Direct Torque Control with Space Vector Modulation (DTC-SVM) of ...

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