Chapter 12 Description of Parameter Settings|CFP2000 Series
12.1-08-4
Settings 0.0~100.0%
This parameter defines an upper bound or limit for the integral gain (I) and therefore limits the
Master Frequency. The formula is: Integral upper bound = Maximum Output Frequency
(Pr.01-00) x (Pr.08-04 %).
Too large integral value will make the slow response due to sudden load change. In this way, it
may cause motor stall or machine damage.
PID Output Frequency Limit
Factory Setting:100.0
Settings 0.0~110.0%
This parameter defines the percentage of output frequency limit during the PID control. The
formula is Output Frequency Limit = Maximum Output Frequency (Pr.01-00) X Pr.08-05 %.
PID feedback value by communication protocol
Factory Setting: Read only
Settings -200.00%~200.00%
When PID feedback input is set as communication (Pr08-00=7 or 8), PID feedback value can be
set by this value.
PID Delay Time
Factory Setting: 0.0
Settings 0.0~35.0 sec
PID Mode Selection
Factory Setting: 0
Settings 0: Serial connection
1: Parallel connection
When setting is 0, it uses conventional PID control structure.
When setting is 1, proportional gain, integral gain and derivative gain are independent. The P, I
and D can be customized to fit users’ demand.
Pr.08-07 determines the primary low pass filter time when in PID control. Setting a large time
constant may slow down the response rate of drive.
Output frequency of PID control will filter by primary low pass function. This function could filter
mix frequencies. A long primary low pass time means filter degree is high and vice versa.
Inappropriate setting of delay time may cause system error.
PI Control: controlled by the P action only, and thus, the deviation cannot be eliminated entirely.
To eliminate residual deviations, the P + I control will generally be utilized. And when the PI
control is utilized, it could eliminate the deviation incurred by the targeted value changes and the
constant external interferences. However, if the I action is excessively powerful, it will delay the
responding toward the swift variation. The P action could be used solely on the loading system
that possesses the integral components.
PD Control: when deviation occurred, the system will immediately generate some operation load
that is greater than the load generated single handedly by the D action to restrain the increment
of the deviation. If the deviation is small, the effectiveness of the P action will be decreasing as
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