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time of winding insulation, break the motor insulation easily and cause wide-
band electromagnetic interference. Thus, the techniques to reduce the CMV or
to limit it within certain bounds are of crucial importance for adjustable speed
drive system which is fed by two-level or multilevel inverter.
To make sure the TSMC get maximal DC voltage utilization and minimal out-
put voltage harmonics, a novel space vector pulse width modulation(SVPWM)
algorithm using four nearest space vectors is first discussed. A suitable SVPWM
algorithm is then developed to reduce the common-mode voltage. The proposed
modulation techniques are further supported by simulation.
2 Three-to-Five Phase TSMC Model and Its Inverter
Stage Space Voltage Vector
Fig.1 illustrates the modified matrix converter topology presented in this pa-
per. The equivalent transformation matrix from the five-phase variables to the
synchronously rotating
d
1
−
q
1
−
d
3
−
q
3
axes variables can be defined as
Fig. 1.
Three-to-five phase TSMC model
⎡
⎤
cos(
θ
0
) s(
θ
1
) s(
θ
2
) s(
θ
3
) s(
θ
4
)
−
sin(
θ
0
)
−
sin(
θ
1
)
−
sin(
θ
2
)
−
sin(
θ
3
)
−
sin(
θ
4
)
cos(3
θ
0
)
θ
1
)
θ
2
)
θ
3
)
θ
4
)
−
⎣
⎦
T
(
θ
)=
(1)
sin(3
θ
0
)
−
sin(3
θ
1
)
−
sin(3
θ
2
)
−
sin(3
θ
3
)
−
sin(3
θ
4
)
1
2
1
2
1
2
1
2
1
2
iα
;
θ
r
denotes the rotor angle;
α
=
2
5
. Since a five-phase IMC
is under consideration, one deals here with a five-dimensional space. Hence two
space vectors have to be defined, each of which will describe space vectors in one
two-dimensional subspace (and)[9]. The third subspace is single-dimensional and
where
θ
i
=
θ
r
−
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