RX62T YROTATE-IT-RX62T Motor Control Kit
UM-YROTATE-IT-RX62T Rev.1.00
Page 18 of 51
Jan 15, 2014
dt
d
i
R
v
dt
d
i
R
v
dt
d
i
R
v
c
c
S
c
b
b
S
b
a
a
S
a
λ
λ
λ
+
=
+
=
+
=
-
λ
i
is the magnetic flux linkage with the i-th stator winding
- R
S
is the stator phase resistance (the resistance of one of the stator windings)
The magnetic flux linkages
λ
i
are composed by two items, one due to the stator currents, one to the permanent
magnets.
The permanent magnet creates a magnetic field that is constant in amplitude and fixed in position in respect to the
rotor. This magnetic field can be represented by vector
Λ
m
whose position in respect to the stator is determined by
the angle
ϑ
between the vector direction and the stator reference frame.
The contribution of the permanent magnets in the flux linkages depends on the relative position of the rotor and the
stator represented by the mechanical-electric angle
ϑ
.
It is, in every axis, the projection of the constant flux vector
Λ
m
in the direction of the axis:
)
3
4
cos(
)
3
2
cos(
)
cos(
π
ϑ
λ
π
ϑ
λ
ϑ
λ
−
Λ
+
=
−
Λ
+
=
Λ
+
=
m
c
c
m
b
b
m
a
a
Li
Li
Li
ϑ
Λ
m
a
a’
b
c
c’
b’
a axis
b axis
c axis
Real axes (a, b, c) and equivalent ones (
α
,
β
); a fixed amplitude vector can be completely determined by its
position respect the (
α
,
β
) system (angle
ϑ
)
α
α
’
α
axis
β
’
β
’
β
axis
