Permissible Harmonics On The Supply Voltage - Siemens SINAMICS G130 Engineering Manual

A speed encoder can be used to make the flying restart process slightly faster than it is in encoderless operation.
This is because the current motor speed is immediately available thanks to the speed encoder and does not need to
be searched as it would in encoderless operation.
Flying restart of an asynchronous motor with speed encoder
A very fast flying restart can be achieved by installing a VSM10 Voltage Sensing Module at the inverter output. This
module measures the remanence voltage of the asynchronous motor. As a result, the degree of magnetization and
the speed of the motor are already known so that it is unnecessary to de-magnetize the motor or search the current
speed. The motor can be re-magnetized immediately and then accelerated.
The automatic restart and flying restart functions are implemented as standard in the converter firmware and can be
activated by parameterization if necessary.
For further information, please refer to the function manual "SINAMICS S120 Drive Functions".
1.2.10

Permissible harmonics on the supply voltage

SINAMICS converters and the corresponding line-side system components (line reactors, Line Harmonics Filter and
line filters) are designed for being connected to supplies with a continuous level of voltage harmonics, according to
EN 61000-2-4, Class 3. In the short-term (< 15 s within a time period of 2.5 min) a level of 1.5 times the continuous
level is permissible.
Harmonic Number
h
5
7
11
13
17
17 < h ≤ 49
Compatibility level for harmonics, according to EN 61000-2-4
– harmonic contents of the voltage V, odd harmonics, no multiples of 3
Total Harmonic Distortion factor
THD(V)
Compatibility levels for the Total Harmonic Distortion factor of the Voltage THD(V) according to EN 61000-2-4
That means that no voltage harmonics higher than those given in the table under Class 3 may appear at the
connection point for SINAMICS units. This includes harmonics produced by the units themselves. This must be
guaranteed by means of correct engineering. If necessary, Line Harmonics Filters, 12-pulse solutions or Active
Infeeds may be used to stay within the limits of Class 3.
Otherwise, components in the converter itself or the corresponding line-side components may be thermically
overloaded or error functions may occur in the converter.
Further information can be found in the section "Harmonic effects on the supply system", under the subsection
"Standards and permissible harmonics".
Fundamental Principles and System Description
Class 1
V
h
%
3
3
3
3
2
2.27 x (17/h) – 0.27
Class 1
5 %
SINAMICS Engineering Manual – November 2015
Engineering Information
Class 2
V
h
%
6
5
3.5
3
2
2.27 x (17/h) – 0.27 4.5 x (17/h) – 0.5
Class 2
8 %
Ó Siemens AG
Class 3
V
h
%
8
7
5
4.5
4
Class 3
10 %
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