Replacement Of Converters In Simovert A Range By Sinamics - Siemens SINAMICS G130 Engineering Manual

General Engineering Information for SINAMICS
Engineering Information
3.8.3

Replacement of converters in SIMOVERT A range by SINAMICS

Properties of the SIMOVERT A converter
SIMOVERT A converters are current-souce DC link converters and therefore capable of 4Q operation without
modification or upgrading. Both the rectifier and the motor-side inverter of converters in the SIMOVERT A range are
equipped with normal thyristors.
Drive with SIMOVERT A current-source DC link converter
The voltage rate-of-rise at the inverter output is very significantly lower than on PWM converters with IGBTs. As a
result, the voltage stress on the motor winding and the bearing currents in the motor bearings are very low.
Since line currents and motor currents have a very high harmonic content in drives with current-source DC link
converters, converters in the higher output power range are usually operating as a 12-pulse configuration at both the
line and the motor side. In this case, the line-side rectifier and motor-side inverter both consist of a 12-pulse parallel
connection. The motor is a 6-phase motor with two electrically isolated, 3-phase winding systems with a phase
displacement angle of 30 °el. between the two winding systems.
Properties of 1LA6, 1LA8 and 1LA1 motors operating on SIMOVERT A converters
·
The motors feature either standard rotor design or special low-leakage rotor design for SIMOVERT A:
These special rotors are found on 1LA6 motors of frame sizes 315L or higher, on 1LA8 motors designated
with the letters "QS" or "QT" in the order number, and on 1LA1 motors in general.
·
1LA1 motors can feature either a 3-phase winding design (for 6-pulse operation on SIMOVERT A), or a 6-
phase winding design with two separate 3-phase windings with a phase displacement angle of 30 °el.
between the winding systems (for 12-pulse operation on SIMOVERT A).
·
The insulation system on 1LA6 motors is comparable to the standard insulation on modern motors. This
also applies to 1LA8 motors as these were not equipped with special insulation for converter-fed operation
at 690 V until the SIMOVERT Masterdrives product range was launched. The insulation system on 1LA1
motors is comparable to the modern special insulation for converter-fed operation at 690 V (see chapter
"Motors").
·
Motors in the 1LA6 range are not fitted with an insulated bearing at the NDE (non-drive end). This also
applies in general to motors in the 1LA8 series as they were not equipped with insulated NDE bearings for
converter-fed operation until the SIMOVERT Masterdrives product range was launched. Due to their
higher frame sizes motors in the 1LA1 range are fitted with an insulated bearing at the NDE.
Replacement of SIMOVERT A converters by SINAMICS
It is not always possible to replace SIMOVERT A current-source DC link converters with voltage-source DC link
converters from the SINAMICS range. It is essential to analyze the existing drive constellation exactly for the
following reasons:
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