Efficiency Optimization; Efficiency Optimization For Induction Motors - Siemens SINAMICS S120 Function Manual

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6.15 Efficiency optimization

6.15 Efficiency optimization
6.15.1

Efficiency optimization for induction motors

Overview
Speed and torque are specified by the driven machine. As a consequence, the flux is the
remaining variable for optimizing the efficiency.
Function description
The efficiency of induction motors can be optimized using 2 different techniques. Both
techniques optimize the efficiency using the flux. It only makes sense to activate efficiency
optimization if the dynamic response requirements are low (e.g. pump and fan applications).
Benefits
For induction motors, efficiency optimization has the following advantages:
● Lower energy costs
● Lower motor temperature rise
● Reduced motor noise levels
Disadvantages
Disadvantages of efficiency optimization
● Longer acceleration times
● More significant speed dips for torque surges
● Lower dynamic response
The disadvantages are only relevant if the motor must respond with a high dynamic
performance. Also when that the efficiency optimization is active, the converter motor control
prevents the motor from stalling.
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Function Manual, 06/2019, 6SL3097-5AB00-0BP2
Drive functions