Delta Electronics MVF2000 Series, Product Manual

Page: 72 / 136

lower than the speed specified by customer. When the modulation ratio is lower than
P0813, bypass derating is finish.

Minimum operating power factor for negative sequence compensation and minimum
operating speed for negative sequence compensation are the operating threshold of
negative sequence compensation. While the power factor or output speed is less than
threshold, VFD works in symmetrical bypass mode.
Table 4-69 Input under voltage derating
ID Parameter Min Max Unit Default Description
P0492
Input under voltage
derating enable
0 1 1
0-Disable
1-Enable
P0801
Voltage threshold of
input under voltage
derating
0 100 % 90
P0802
Modulation ratio of
speed deceleration
for input under
voltage derating
100 120 0.01 115
P0803
Modulation ratio of
speed maintenance
for input under
voltage derating
80 120 0.01 113

70%~90% is the detecting level of input under voltage. If the voltage drop within 30%
occurs while driving at high speed, VFD output speed will be decreased automatically.
Therefore, the actual motor speed becomes lower than the speed specified by customer.
When input voltage recovers, VFD output speed will increase to reference speed.
Table 4-70 Low voltage ride through
ID Parameter Min Max Unit Default Description
P0484
Threshold of input
power loss
100 900
‰
700
P0890
Low voltage ride
through enable
0 1 0
0-Disable
1-Enable
P0891
DC voltage lower
limit of low voltage
ride through
0 1300 V 400
P0892
Speed lower limit of
low voltage ride
through
0 100 % 5
P0893
Duration time of low
voltage ride through
0 65535 ms 1000
P0894
Ki coefficient of low
voltage ride through
field weakening loop
0 65535 % 100
P0895
Kp coefficient of low
voltage ride through
voltage loop
0 65535 % 100