WEG CFW700, Руководство по программированию и устранению неисправностей, Страница: 68 / 223

9
Scalar Control (V/f)
9-10 | CFW700
DC Link Voltage (P0004)
F022-
Overvoltage
Time
DC Link
Regulation
Output
Speed
Time
P0151
Nominal U
d
Figure 9.10: 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 9.11 and 9.12 .
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
)
P0152
P0151
Speed
Ramp Output
Figure 9.11: Limitation of the DC link voltage using Ramp Acceleration function block diagram