BONFIGLIOLI active Applications Manual

06/05 19
06/05 19
5.1.3 Load estimate
The load estimate is done in the basic speed area. In order to avoid faults at a stand-
still and very low speeds, the load estimate is only done above a rotary frequency
limit, which can be set with the parameter
Fm lower value LE 813. The value is input
in per cent and is relative to the rated frequency of the machine.
Parameter Setting
No. Description Min. Max. Fact. sett.
813 Fm lower value LE 0 % 100 % 10 %
The load estimate starts above the rotary frequency given by the parameter
F
m lowe
r
value LS 813. The maximum time of the load estimate can be set with the parameter
Max Time LE 815. If the set time has been exceeded of if the basic speed area is left,
the determined
Load 243 is displayed. From it, the maximum admissible speed is
calculated.
Parameter Setting
No. Description Min. Max. Fact. sett.
815 Max time LE 0.001 s 65.000 s 2.000 s
With a constant stator current, the torque of the asynchronous machine is constant in
the basic speed area. Above it, it drops at 1/x, the output power remains constant.
The pull-out torque (T
break
) drops by 1/x² in the field-weakening area. With the re-
quired stator current (Parameter
I limit 818) the permitted rotary frequency is calcu-
lated from the P
const
characteristic. In addition, the limitation of the maximum speed
can be done with the pull-out torque, for which purpose a percentage relative to the
rated torque is entered in parameter
Pull-out torque at Fmax 816, this torque being
permitted at the
Maximum Frequency 419.
The permitted maximum speed is calculated in such a way that the characteristic given
by the Parameter
Pull-out torque at Fmax 816 is not exceeded.
T
f
f
R
2 f
R
3 f
R
4 f
R
T
const
P
const
T
break
parameter 816
f
R
T
R
Load
Parameter Setting
No. Description Min. Max. Fact. sett.
816 Pull-out torque at Fmax 0 % 100 % 100 %
If the parameter
Operation mode LE 822 is set to 1 or 2, the stationary end figure at
the maximum frequency then allowed is used for the calculation.
If the parameter
Operation mode LE 822 is set to 3 or 4, the additional torque for the
acceleration is taken into account. As the deceleration is re
garded as being particularly
critical, the set
Deceleration Anti-clockwise 423 is evaluated here.

BONFIGLIOLI active Specifications

General

Brand	BONFIGLIOLI
Model	active
Category	DC Drives
Language	English