Lenze 8400 StateLine - Manual (Page 144)

5 Motor control (MCTRL)
5.5 V/f characteristic control - energy-saving (VFCplusEco)
144
Lenze · 8400 StateLine · Reference manual · DMS 12.0 EN · 06/2014 · TD05/TD14
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5.5 V/f characteristic control - energy-saving (VFCplusEco)
This function extension is available from version 10.00.00!
With the energy-saving V/f characteristic control mode (VFCplusEco), the motor voltage of the
inverter is detected by means of a linear characteristic depending on the field frequency to be
created or the motor speed. Moreover, a cosϕ control and the resulting voltage reduction causes the
motor to be always operated in the optimum efficiency range (reduction of copper losses in the
asynchronous motor).
• Hence, these are the advantages of this motor control mode:
• Good robustness
• Easy parameter setting
• High energy efficiency (lower heating of the motor in partial load operational range)
• Same speed accuracy and maximum torques as with VFCplus
• Less noise generation of the motor with active voltage reduction
• Predestinated application areas of this motor control mode are materials handling technology
and pump and fan systems.
• This motor control mode serves to improve efficiency of standard asynchronous motors with
efficiency class IE1 (standard IEC 60034-30 2008) in the range 0 … M
efficiency_max
between
0 … 20 % (Ø 5 … 10 %).
• For asynchronous motors with energy efficiency class IE2 the potential for efficiency
improvement is reduced to approx. 0 ... 15 %.
• Description of M
efficiency_max
: Indicates the torque [%] of M
rated_motor
, where the motor has
the max. efficiency.)
• In case of asynchronous motors with a higher energy efficiency class (IE2 and IE3), the absolute
energy saving of the motor control mode is lower due to improved efficiency of the machine.
However, energy saving is still achieved in a higher load range.
• M
efficiency_max
is performance-related and listed in the following table for some power values
of the energy efficiency class IE1 and IE2:
M
Efficiency_max
(related to M
rated_motor
)
Power IE1 IE2
0.25 kW 75 %
0.75 kW 65 % 75 %
2.2 kW 55 % 85 %
7.5 kW 30 % 45 %
22 kW 23 %
45 kW 21 %