Power Requirements; Dc Link Power P; Dc,Mot Of Motoring Axis; Dc,Gen Of Regenerating Axis - ABB ACSM1 System Manual

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Power requirements

In a common DC system several ACSM1 drive modules are connected to
DC link. Each drive and motor has its own specific load cycle profile. The
sum of these load cycles will define the system power profile in DC link as
shown in the figure below.
Drive
M

DC link power P

P
dc,mot
mechanical motoring power on the motor shaft. P
shaft power, because it covers also the losses in the ACSM1 and motor.
P
dc
k
eff
P
m
T
n
DC link power P
P
dc,gen
terminals. P
covers also the losses in the ACSM1 and motor.
Drive Drive
A B C
M M
of motoring axis
dc,mot
is the power supplied to the DC terminals to get the required
ACSM1 losses
Motor losses
P
dc,mot
P
m
: DC link power
: Efficiency factor (1/eff) to include ACSM1 and motor losses. If not known, value 1.25 can be
used.
: Motor mechanical shaft power
: Torque (Nm) on motor shaft
: Motor shaft speed (rpm)
of regenerating axis
dc,gen
is now the power supplied from the regenerating motor to the DC
is lower than the shaft power, because the shaft power now
dc,gen
ACSM1 losses
Motor losses
P
m
P
dc,gen
is higher than the
dc,mot
= ×
P k P
dc , mot eff m
×
T n
≈
P ( kW )
m
9550
P
= ×
P m
dc , gen
k
eff