Regeneration Avoidance Function (Pr.665, Pr.882, Pr.883, Pr.885, Pr.886) - Mitsubishi Electric FR-E700EX Instruction Manual

Special operation and speed control

4.19.2 Regeneration avoidance function (Pr.665, Pr.882, Pr.883, Pr.885, Pr.886)

This function detects a regeneration status and increases the speed to avoid the regenerative status.
 Possible to avoid regeneration by automatically increasing the speed and continue operation if the fan happens to
rotate faster than the set speed due to the effect of another fan in the same duct.
Parameter
number
Regeneration avoidance
882
operation selection
Regeneration avoidance
883
operation level
Regeneration avoidance
885 compensation speed limit
value
Regeneration avoidance
886
voltage gain
Regeneration avoidance
665
speed gain
The above parameters can be set when Pr.160 Extended function display selection = "0". (Refer to page 182)

When an S-PM geared motor is used, the maximum setting value differs depending on the drive unit capacity. (0.2 to 2.2K: 1350 r/min, 3.7K: 900 r/min)
(1) What is regeneration avoidance function? (Pr.882, Pr.883)
 When the regeneration load is large, the DC bus voltage rises and an overvoltage fault (E. OV) may occur. When this
bus voltage rise is detected and the bus voltage level reaches or exceeds Pr.883, increasing the speed avoids the
regeneration status.
 The regeneration avoidance function is always ON when "1" is set in Pr.882 and activated only during a constant speed
when "2" is set in Pr.882.
Regeneration avoidance operation example
for acceleration
Pr.883
During regeneration
avoidance function operation
Regeneration avoidance
operation example for deceleration
Pr.883
During regeneration
avoidance function operation
242
Initial
Name
value
0
400VDC
180r/min
100%
100%
Time
Time
Time
Time
Setting
range
0 Regeneration avoidance function invalid
1 Regeneration avoidance function is always valid
Regeneration avoidance function is valid only during a
2
constant speed operation
Bus voltage level at which regeneration avoidance
operates. When he bus voltage level is set to low,
overvoltage error will be less apt to occur. However, the
300 to 800V
actual deceleration time increases.
The set value must be higher than the "power supply
voltage 2
0 to 540r/min Limit value of speed which rises at activation of
1
regeneration avoidance function.
9999 Speed limit invalid
Responsiveness at activation of regeneration avoidance.
0 to 200%
A larger setting will improve responsiveness to the bus
voltage change. However, the rotation speed could become
unstable.
0 to 200%
When vibration is not suppressed by decreasing the Pr.886
setting, Pr.665 set a smaller value in Pr.665.
Regeneration avoidance operation example
for constant speed
Pr.883
During regeneration avoidance
function operation
Description
Time
Time