User's Manual

30
5 Optimizing the Controller Response
5.1 Amplification setting of the current regulators
The adjustment a.c. amplification of the current regulators is done with the resistors R25
(standard 4.7kOhm) and R26 (standard 4.7kOhm) (see
Figure 16), where each resistor is part of a voltage divider. Smaller resistor values
increase the amplification. A response is seldom necessary here. Should, however, motors
with higher winding resistors are used, the motor heats up already in idle operation, as the
resistor of the winding, together with the inductance of the winding leads to high reactive
current.
Remedy is possible by increasing the amplification.
During the test stage, the fixed resistors can be replaced by potentiometers (25kOhm) and
in series production the values determined can be realized by fixed resistors.
Both resistors must have the same size. The accuracy must be 1% or higher.
For adjustment, increase the current amplification with low speed until an "oscillation”
becomes noticeable (a stronger motor noise starts with approx. 1kHz). Immediately reset
the amplification until the oscillation stops and a tick more.
5.2 Alternating Current Amplification of the Speed Controller
To adjust the amplification, couple the motor to load and define a set value of 0V. Turn the
potentiometer P3 to the right until the oscillation starts, immediately reset the amplification
until the oscillation (amplified motor noise because of rotary oscillation of the motor shaft
with approx. 200Hz) stops and a tick more.
5.3 Tachometer Filtering
The capacitor C21 is responsible for the tachometer filtering (see
Figure 16). When operating the drive with a three-phase tachometers a standard value of
22nF is enough. It allows a very good dynamic controller response.