Table of Contents
Advertisement
In order to avoid this situation add a capacitor on the motor supply big enough to absorb the
overall energy flowing back to the supply. The capacitor must be rated to a voltage equal or
bigger than the maximum expected over-voltage and can be sized with the formula:
where:
U
- is the over-voltage protection limit expressed in [V]. You can read this value in the
MAX
"Drive Info" dialogue, which can be opened from the "Drive Setup".
U
- is nominal motor supply voltage expressed in [V]. You can read this value in the
NOM
"Drive Info" dialogue, which can be opened from the "Drive Setup".
E
- the overall energy flowing back to the supply in Joules. In case of a rotary motor
M
and load,
E
can be computed with the formula:
M
1
=
+
E
(J
J
)
M
M
L
2
Kinetic energy
where:
J
– total rotor inertia [kgm
M
J
– total load inertia as seen at motor shaft after transmission [kgm
L
ϖ
– motor angular speed before deceleration [rad/s]
M
m
– motor mass [kg] – when motor is moving in a non-horizontal plane
M
m
– load mass [kg] – when load is moving in a non-horizontal plane
L
g – gravitational acceleration i.e. 9.8 [m/s
h
– initial system altitude [m]
initial
h
– final system altitude [m]
final
I
– motor current during deceleration [A
M
R
– motor phase resistance [Ω]
Ph
t
– time to decelerate [s]
d
T
– total friction torque as seen at motor shaft [Nm] – includes load and transmission
F
© Technosoft 2007
≥
C
ϖ
+
+
(
m
m
)
g(h
M
M
L
Potential energy
2
]
×
2 E
M
2
2
−
U
U
MAX
NOM
−
-
h
)
initial
final
2
]
/phase]
RMS
19
ϖ
t
2
d
M
−
3I
R
t
Ph
d
M
2
Copper losses
Friction losses
2
]
IPS110 Technical Reference
T
F
Advertisement
Table of Contents
