Speed Pid Differentiation Time; Speed Pid Diff. Gain Limit; Speed Pid Lowpass Filter Time - Danfoss VLT AutomationDrive FC 302 Programming Manual

Parameter Descriptions
7-03 Speed PID Integral Time
Range: Function:
leading to major deviations from the
required reference, since the process
regulator takes too long to regulate errors.
This parameter is used with [0] Speed open
loop and [1] Speed closed loop control, set in
parameter 1-00 Configuration Mode.

7-04 Speed PID Differentiation Time

Range: Function:
Size [0 - Enter the speed controller differentiation
related 200 ms] time. The differentiator does not react to
*
constant error. It provides gain proportional
to the rate of change of the speed
feedback. The quicker the error changes,
the stronger the gain from the differen-
tiator. The gain is proportional with the
speed at which errors change. Setting this
parameter to 0 disables the differentiator.
This parameter is used with
parameter 1-00 Configuration Mode [1] Speed
closed loop control.

7-05 Speed PID Diff. Gain Limit

Range: Function:
5 [1 - Set a limit for the gain provided by the differen-
*
20 ] tiator. Consider limiting the gain at higher
frequencies. For example, set up a pure D-link at
low frequencies and a constant D-link at higher
frequencies. This parameter is used with
parameter 1-00 Configuration Mode [1] Speed closed
loop control.

7-06 Speed PID Lowpass Filter Time

Range: Function:
NOTICE
Size [0.1
related - 100
*
Severe filtering can be detrimental to
ms]
dynamic performance.
This parameter is used with
parameter 1-00 Configuration Mode [1]
Speed closed loop and [2] Torque control.
Adjust the filter time in flux sensorless to
3–5 ms.
Set a time constant for the speed control low-
pass filter. The low-pass filter improves steady-
state performance and dampens oscillations on
the feedback signal. This is an advantage if
there is a great amount of noise in the system,
see Illustration 3.49. For example, if a time
constant (τ) of 100 ms is programmed, the cut-
off frequency for the low-pass filter is 1/0.1 =
10 RAD/s, corresponding to (10/2 x π) = 1.6 Hz.
The PID regulator only regulates a feedback
MG33MP02
Programming Guide
7-06 Speed PID Lowpass Filter Time
Range:
Danfoss A/S © 10/2018 All rights reserved.
Function:
signal that varies by a frequency of less than 1.6
Hz. If the feedback signal varies by a higher
frequency than 1.6 Hz, the PID regulator does
not react.
Practical settings of parameter 7-06 Speed PID
Lowpass Filter Time taken from the number of
pulses per revolutions from encoder:
Encoder PPR Parameter 7-06 Speed PID
Lowpass Filter Time
512 10 ms
1024 5 ms
2048 2 ms
4096 1 ms
Table 3.25 Speed PID Lowpass Filter Time
3 3
147