Installation and commissioning
DIGIDRIVE
Variable speed drive
Réf. 3218 GB - 4.33 / d - 02.02
LEROY-SOMER
27
3.5 - Electrical and electromagnetic
phenomena
3.5.1 - General
The power structure of variable speed
drives leads to the occurrence of two types
of phenomenon:
- low frequency harmonic feedback on the
mains power supply
- emission of radio frequency signals (RFI)
These are independent phenomena.
They have different consequences on
the electrical environment.
3.5.2 - Low frequency harmonics
The rectifier, at the head of the variable
speed drive, draws on the capacitors and
generates a non-sinusoidal AC line current.
This current carries harmonics with odd
numbers (3, 5, 7 etc for single-phase drives
and 5, 7, 11, 13 etc for three-phase drives).
The amplitude of these harmonics depends
on the impedances upstream of the rectifier
(line impedance plus any additional
chokes) and downstream of the rectifier
(DC bus choke inside the drive, if fitted).
The higher the value of these impedances,
the more the amplitude of the current
harmonics is reduced.
The addition of further line chokes reduces
the amplitude of the mains supply current
harmonics (especially for drives not fitted
with a DC bus choke), but also attenuates
transient interference between the mains
and the drive.
These line chokes are compulsory for 0.5M
to 1.2M ratings, for conformity with
standard EN 61000-3-2 "Limiting emissions
of harmonic currents" in the domestic
environment, and are strongly
recommended for other ratings in the
following cases:
- mains power supply transformer power
above 200 kVA
- line short-circuit current above 5 kVA
- bank of capacitors for reading the power
factor connected on the mains
- drives with high-power thyristors supplied
by the same mains supply (especially if
they are not fitted with line chokes)
- D.O.L. induction motors on the mains
supply causing transient voltage drops of
more than 20%.
3.5.3 - Radio frequency interference:
Immunity
3.5.3.1 - General
The immunity level of a device is defined by
its ability to operate in an environment
which is polluted by external elements or by
its electrical connections.
3.5.3.2 - Standards
Each device must undergo a series of
standard tests (European standards) and
meet a minimum requirement in order to be
declared as compliant with the generic
industrial (EN 50082-2) and domestic (EN
50082-1) standards.
DIGIDRIVE ratings Mains Mains chokes
0.5M to 1.2M 1-ph
(16mH/4.5A)
Consult
LEROY-SOMER
1.5M, 1.5M/TL
1-ph
(1mH/7.3A)
and Consult
2M/TL
LEROY-SOMER
2.5M/TL
1-ph
(0.5mH/19A)
and Consult
3.5M/TL
LEROY-SOMER
1.5M/TL to 2.5M/
3-ph
9 ST 2.5
(2.5mH/9A)
and
1.5T to 3.5T
3.5M/TL
3-ph
16 ST 1.5
(1.5mH/16A)
and
4.5T to 11T
5.5TL to 11TL
3-ph
25 ST 1
(1mH/25A)
and
16T and 22T
27T 3-ph
38 ST 0.65
(38A / 0.65mH)
33T and 40T 3-ph
60 ST 0.4
(60A / 0.4mH)
50T 3-ph
90 ST 0.28
(90A / 0.65mH)
To Next Page
Loading...
Need help?
General
