Mitsubishi Electric FR-E800, Instruction Manual

Page: 447 / 484

446
16. (G) Control Parameters
16.9 Regeneration avoidance function
16.9
Regeneration avoidance function
The regenerative status can be detected and avoided by raising the frequency.
• The operation frequency is automatically increased to prevent the regenerative operations. This function is useful when a
load is forcibly rotated by another fan in the duct.
 Regeneration avoidance operation (Pr.882, Pr.883)
• When the regenerative voltage increases, the DC bus voltage will rise, which may cause an overvoltage fault (E.OV[]). The
regenerative status can be avoided by detecting this rise of bus voltage, and raising the frequency when the bus voltage
level exceeds
Pr.883 Regeneration avoidance operation level .
• The regeneration avoidance operation can be selected to operate constantly or operate only during constant speed.
• The regeneration avoidance function is enabled by setting "1 or 2" in
Pr.882 Regeneration avoidance operation
selection .
Pr. Name Initial value
Setting
range
Description
882
G120
Regeneration
avoidance operation
selection
0
0 The regeneration avoidance function is disabled.
1 The regeneration avoidance function is always enabled.
2
The regeneration avoidance function is enabled only during
constant-speed operation.
883
G121
Regeneration
avoidance operation
level
200 V
class
400 VDC
300 to 1200 V
Set the bus voltage level to operate the regeneration avoidance
operation. When the bus voltage level is set low, it will be harder
to generate overvoltage error, but actual deceleration time will
be longer.
Set the setting value higher than the (power supply voltage ×
) value.
400 V
class
780 VDC
575 V
class
944 VDC
885
G123
Regeneration
avoidance
compensation
frequency limit value
6 Hz
0 to 45 Hz
Set the limit value for frequency to rise when the regeneration
avoidance function is activated.
9999 The frequency limit is disabled.
886
G124 Regeneration
avoidance voltage gain
100% 0% to 200%
Adjust the response during the regeneration avoidance
operation. Increasing the setting improves the response to
change in the bus voltage. However, the output frequency may
become unstable. If setting a smaller value in
Pr.886 does not
suppress the vibration, set a smaller value in Pr.665 .
665
G125
Regeneration
avoidance frequency
gain
100% 0% to 200%
√
2
Pr. 883
Time
Time
Regeneration avoidance operation
example for acceleration
Bus voltage
(VDC)
Output
frequency(Hz)
During regeneration
avoidance function operation
Pr. 883
Time
Time
Regeneration avoidance operation
example for constant speed
Bus voltage
(VDC)
Output
frequency(Hz)
During regeneration
avoidance function operation
Pr. 883
Time
Time
Bus voltage
(VDC)
Output
frequency(Hz)
During regeneration
avoidance function operation
Regeneration avoidance operation
example for deceleration