Siemens SINAMICS G120C User Manual

8.31 E󹪟ciency optimization
Overview
The e󹪟ciency optimization reduces the motor losses as far as possible.
Active e󹪟ciency optimization has the following advantages:
• Lower energy costs
• Lower motor temperature rise
• Lower motor noise levels
Active e󹪟ciency optimization has the following disadvantage:
• Longer acceleration times and more signi󹪝cant speed dips during torque surges.
The disadvantage is only relevant when the motor must satisfy high requirements relating
to the dynamic performance. Even when e󹪟ciency optimization is active, the converter
closed-loop motor control prevents the motor from stalling.
Requirement
E󹪟ciency optimization functions under the following preconditions:
• Operation with an induction motor
• Vector control is set in the converter.
Function description
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Figure8-75 E󹪟ciency optimization by changing the motor 󹪞ux
The three variables that the converter can directly set, which de󹪝ne e󹪟ciency of an induction
motor, are speed, torque and 󹪞ux.
However, in all applications, speed and torque are speci󹪝ed by the driven machine. As a
consequence, the remaining variable for the e󹪟ciency optimization is the 󹪞ux.
The converter has two di󹪜erent methods of optimizing the e󹪟ciency.
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Advanced commissioning
8.31E󹪟ciency optimization
SINAMICS G120C Converters
352 Operating Instructions, 02/2023, FW V4.7 SP14, A5E34263257B AK

Siemens SINAMICS G120C Specifications

General

Brand	Siemens
Model	SINAMICS G120C
Category	Inverter
Language	English