
Usd = Rs Isd + − pbΩmΨ sq<br />
(2.32a)<br />
dt<br />
sdq<br />
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