Siemens SINAMICS G130 Engineering Manual page 523

The diagram below shows the basic curve of the thermal torque-limit characteristic of SIMOTICS FD motors in
converter-fed operation illustrated by the example of 1LM1 self-ventilated motors (the characteristics for all other
motor types can be found in Catalog D 81.8). All thermal limit characteristics apply to operation on converters that are
operating with pulse frequencies of < 2.5 kHz under the condition that they always switch over from space vector
modulation to optimized pulse patterns (P1802 = 19) for thermal reasons at a speed corresponding to approximately
87 % of rated speed.
Modulation systems and thermal torque limit illustrated by
example of self-ventilated 1LM1 SIMOTICS FD motors
If the application requires the converter to operate only with space vector modulation at all times (e.g. due to very
high requirements with respect to torque accuracy and/or dynamic response), the converter pulse frequency must be
increased (taking into account the relevant current derating factor of the converter) to at least 2.5 kHz either generally
or at the latest when the motor speed reaches around 87 % of rated speed in cases where the thermal limit
characteristic needs to be fully utilized at speeds above approximately 87 % of rated speed. As an alternative, the
rated motor output can be reduced as indicated below as a function of the pulse frequency.
• Space vector modulation with pulse frequency 1.25 kHz:
• Space vector modulation with pulse frequency 2.00 kHz:
• Space vector modulation with pulse frequency 2.50 kHz:
The optimized pulse patterns for SIMOTICS FD motors are always activated on SINAMICS converters when
• parameter p0500 (technology application) is set to "1" (pumps and fans),
• parameter p0300 (motor type selection) is set to "14" (SIMOTICS FD), and
• parameter p1802 (modulator mode) is set to "19" (optimized pulse patterns).
With SINAMICS G converters on which parameter p0500 (technology application) is automatically preset to "1"
(pumps and fans), the only parameter to be assigned at the commissioning stage is parameter p0300 (motor type
selection) and this must be set to "14" (SIMOTICS FD). Parameter p1802 (modulator mode) is then automatically set
to "19" (optimized pulse patterns).
With SINAMICS S converters on which parameter p0500 (technology application) is automatically preset to "0"
(standard drive VECTOR), parameter p1802 (modulator mode) is set to "4" (space vector modulation SVM without
overmodulation) irrespective of the setting of parameter p0300 (motor type selection). For applications with very high
sophisticated control requirements such as coordinated multi-motor drives (strip finishing lines, paper-making
machines and foil-drawing machines) or single drives which demand precise torque accuracy or excellent dynamic
response, this setting is generally essential for technological reasons which means that the operation of SINAMICS S
converters with optimized pulse patterns is not advisable. For applications of this kind, therefore, the pulse frequency
of the converter must either be increased to at least 2.5 kHz (taking into account the relevant current derating factor)
or the rated motor output must be reduced as a function of the pulse frequency, according to the description given
above.
For applications that do not demand such a high level of control performance, the parameter settings described
above for SINAMICS S converters can be manually adjusted at the commissioning stage to match the equivalent
parameter settings for SINAMICS G converters. In this case, the SINAMICS S converters will also operate with
optimized pulse patterns for SIMOTICS FD (p1802 = 19) which means that it is not necessary to increase the
converter pulse frequency or reduce the rated motor output.
In the case of SIMOTICS FD motors with rated speeds of > 3000 rpm or rated frequencies of > 100 Hz, please note
that the converter pulse frequency must be raised above the factory setting f
required output frequencies. When increasing the pulse frequency, please take the relevant current derating factors
into account.
Engineering Information
Motor derating factor 0.85
Motor derating factor 0.95
Motor derating factor 1.00
Pulse
SINAMICS Engineering Manual – November 2015
Motors
= 1.25 kHz in order to obtain the
523/528
Ó Siemens AG