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CHAPTER 5: EMI MEASUREMENTS
I[dBµA]
I[dBµA]
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Limit for category L
0
0.1 1 10
Frequency [MHz]
Figure 5.10: CM current measurement for the Matrix converter output, motor side
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Limit for category L
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0.1 1 10
Frequency [MHz]
Figure 5.11: DM current measurement for the Matrix converter output, motor side
The same measurements have been performed to verify how the modulation index q
will affect the emissions. Fig. 5.12 reports the output current of the Matrix converter
for three different values of the modulation index: 0.6, 0.7 and 0.8; in the same figure it
is possible to verify that the current increases by roughly 10% at each step.
Fig. 5.13 and 5.14 show the emissions at the Matrix converter input, where it is clear
that there is no appreciable influence on the emissions by the value of the modulation
index.
In Fig. 5.15 and 5.16 it is possible to see the same effect on the output emissions: again
there is no influence, thus justifying the choice of an arbitrary value for the modulation
index that has been fixed at 0.7 for all the emission measurements performed in this
work.
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