Shark -new motor design concept for energy saving- applied to - VBN

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Chapter 2 Linear analysis of the Shark switched Reluctance Motor
In order to highlight the dependence of the inductance gain on the number of Shark segments and
on their height, expression (2.8) may be rewritten based on the saw-toothed geometry illustrated in
Fig. 2.4 as follows:
k saw
Lsaw
L0
2
lshk
2
lshk
2
2
hshk
1
2 hshk
lshk
2
(2.9)
Now the influence of the length and height of the Shark profile can be studied separately. If, for
instance, the height of the Shark segment is held constant the inductance gain increases with
reduction of the Shark segment pitch. The variation is shown in Fig.2.9. On the other hand, if the
length of the Shark segment is held constant, then the inductance gain increases as the height of the
Shark segment increases as shown in Fig.2.9.
inductance gain = L saw /L 0
8
7
6
5
4
3
2
h shk /g=1
h shk /g=5
h shk /g=10
h shk /g=15
1
0 10 20
l /g
shk
30 40
Fig.2.9 Inductance gain for the saw-toothed air gap showing
the influence of the height and length of the Shark tooth
The change in the energy of the saw toothed air gap may be determined as:
energy gain = W saw / W 0
9
8
7
6
5
4
3
2
h shk /g=1
h shk /g=5
h shk /g=10
h shk /g=15
1
0 10 20
l /g
shk
30 40
Fig.2.10 Energy gain for the saw-toothed air gap showing
the influence of the height and length of the Shark tooth
a u
W saw Wsaw
Wsaw
(2.10)
a u
where: W saw and W saw are the energies of the saw toothed SRM in the aligned and unaligned
position respectively.
As mentioned in the previous section, the inductance in the unaligned rotor position, was assumed
to be equal for the Shark SRM and CSRM. Therefore, the energy in the unaligned position is also