WEG CFW-11 Programming Manual page 91

Nominal U
Figure 9.11 - Example of the DC link voltage limitation working with the Ramp Hold function
2 - Ramp Acceleration:
It is effective in any situation, regardless of the motor speed condition, accelerating, decelerating or at
constant speed.
Working: the DC link voltage is compared with the value adjusted in P0151, the difference between these
signals is multiplied by the proportional gain (P0152) and the result is added to the ramp output. Refer to
the figures 9.12 and 9.13.
In a similar manner as the Ramp Hold, with this function an optimized deceleration time (minimum possible)
for the driven load is also obtained.
The use is recommended for loads that require braking torques in constant speed situation. Example: driving
of loads with eccentric shafts such as the existent in pumpjacks.
DC Link
Voltage (U )
d
P0151
Figure 9.12 - Limitation of the DC link voltage using Ramp Hold function block diagram
DC Link Voltage (P0004)
P0151
d
Output
Speed
P0152
Scalar Control (V/f)
F022 – Overvoltage
DC Link Regulation
Time
Time
Speed
Ramp Output
9
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