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System Manual – MOVIDRIVE® compact Drive Inverters
4
Overload capacity of the inverter
Project Planning
Example
Sample load cycle:
•
Overload current I
out 1
= 120 % I
D
•
Low-load current I
out 2
= 40 % I
D
•
Overload time t
1
= 0.75
×
T
•
Low-load time t
2
= 1.5
×
T
Continuous out-
put current
The thermal model in MOVIDRIVE
®
implements dynamic limiting of the maximum out-
put current. The maximum continuous output current I
D
is dependent on the PWM cycle
frequency, the ambient temperature
ϑ
amb
and the output frequency f
A
.
It is particularly important to take output frequencies f
A
< 2 Hz into account for:
•
Electrically stopping hoists
•
Torque control at low speeds or at a standstill
05550AXX
Figure 62: Sample load cycle
NOTE
The output frequency of the inverter when used with asynchronous motors is made up
of the rotational frequency (
Ⳏ
speed) and the slip frequency. With synchronous
motors, the output frequency of the inverter is the same as the rotational frequency of
the synchronous motor.
Summary of Contents for MOVIDRIVE compact MCH41A
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