3.4.5 Tuning Speed PID Control
The following tuning guidelines are relevant when using one of the flux motor control principles in applications where the
load is mainly inertial (with a low amount of friction).
The value of
30-83 Speed PID Proportional Gain
is dependent on the combined inertia of the motor and load. The selected
bandwidth can be calculated using the following formula:
Par. 7−02 =
Total inertia kgm2 x par. 1−25
Par. 1−20 x 9550
x Bandwidth rad /s
NOTICE!
1-20 Motor Power [kW]
is the motor power in kilowatts. For example, enter ‘4’ kW instead of ‘4000’ W in the formula.
A practical value for the bandwidth is 20 rad/s. Check the result of the
30-83 Speed PID Proportional Gain
calculation against
the following formula. This is not required if using a high resolution feedback such as a SinCos feedback.
Par. 7−02MAX = 0.01 x 4 x Encoder Resolution x Par. 7−06
2
x π
x Max torque ripple %
A good starting value for
7-06 Speed PID Lowpass Filter Time
is 5 ms. A lower encoder resolution calls for a higher filter
value. Typically a max torque ripple of 3% is acceptable. For incremental encoders, the Encoder Resolution is found in either
5-70 Term 32/33 Pulses Per Revolution
(24 V HTL on standard drive) or
17-11 Resolution (PPR)
(5 V TTL on MCB102 Option).
Generally the practical maximum limit of
30-83 Speed PID Proportional Gain
is determined by the encoder resolution and the
feedback filter time, but other factors in the application might limit the
30-83 Speed PID Proportional Gain
to a lower value.
To minimize the overshoot,
7-03 Speed PID Integral Time
could be set to approx. 2.5 s. Time varies with the application.
7-04 Speed PID Differentiation Time
should be set to 0 until everything else is tuned. If necessary, finish the tuning by
adjusting this setting in small increments.
Product Introduction
Design Guide
40
Danfoss A/S © Rev. 2014-02-10 All rights reserved.
MG34S222
3
3
Содержание VLT AutomationDrive FC 300
Страница 2: ......