Braking Time From Initial Velocity to Determined Speed
t
s
[Braking time] = s
J
red
[Inertia from load and motor at motor shaft] = kgm²
R´
[Transformed resistance] = Ω
K
M
[Torque constant motor] = Nm/A; see P-0-0051
z
p
Number of pole pairs motor; see P-0-0018
L
[Winding inductance motor] = H; see P-0-4016
ω
0
[Initial angular velocity motor] = s
-1
X
[Part of initial speed] = %
Fig.15-57:
Duration From Initial Speed to Speed X
Calculation with X = 0 results in infinite braking time, because the theoretical
speed characteristic is an asymptote tending to 0. The motor nevertheless
comes to standstill, because in practical application a friction torque takes ef‐
fect in addition to the braking torque due to ZKS (DC bus short circuit).
Check calculation by means of measurement
The calculation provides a result which can be used for the first
estimation of the braking behavior. Other influences, such as en‐
ergy balance in the DC bus, tolerances and environmental influ‐
ences, take effect on the actually occurring braking behavior.
Measure the actually occurring braking time in the installation!
DOK-INDRV*-SYSTEM*****-PR06-EN-P
Rexroth IndraDrive Drive Systems with HMV01/02 HMS01/02, HMD01, HCS02/03
Bosch Rexroth AG
279/309
Calculations
