Siemens SINAMICS G130 Engineering Manual page 522

Motors
Engineering Information
Low noise emissions
The motor noise emissions are minimized thanks to the harmonized drive components, i.e. the SIMOTICS FD motor
and a SINAMICS converter. The noise emissions are particularly low in the speed range around the rated speed. The
reduction in noise level is based two measures:
•
The innovative electrical and mechanical design of the SIMOTICS FD motors.
(This measure reduces noise emissions over the entire speed range).
•
By pulse patterns of the SINAMICS converter that have been specially developed and optimized for
operation with SIMOTICS FD motors. (This measure reduces noise emissions mainly in the upper speed
range around the rated speed).
Since SINAMICS converters utilize space vector modulation at a low depth of modulation (low output voltage), i.e. at
low speed, and do not start to use optimized pulse patterns until approximately 87 % of the maximum modulation
depth (output voltage) is reached, i.e. at higher speeds, the following points need to be taken into account in the
dimensioning and selection of a noise-optimized drive system:
•
The rated voltage of the motor must be selected such that it will match the maximum achievable output
voltage of the converter taking in account the line voltage and the type of Infeed of the SINAMICS converter.
•
The rated speed of the motor must must be selected such that it will be lower than or equal to the predicted
operating speed(s) for the relevant application.
•
The application must allow operation with optimized pulse patterns and the converter must be
parameterized in such a way that it will operate with the optimized pulse patterns in the upper speed range
(for further details, please refer to section "Temperatue rise / efficiency" below).
By implementing these measures, it is possible to ensure that the converter will operate with optimized pulse patterns
from about 87 % of rated speed due to the high depth of modulation (output voltage) required and that the benefits of
the new SIMOTICS FD motor design and the advantages of the new optimized pulse patterns for SINAMICS
converters will be utilized to minimize the noise emissions of the SIMOTICS FD motor.
The following diagrams show the basic curves of the sound pressure level of 1LM1 and 1LL1 self-ventilated motors,
and those of 1LQ1, 1LP1, 1LH1 and 1LN1 forced-air cooled and water-cooled motors if these are dimensioned
according to the criteria specified above.
Schematic diagram of sound pressure level 1LM1, 1LL1
By utilizing optimized pulse patterns, it is possible to reduce noise emissions, particularly at speeds around the rated
speed (rated range).
In self-ventilated motors (1LM1, 1LL1), the aerodynamic noise generated by the built-in fan dominates with increasing
speed above the rated range. For drives of this type, the high operating speeds should, where possible, also be
within the rated speed range (rated range).
In order to achieve a low-noise design of drives with constant torque (mainly with motors of type 1LQ1, 1LP1, 1LH1
and 1LN1), it is important to consider when dimensioning and selecting drive components that even the low operating
speeds should be as close as possible to the rated speed range (rated range), i.e. to the range in which the converter
will operate with optimized pulse patterns. This can often be achieved through a favorable choice of rated speed.
Temperature rise / efficiency
SIMOTICS FD motors are designed to operate with the optimized pulse patterns of SINAMICS converters for the
ultimate purpose of minimizing system losses and thus achieving an optimum degree of system efficiency by the
combination of the SIMOTICS FD motor and the SINAMICS converter. These motors can therefore operate without
derating on SINAMICS converters using optimized pulse patterns (p1802 = 19) at pulse frequency settings of
1.25 kHz and higher. A pulse frequency of 1.25 kHz is the factory (default) setting for most of the SINAMICS
converters described in this engineering manual.
SINAMICS Engineering Manual – November 2015
522/528
Ó Siemens AG
Schematic diagram of sound pressure level 1LQ1, 1LP1,
1LH1, 1LN1