Energy Saving Function - WEG CFW-11 Programming Manual

Description:
It is the actuation level of the DC link voltage limitation function for the V/f mode.
Setting of P0151 value:
a) The P0151 factory setting leaves inactive the DC link voltage limitation function for the V/f mode. In
order to activate it, one must reduce the value of P0151 as suggested in the
Inverter
220/230 V
V
nom
P0296 0
P0151 375 V
b) In case DC link overvoltage (F022) keeps happening during the deceleration, reduce the value of
P0151 gradually or increase the deceleration ramp time (P0101 and/or P0103).
c) If the supply line is permanently at a voltage level that results in a DC link voltage higher than the
P0151 setting, it will not be possible to decelerate the motor. In this case, reduce the line voltage or
increase the value of the P0151 setting.
d) If, even with the procedures above, it is not possible to decelerate the motor in the necessary time, use
the dynamic braking (Refer to the
P0152 – DC Link Voltage Regulator Proportional Gain
Adjustable 0.00 to 9.99
Range:
Properties: V/f and VVW
Access groups 01 PARAMETER GROUPS
via HMI:
Description:
It defines the DC Link Voltage Regulator proportional gain (refer to the
P0152 multiplies the DC link voltage error, i.e., Error = actual DC link voltage – (P0151), and it is normally used
to prevent overvoltage in applications with eccentric loads.

9.5 ENERGY SAVING FUNCTION

The efficiency of an induction motor is defined as being the ratio between the output mechanical power and
the input power. By definition, mechanical power is the product of torque on the motor shaft by the rotor speed.
The input electric power is the sum of the output mechanical power and the total losses of the motor. Therefore,
the efficiency can be improved by reducing the input electric power with the reduction of the total motor losses.
The optimization of the performance is linked to the reduction of the motor losses. Induction motors are normally
sized to operate with constant voltage and frequency, and an optimized efficiency of approximately 75 % of the
rated load. Thus, when the motor is operating with loads below 75 %, its efficiency is jeopardized. In view of
that, an efficient way to obtain the optimal performance of the motor, in cases of low loads, is to use a proper
control method to adjust the voltage or frequency values of the motor.
Table 9.2 - Recommended actuation levels for the DC link regulation
380 V 400/415 V 440/460 V
1 2 3
618 V 675 V 748 V
Chapter 14 DYNAMIC BRAKING on page
27 V/f DC Volt. Limit.
Table 9.2 on page
480 V 500/525 V 550/575 V
4 5 6
780 V 893 V 972 V
14-1).
Factory
Setting:
Figure 9.12 on page
Scalar Control (V/f)
9-13.
600 V 660/690 V
7 8
972 V 1174 V
1.50
9-11).
9-13
9