| Abstract |
Analytical model of 3 phase converter traction
drive with 2 drive unit supplied from 3 kV DC line is
analyzed. The harmonics generated by the converter system
injected into the supplying line are determined in analytical
way. The calculation method is based at the generalized
theory of static converter described in the literature
[3,4,5,6,7,8]. The calculation results achieved in that way are
compared with the measuring made in traction drive
realized in the praxis. The generation of harmonic in
traction drive system, independent of the complexity of the
system, can be describe in closed analytical way. The
analytical description allows systematic investigation of the
effects connected with the propagation of the harmonics in
the drive system and the environment of the system. The
harmonics of the system can be divided into three groups of
harmonics. To the first group belongs harmonics depending
on the internal properties of the substation, its symmetry
and the accuracy of the substation transformer. The
harmonic of this group are positioned on the harmonic
raster of the supplying network. The second group of
harmonic is generated by the 3 phase converter traction
drive. Harmonics of this group are depending on the
operating point of the traction converter, (the stator
frequency of the traction motor) and are sliding along the
harmonic raster of line frequency. The third group of
harmonics is generated trough the convolution of the both
previous type of harmonics. |
