ARKEL Elektrik Elektronik Ltd.
Ş
ti. www.arkel.com.tr
08.2012
ADrive
73
20.5. Improving travel comfort
Travel comfort depends on 2 main factors:
1.
Shape of the reference speed curve
2.
Ability to follow the reference speed curve reliably without vibrations
To achive a good travel comfort, initially a smooth driving without vibrations should be ensured
and then the reference speed curve must be adjusted to give the desired travel.
ADrive uses a PI (proportional-integral) controller to drive the motor trying to follow a reference
speed curve. At any given time, the PI controller needs two gain coefficients (KP and KI) to
calculate the voltage and frequency to be supplied to the motor. The limit values for these
coefficients should be entered to ADrive in the
“3-Controller setup”
menu:
“3.1-KP zero speed”
“3.2-KI zero speed”
“3.3-KP full speed”
“3.4-KI full speed”
These zero speed and full speed values are the limit values for the KI and KP gain coefficients.
The actual gain coefficient to be used at any moment is calculated instantaneously by
interpolating these limits by the current speed of the motor.
To adjust these limit values, the following practical procedure may be applied:
a)
Initially set these values:
“
3.1-KP0
” and “
3.3-KP1
” to 500
“
3.2-KI0
” and “
3.4-KI1
” to 10
“
3.9-Encoder filter
” to 2
b)
By pressing the up button on ADrive keyboard, find the
RPM Error Screen
. Give a
command to the elevator and observe the rpm error while the car is accelerating and
decelerating. If the rpm error goes beyond 5%, increase the KI and KP gain coefficients.
As the gain coefficients are increased, the controller will respond more quickly to the
difference between the reference and actual speed values. But if the coefficients are
increased too much, the actual speed will start to oscillate around the reference speed, noise
and vibrations will be felt on the motor.
In practice, it is suitable to use 1/60th to 1/30th of KP values as the KI values. If the
controller behaves differently between slow and high speeds, it is possible to use separate
values or zero speed and high speed.
Warning:
While travelling in inspection or recall modes, if you release the pressed (up or down)
button, the safety circuit will be cut-off and the contactors will drop suddenly. This will
cause the car to stop immediately and sometimes will cause the driver to give “Motor
current too high” or “IPM error” trips. This behaviour is normal. When immediate stopping
is not needed, you can make the car stop smoothly. To do this, instead of releasing the
pressed button, press the other button (up or down) too. When both buttons are pressed, the
car will slow down and come to a stop. After the car has fully stopped, you can release both
buttons.