Chapter 1: PREFACE AND GENERAL
Operating manual DC6AT
Page 7 of 28
EMF: electromotive force
L
Mot
: inductance of the motor (not relevant for the current observation)
U
kj
: terminal voltage of the motor
Real motor
=M
U
kl
EMF
L
Mot
I
Mot
R
V
EMF: electromotive force
L
Mot
: inductance of the motor (not relevant for the current observation)
R
V
: loss resistance of the motor (all losses of the motor combined)
U
kj
: Terminal voltage of the motor
I
Mot
: motor current
Unfortunately, real motors have losses (ohmic losses, magnetic losses, commutator losses)
that make it complicated to determine over the terminal voltage. However, if the resistance
R
V
is known, the necessary terminal voltage can be calculated as follows:
U
kl
= EMK +I
Mot
* R
V
Thus, the correction value I
Mot
* R
V
is added to the actual set value for the speed.
For good controlling behaviour of the drive controller, therefore, the correct setting of the pa-
rameter R
V
is very important. It contains not only the pure ohmic loss of the motor winding,
but represents all losses that occur in the motor.