Functions, monitoring, and protective functions
9.3 Drive functions
Drive converter cabinet units
314
Operating Instructions, 07/07, A5E00288214A
9.3.2
Efficiency optimization
Description
The following can be achieved when optimizing efficiency using p1580:
●
Lower motor losses in the partial load range
●
Minimization of noise in the motor
˓
VHWS
LTVHWS
S[
S[
S
S
U
S[U
S[U
Figure 9-3
Efficiency optimization
It only makes sense to activate this function if the dynamic response requirements of the
speed controller are low (e.g., pump and fan applications).
For p1580 = 100%, the flux in the motor under no-load operating conditions is reduced to
half of the setpoint (reference flux) (p1570/2). As soon as load is connected to the drive, the
setpoint (reference) flux increases linearly with the load and, reaching the setpoint set in
p1570 at approx. r0077 = r0331 x p1570.
In the field-weakening range, the final value is reduced by the actual degree of field
weakening. The smoothing time (p1582) should be set to approx. 100 to 200 ms. Flux
differentiation (see also p1401.1) is automatically deactivated internally following
magnetization.
Function diagram
FP 6722
Field weakening characteristic, Id setpoint (ASM, p0300 = 1)
FP 6723
Field weakening control, flux control for induction motor (p0300 = 1)
Parameters
•
r0077
Current setpoints, torque-generating
•
r0331
Motor magnetizing current/short-circuit current (actual)
•
p1570
Flux setpoint
•
p1580
Efficiency optimization
