Calculation Of The Allowed Braking Power - ABB ACS800 Application Manual

16

Calculation of the allowed braking power

If drive is not connected to the main supply, ensure that the braking power meets
condition 1 below.
If drive is connected to the main supply, ensure the braking power meets condition 1
AND condition 2 below.
Condition 1
The drive braking power may not exceed the drive power rating.
≤
P
br
P
br
P
cont.max
Condition 2
The power flowing through the converter's DC bus terminals to the other drives may
not exceed the drive power rating. This might happen when drive brakes and takes
power from the main supply at the same time. The power rating of the terminals is
not exceeded when the following condition is valid, i.e. the sum of the drive input
power and the drive braking power has to be equal or smaller than the drive power
rating.
P +
1
-------------------------------------------------------- - P
P
br
P
cont.max
P
out.tot
P
1...n
Design
P
cont.max
= braking power
= drive power rating
...
P + + P – P
2 n br
⋅
P
out.tot
= braking power
= drive power rating
= power limit of the common DC system
= simultaneous loads of the other converters
≤
+ P P
cont.max br cont.max