Mitsubishi Electric FR-A800 Series Instruction Manual page 734

Pr.
Regeneration
882
avoidance operation
G120
selection
Regeneration
883
avoidance operation
G121
level
Regeneration
884 avoidance at
G122 deceleration detection
sensitivity
Regeneration
885 avoidance
G123 compensation
frequency limit value
886 Regeneration
G124 avoidance voltage gain
Regeneration
665
avoidance frequency
G125
gain
 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.
Regeneration avoidance operation
example for acceleration
Pr. 883
During regeneration
avoidance function operation
NOTE
• The slope of frequency rising or lowering by the regeneration avoidance operation will change depending on the regenerative
status.
• The DC bus voltage of the inverter will be approximately
The bus voltage is about 311 VDC (622 VDC) when the input voltage is 220 VAC (440 VAC). However, it may vary depending
on the input power supply waveform.
• Make sure that the setting value of Pr.883 will not get under DC bus voltage level. The frequency will rise with operation of the
regeneration avoidance function even during operation other than the regenerative operation.
• The stall prevention (overvoltage) (oL) will only operate during deceleration, stopping the lowering of output frequency, but on
the other hand, the regeneration avoidance function will constantly operate (Pr.882 = "1") or operate only at constant speed
(Pr.882 = "2"), and raise the frequency depending on the amount of regeneration.
• When the motor becomes unstable due to operation of the stall prevention (overcurrent) (OL) during the regeneration
avoidance operation, increase the deceleration time or lower the setting of Pr.883.
• During position control, the regeneration avoidance function is not activated.
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Name Initial value
0
200 V
380 VDC
class
400 V
760 VDC
class
0
6 Hz
100%
100%
Time
Time
search engine
Setting
range
0 The regeneration avoidance function is disabled.
1 The regeneration avoidance function is always enabled.
The regeneration avoidance function is enabled only during
2
constant-speed operation.
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
300 to 1200 V
be longer.
Set the setting value higher than the (power supply voltage ×
√
) value.
2
The regeneration avoidance is disabled due to bus voltage
0
change rate.
Set the sensitivity to detect the bus voltage change rate.
1 to 5 Setting value 1 (detection sensitivity: low) to 5 (detection
sensitivity: high)
Set the limit value for frequency to rise when the regeneration
0 to 590 Hz
avoidance function is activated.
9999 The frequency limit is disabled.
Adjust the response during the regeneration avoidance
0 to 200%
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
0 to 200%
suppress the vibration, set a smaller value in Pr.665.
Regeneration avoidance operation
example for constant speed
Pr. 883
During regeneration
avoidance function operation
√
times of the normal input voltage.
2
Description
Regeneration avoidance operation
example for deceleration
Pr. 883
Time
During regeneration
avoidance function operation
Time
5.16 (G) Control parameters
1
2
3
4
5
6
7
8
9
10
Time
Time
733
5. PARAMETERS