Siemens CU240B-2 Operating Instructions

6.35 Efficiency optimization
Overview
The efficiency optimization reduces the motor losses as far as possible.
Efficiency optimization functions under the following preconditions:
● Operation with an induction motor
● Vector control is set in the inverter.
Active efficiency optimization has the following advantages:
● Lower energy costs
● Lower motor temperature rise
● Lower motor noise levels
Active efficiency optimization has the following disadvantage:
● Longer acceleration times and more significant speed dips during torque surges.
The disadvantage is only relevant when the motor must satisfy high requirements relating to
the dynamic performance. Even when efficiency optimization is active, the inverter closed-loop
motor control prevents the motor from stalling.
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Figure 6-57 Efficiency optimization by changing the motor flux
The three variables that the inverter can directly set, which define efficiency of an induction
motor, are speed, torque and flux.
However, in all applications, speed and torque are specified by the driven machine. As a
consequence, the remaining variable for the efficiency optimization is the flux.
The inverter has two different methods of optimizing the efficiency.
Efficiency optimization, method 2
Generally, energy efficiency optimization method 2 achieves a better efficiency than method 1.
Advanced commissioning
6.35 Efficiency optimization
Converter with the CU230P-2 Control Units
348 Operating Instructions, 09/2017, FW V4.7 SP9, A5E34257946B AE

Siemens CU240B-2 Specifications

General

Brand	Siemens
Model	CU240B-2
Category	Inverter
Language	English